What is Consuming Hydrogen and Acetylene on Titan / 06.03.10

Two new papers based on data from NASA’s Cassini spacecraft scrutinize the complex chemical activity on the surface of Saturn’s moon Titan. While non-biological chemistry offers one possible explanation, some scientists believe these chemical signatures bolster the argument for a primitive, exotic form of life or precursor to life on Titan’s surface. According to one theory put forth by astrobiologists, the signatures fulfill two important conditions necessary for a hypothesized “methane-based life.” One key finding comes from a paper online now in the journal Icarus that shows hydrogen molecules flowing down through Titan’s atmosphere and disappearing at the surface. Another paper online now in the Journal of Geophysical Research maps hydrocarbons on the Titan surface and finds a lack of acetylene.

This lack of acetylene is important because that chemical would likely be the best energy source for a methane-based life on Titan, said Chris McKay, an astrobiologist at NASA Ames Research Center, Moffett Field, Calif., who proposed a set of conditions necessary for this kind of methane-based life on Titan in 2005. One interpretation of the acetylene data is that the hydrocarbon is being consumed as food. But McKay said the flow of hydrogen is even more critical because all of their proposed mechanisms involved the consumption of hydrogen. “We suggested hydrogen consumption because it’s the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth,” McKay said. “If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth.”

To date, methane-based life forms are only hypothetical. Scientists have not yet detected this form of life anywhere, though there are liquid-water-based microbes on Earth that thrive on methane or produce it as a waste product. On Titan, where temperatures are around 90 Kelvin (minus 290 degrees Fahrenheit), a methane-based organism would have to use a substance that is liquid as its medium for living processes, but not water itself. Water is frozen solid on Titan’s surface and much too cold to support life as we know it. The list of liquid candidates is very short: liquid methane and related molecules like ethane. While liquid water is widely regarded as necessary for life, there has been extensive speculation published in the scientific literature that this is not a strict requirement.

The new hydrogen findings are consistent with conditions that could produce an exotic, methane-based life form, but do not definitively prove its existence, said Darrell Strobel, a Cassini interdisciplinary scientist based at Johns Hopkins University in Baltimore, Md., who authored the paper on hydrogen. Strobel, who studies the upper atmospheres of Saturn and Titan, analyzed data from Cassini’s composite infrared spectrometer and ion and neutral mass spectrometer in his new paper. The paper describes densities of hydrogen in different parts of the atmosphere and the surface. Previous models had predicted that hydrogen molecules, a byproduct of ultraviolet sunlight breaking apart acetylene and methane molecules in the upper atmosphere, should be distributed fairly evenly throughout the atmospheric layers.

imagery from Galileo showing emission of gases

Strobel found a disparity in the hydrogen densities that lead to a flow down to the surface at a rate of about 10,000 trillion trillion hydrogen molecules per second. This is about the same rate at which the molecules escape out of the upper atmosphere. “It’s as if you have a hose and you’re squirting hydrogen onto the ground, but it’s disappearing,” Strobel said. “I didn’t expect this result, because molecular hydrogen is extremely chemically inert in the atmosphere, very light and buoyant. It should ‘float’ to the top of the atmosphere and escape.”

Strobel said it is not likely that hydrogen is being stored in a cave or underground space on Titan. The Titan surface is also so cold that a chemical process that involved a catalyst would be needed to convert hydrogen molecules and acetylene back to methane, even though overall there would be a net release of energy. The energy barrier could be overcome if there were an unknown mineral acting as the catalyst on Titan’s surface. The hydrocarbon mapping research, led by Roger Clark, a Cassini team scientist based at the U.S. Geological Survey in Denver, examines data from Cassini’s visual and infrared mapping spectrometer. Scientists had expected the sun’s interactions with chemicals in the atmosphere to produce acetylene that falls down to coat the Titan surface. But Cassini detected no acetylene on the surface.

In addition Cassini’s spectrometer detected an absence of water ice on the Titan surface, but loads of benzene and another material, which appears to be an organic compound that scientists have not yet been able to identify. The findings lead scientists to believe that the organic compounds are shellacking over the water ice that makes up Titan’s bedrock with a film of hydrocarbons at least a few millimeters to centimeters thick, but possibly much deeper in some places. The ice remains covered up even as liquid methane and ethane flow all over Titan’s surface and fill up lakes and seas much as liquid water does on Earth. “Titan’s atmospheric chemistry is cranking out organic compounds that rain down on the surface so fast that even as streams of liquid methane and ethane at the surface wash the organics off, the ice gets quickly covered again,” Clark said. “All that implies Titan is a dynamic place where organic chemistry is happening now.”

The absence of detectable acetylene on the Titan surface can very well have a non-biological explanation, said Mark Allen, principal investigator with the NASA Astrobiology Institute Titan team. Allen is based at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Allen said one possibility is that sunlight or cosmic rays are transforming the acetylene in icy aerosols in the atmosphere into more complex molecules that would fall to the ground with no acetylene signature. “Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed,” Allen said. “We have a lot of work to do to rule out possible non-biological explanations. It is more likely that a chemical process, without biology, can explain these results – for example, reactions involving mineral catalysts.”

“These new results are surprising and exciting,” said Linda Spilker, Cassini project scientist at JPL. “Cassini has many more flybys of Titan that might help us sort out just what is happening at the surface.” The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

For more information about the Cassini-Huygens mission visit and

Jia-Rui Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.

Cathy Weselby 650-604-2791
NASA Ames Research Center, Moffett Field, Calif.

Life on Saturn’s Titan: Could It be Methane Based?
by Casey Kazan / March 20, 2010

Saturn’s giant moon Titan has water frozen as hard as granite and Great Lakes-sized bodies of fed by a complete liquid cycle, much like the hydrological cycle on Earth, but made up of methane and ethane rather than on water. Methane and ethane, the simplest hydrocarbon molecules, can assemble themselves into fantastically complex structures. Since complex hydrocarbons form the basis of life on Earth, scientists are wondering if hydrocarbon chemistry on Titan could have crossed the chasm from inanimate matter to some form of life? Titan has been considered a “unique world in the solar system” since 1908 when, the Spanish astronomer, José Comas y Solá, discovered that it had an atmosphere, something non-existent on other moons. It seems perfectly appropriate that one of the prime candidates for life in our solar system, Saturn’s largest moon, should have surface lakes, lightning, shorelines, relatively thick nitrogen atmosphere -and seasons. Titan can be viewed as an early-model Earth. And 100% of all known Earths have awesome life on them. The significantly lower temperature is a bit of a stumbling block (it’s ten times as far from the sun as us), but there’s a strong possibility of subterranean microbial life – or even a prebiotic “Life could happen!” environment. If a space traveler ever visits Titan, they will find a world where temperatures plunge to minus 274 degrees Fahrenheit, methane rains from the sky and dunes of ice or tar cover the planet’s most arid regions -a cold mirror image of Earth’s tropical climate, according to scientists at the University of Chicago.

Titan’s ice is stronger than most bedrock found on earth, yet it is more brittle, causing it to erode more easily, according to new research by San Francisco State University Assistant Professor Leonard Sklar. Sklar and his team developed new measurements from tests on ice as cold as minus 170 degrees Celcius which demonstrate that ice gets stronger as temperature decreases. Understanding ice and its resistance to erosion is critical to answering how Titan’s earth-like landscape formed. Titan has lakes, rivers and dunes, but its bedrock is made of ice as cold as minus 180 degrees Celcius, eroded by rivers of liquid methane. “You have all these things that are analogous to Earth. At the same time, it’s foreign and unfamiliar,” said Ray Pierrehumbert, the Louis Block Professor in Geophysical Sciences at Chicago. Titan, one of Saturn’s 60 moons, is the only moon in the solar system large enough to support an atmosphere. Pierrehumbert and colleague Jonathan Mitchell, have been comparing observations of Titan collected by the Cassini space probe and the Hubble Space Telescope with their own computer simulations of the moon’s atmosphere. “One of the things that attracts me about Titan is that it has a lot of the same circulation features as Earth, but done with completely different substances that work at different temperatures,” Pierrehumbert said. On Earth, for example, water forms liquid and is relatively active as a vapor in the atmosphere. But on Titan, water is a rock. “It’s not more volatile on Titan than sand is on Earth.”

Methane-natural gas-assumes an Earth-like role of water on Titan. It exists in enough abundance to condense into rain and form puddles on the surface within the range of temperatures that occur on Titan. “The ironic thing on Titan is that although it’s much colder than Earth, it actually acts like a super-hot Earth rather than a snowball Earth, because at Titan temperatures, methane is more volatile than water vapor is at Earth temperatures,” Pierrehumbert said. Pierrehumbert and Mitchell even go so far as to call Titan’s climate tropical, even though it sounds odd for a moon that orbits Saturn more than nine times farther from the sun than Earth. Along with the behavior of methane, Titan’s slow rotation rate also contributes to its tropical nature. Earth’s tropical weather systems extend only to plus or minus 30 degrees of latitude from the equator. But on Titan, which rotates only once every 16 days, “the tropical weather system extends to the entire planet,” Pierrehumbert said.

Titan’s dense, nitrogen-methane atmosphere responds much more slowly than Earth’s atmosphere, as it receives about 100 times less sunlight than Earth. Seasons on Titan last more than seven Earth years. Its clouds form and move much like those on Earth, but in a much slower, more lingering fashion. Physicists from the University of Granada and University of Valencia, analyzing data sent by the Cassini-Huygens probe from Titan, have “unequivocally” proved that there is natural electrical activity on Titan. The world scientist community believes that the probability of organic molecules, precursors of life, being formed is higher on planets or moons which have an atmosphere with electrical storms.

Scientists with NASA’s Cassini mission have monitored Titan’s atmosphere for three-and-a-half years, between July 2004 and December 2007, and observed more than 200 clouds. They found that the way these clouds are distributed around Titan matches scientists’ global circulation models. The only exception is timing — clouds are still noticeable in the southern hemisphere while fall is approaching. “Titan’s clouds don’t move with the seasons exactly as we expected,” said Sebastien Rodriguez of the University of Paris Diderot, in collaboration with Cassini visual and infrared mapping spectrometer team members at the University of Nantes, France. “We see lots of clouds during the summer in the southern hemisphere, and this summer weather seems to last into the early fall. It looks like Indian summer on Earth, even if the mechanisms are radically different on Titan from those on Earth. Titan may then experience a warmer and wetter early autumn than forecasted by the models.”

On Earth, abnormally warm, dry weather periods in late autumn occur when low-pressure systems are blocked in the winter hemisphere. By contrast, scientists think the sluggishness of temperature changes at the surface and low atmosphere on Titan may be responsible for its unexpected warm and wet, hence cloudy, late summer. Scientists will continue to observe the long-term changes during Cassini’s extended mission, which runs until the fall of 2010, which will offer plenty of opportunities to monitor climate change on Titan — the spacecraft makes its next flyby of the moon on June 6. We’ll learn if the sluggish weather is the result of a slow rate of temperature change at the surface.

Cassini results so far don’t show if Titan has an ocean beneath the surface, but scientists say this hypothesis is very plausible and they intend to keep investigating. Detecting tides induced by Saturn, a goal of the radio science team, would provide the clearest evidence for such a hidden water layer. “Additional flybys may tell us whether the crust is thick or thin todaf,” says Jonathan Lunine, a Cassini interdisciplinary investigator with the University of Rome, Tor Vergata, Italy, and the University of Arizona, Tucson. “With that information we may have a better understanding of how methane, the ephemeral working fluid of Titan’s rivers, lakes and clouds, has been resupplied over geologic time. Like the history of water on Earth, this is fundamental to a deep picture of the nature of Titan through time.”

{The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.}

The team found two types of bacteria living in Lost Hammer that feed off the methane and likely breathe sulfate.

Bacteria Suited for Life on Mars Discovered / June 9, 2010

Researchers in Canada and the United States have discovered that methane-eating bacteria survive in a unique spring located on Axel Heiberg Island in Northern Canada. Because the environment there is similar to possible past or present springs on Mars, scientists surmise that the “Red Planet” might also be able to support a form of life. Canadian and U.S. scientists say they’ve concluded life might survive on Mars since they’ve found evidence of bacteria in a martian-like environment on Earth. Researchers at Canada’s McGill University, the University of Toronto, the National Research Council of Canada and the SETI Institute in the United States say they have discovered methane-eating bacteria survive in a unique spring located on Axel Heiberg Island in Northern Canada. Lyle Whyte, a McGill microbiologist, said the Lost Hammer Spring supports microbial life — and the spring’s environment is similar to possible past or present springs on Mars. That, he said, means the “Red Planet” might also support a form of life. The Canadian spring’s sub-zero water is so salty it doesn’t freeze and it has no consumable oxygen in it. There are, however, big bubbles of methane that come to the surface, which had provoked the researchers’ curiosity as to whether the gas was being produced geologically or biologically and whether anything could survive in such an extreme hypersaline sub-zero environment. “We were surprised that we did not find methanogenic bacteria that produce methane at Lost Hammer,” Whyte said. “But we did find other very unique anaerobic organisms — organisms that survive by essentially eating methane and probably breathing sulfate instead of oxygen.”

{The research appeared in the International Society for Microbial Ecology Journal.}

Titan’s atmosphere oddity consistent with methane-based life
by John Timmer / June 4, 2010

Something strange is afoot in the atmosphere of Saturn’s moon Titan, according to data sent back from the Cassini mission. Data returned from a spectrometer on Cassini indicates that there’s a large flux of hydrogen in the moon’s atmosphere, with the gas forming in the upper atmosphere and being removed from the atmosphere at Titan’s surface. We don’t currently know what process is ensuring its removal, but the amounts of hydrogen being taken out of the atmosphere are consistent with an earlier proposal of methane-based life.

Titan’s atmosphere is rich in hydrocarbon compounds, and chemical changes in the upper atmosphere are driven by the arrival of ultraviolet light from the sun. One of the expected results of the UV exposure is the liberation of molecular hydrogen from methane via a process that produces more complex hydrocarbons. With little oxygen to react with, the molecular hydrogen should remain stable. Some of it will escape into space, but a new paper indicates that a substantial amount of that hydrogen migrates down through the atmosphere towards Titan’s surface. Since it’s not accumulating there, some chemical process must be removing it from the atmosphere; right now, we don’t know what that process is, and, as NASA’s own news piece on the topic notes, the first option for scientists is to consider simple chemistry.

However, the abstract of the paper notes that this level of hydrogen consumption is consistent with an earlier prediction of methanogenic life. In short, the life would get its energy by “burning” the hydrogen with a carbon source instead of oxygen, releasing methane (CH4) in the process. The source of the carbon is where a second paper (not yet online) comes in. Models of Titan’s upper atmosphere suggest that significant amounts of acetylene should be produced by the reactions there, and this would provide an excellent source of carbon to any hypothetical metabolisms. The surprise of the second paper is that there’s very little acetylene to be found on Titan’s surface. Two chemical enigmas certainly don’t constitute life, and the authors of the latter paper provide a variety of ways to account for the acetylene shortage that don’t involve an organism. It’s also important to remember that there won’t be anything resembling liquid water on the surface of Titan, so anything alive there would have to be living in a methane/ethane soup (not to mention at temperatures nearing -200°C).

Scientists are a cautious bunch, and it’s likely that these results will remain in limbo for a while. The discovery of plumes of methane in the atmosphere of Mars was another chemical enigma that might be evidence for life. It’s been about a year and a half since their announcement and nobody has come up with a satisfying explanation for their presence (at least as far as I’m aware), but the scientific community is nowhere close to ready to call that conclusive evidence for life.

Icarus, 2010. DOI: 10.1016/j.icarus.2010.03.003
Journal of Geophysical Research Atmospheres, 2010.10.1029/2009JE003369.

Mars makes methane: sign of life or geology at work?
by John Timmer / January 15, 2009

The more we look at the surface of the Red Planet, the more interesting things we’re finding there. The latest results haven’t even required a trip to Mars. Instead, a series of spectroscopy readings from telescopes in Hawaii have tracked changes in the composition of Mars’ atmosphere over time. To the researchers’ surprise, the Martian summer triggered large releases of methane into the atmosphere from three distinct regions on the planet. Right now, the researchers say they don’t have sufficient data to determine if the source of the methane is biological or geological.

The data themselves are being reported in a paper that is being released by Science today, and NASA hosted a press conference to describe them. The basic technique involved using a spectrometer hooked up to one of the large Hawaiian telescopes (over the span of several years of observations, they used several individual telescopes). They took samples from multiple pixels along the north-south axis to get one dimension of spatial resolution; the rotation of the planet itself provided a second. Absorption peaks from the gasses in the earth’s atmosphere were subtracted, leaving the signal from Mars’ atmosphere behind.

During the winter, the area of the spectrum that includes a signal of methane was basically a blank. But, as Martian summer arrived in the northern hemisphere, three distinct areas of the planet started showing signs of methane production. Eventually, three distinct atmospheric plumes appeared, representing a total of 19,000 metric tons of methane; the research suggests a production rate of over a half-kilogram of a second at its peak, a rate comparable to that of hydrocarbon seeps on earth.

As might be inferred from the low levels present in the winter, Mars doesn’t provide a hospitable environment for methane. The researchers estimate that, should this be a one-time only event, the methane that’s released would have a half life of four years; if this is an annual event, it must last less than a year. Given the oxidants found by the Mars Phoenix Lander and the dust storms that sweep that material into the sky on a regular basis, the authors suggest that it probably shouldn’t be viewed as a surprise that the methane doesn’t last.

So, where is it coming from? At the press conference, the NASA scientists noted that no plumes came from the area that’s normally covered by an ice cap during the Martian winter, so it’s not simply a matter of the source being blocked for part of the year. The areas where it does come from are within regions of the planet that have been found to have had liquid water in the past. Beyond that, however, the three plume sources seem to have little in common. The authors note that Terra Sabae has sub-surface hydrogen, Nili Fossae has hydrated minerals, and Syrtis Major has a volatile-rich substrate. Of course, it’s possible that there are small regions within these areas that do share some geochemistry. Mars is now tectonically dead, and the lack of sulfur dioxide suggests that the gas is not coming from any volcanic activity. Still, there is no way to rule out that some hot mantle material hasn’t come into contact with the regions’ residual water, which could create a steam reaction with minerals that could liberate water. On earth, however, these sorts of faults tend to create notable surface features, and cool fairly rapidly.

The alternative that springs to everyone’s mind is a biological source. The finding that bacteria can live at the bottom of South African mines provides a model cited by the authors. Radioactive activity could break apart water and release hydrogen, which the bacteria react with carbon dioxide to release energy, with methane as a byproduct. The problem for either of these cases is that the production of methane would be occurring several kilometers down in the crust, so it’s nothing that would be accessible to machinery NASA plans to send to Mars any time soon. Biological activity tends to involve lighter isotopes of elements, so it’s possible that mass spectroscopy of the methane might provide a clue, but getting a concentrated sample would be very difficult. It came out during the press call that one of the regions was a potential site for the Mars Science Lab that was eliminated late in the planning stages; since that mission has now been delayed until 2011, there’s a chance that decision will be revisited.

Although there’s no good way to distinguish among the possible sources, the finding is a clear indication that Mars remains an active planet, and liquid water is almost certainly associated with that activity. As Martian years take two on earth, scientists will be anxiously waiting to see whether the plumes return next Martian summer, an event that would rule out some of the more unlikely sources. In the mean time, the discovery will almost certainly inspire a lot of scientists to start thinking about a variety of chemical processes that could produce methane, and trying to determine ways to test whether any of those are operating on the red planet.

In the deep, a community of one
by John Timmer / October 9, 2008

As researchers probed a varity of environments that were once thought to be inhospitable to life, they were surprised to find large bacterial communities thriving in places like near-boiling hot springs and volcanic vents deep in the ocean. Faced with this evidence, it was fair to wonder just where the outer edges of survival might be. We may have a hint of that from samples taken from deep in South African mines, which show that life can make it nearly three kilometers down, but it’s far from the thriving communities we find in other extreme environments. In fact, it looks like the bacterial “community” in the mine may be comprised of a single species.

The authors of a paper describing the organism, to be published today in Science, can’t rule out the possibility that there are other microorganisms down in the mine, but their approach seems to make the possibility very unlikely. To start with, they filtered a total of 5,600 liters of mine water to get their sample, which gave other microbes plenty of opportunities to make themselves known. Of the DNA sequences obtained from this sample, over 99.9 percent were from this single species; over half of the remainder were obvious contaminants from their own lab. If anything else is there, it’s a small minority of the life present.

The bacteria, which goes by the name Candidatus Desulforudis audaxviator, is pretty homogeneous itself. Of 2.3 million bases present in the genome, all but 32 appeared to be identical in all of the population of bacteria that was sequenced. That’s a lower rate than the human population, and all the more striking given the amount of time that DNA has to pick up mutations; estimates of the nutrient availability (generated primarily from the energy given off during radioactive decay) indicate that it may take 100 to 1,000 years for a cell to divide.

With no other organisms present to engage in symbiosis with, the bacteria carry genes to do everything they need. They can make all the amino acids, extract useful carbon from carbon monoxide, and either fix nitrogen or obtain it from ammonia in the water. Oxygen is scarce in the environment, and the organism doesn’t appear to make any proteins that could possibly protect them from it. To run its metabolism, it reduces SO4. If it runs short of any of these, it has a flagella and chemosensory proteins that help it move off in search of more.

Extreme environments tend to be inhabited by archaea, so this bacteria is somewhat an exception to the rule. But the authors note that many of the key genes that enable it to survive in the hostile deeps of the mine actually originated in archaea, but were picked up by horizontal gene transfer. In this sense, it’s more of an exception that proves the rule. The fact that this organism requires such a diverse array of capabilities simply to survive, and is the only thing that manages to do so, suggests that this environment represents one of the outer edges of survivability for terrestrial life.

Extreme bugs back idea of life on Mars
by Kelly Young and David L Chandler / 07 December 2005

Methane-producing microbes have been discovered in two extreme environments on Earth – buried under kilometres of ice in Greenland and living in hot, dry desert soil. The findings lend weight to the idea that similar organisms may have lived on Mars. Live microbes making methane were found in a glacial ice core sample retrieved from three kilometres under Greenland by researchers from the University of California, Berkeley, US. It is the first time such archaea have been found at that depth, says Buford Price, one of the research team, which published its results in the Proceedings of the National Academy of Sciences (DOI: 10.1073/pnas.0507601102).

Scientists had already noticed that the concentrations of methane in the lowest 90 metres of the ice core was 10 times as high as that at other depths. Now the Berkeley scientists have found the likely cause – correspondingly higher levels of microbes that produce methane, known as methanogens. Areas of high methane concentration in the Martian atmosphere have been spotted by Europe’s Mars Express spacecraft, but its origin is uncertain. A renewable source of methane would be needed, as otherwise ultraviolet light from the Sun would have destroyed it within 340 years. The methane could come from a geological source, such as unseen volcanic activity, or biological sources such as methanogens.

Poor-man’s borehole
Price’s group used the data from Greenland to devise a scenario on Mars, in order to guide future missions. The methanogens in the ice cores existed at -10°C, but could produce more methane in warmer conditions. In order to account for the methane seen on Mars, they calculated the bugs would have to live at 0°C or above. This temperature is likely to occur between 150 metres and 8 kilometres beneath the Martian surface, depending on the rock type. It would then take between 15 years and 30,000 years for that methane to percolate up to the surface. “In my opinion, there’s no way in my lifetime that NASA will find a way of drilling a borehole 150 metres deep [on Mars],” Price told New Scientist. “But the poor-man’s borehole is just looking at what’s been thrown out of a crater.” So a spacecraft could be sent to a large crater where higher levels of atmospheric methane have been detected. The lander could then drill a shorter distance down into the crater to try to find evidence of life.

Desert dwellers
Another new study, reported in the journal Icarus (vol 178, p 277), has also discovered methanogens in a harsh environment on Earth. Researchers studied dozens of soil and vapour samples from five different desert environments in Utah, Idaho and California in the US, and in Canada and Chile. Of these, five soil samples and three vapour samples from the vicinity of the Mars Desert Research Station in Utah were found to have signs of viable methanogens. The methane in the vapour samples was 300 times higher than background levels. One of the team, Timothy Kral of the University of Arkansas, US, told New Scientist that dry conditions usually kill this type of microbe: “So finding them in a dry place is not what everyone would have expected.”

Methanogens require anaerobic (oxygen-free) environments to survive, and most combine carbon dioxide and hydrogen to generate energy. Kral explains that their samples were collected from possible anaerobic settings such as dry-channel deposits 70 centimetres underground. The surface of Mars is also very dry, so the finding helps support the idea that the methane detected there could be an indicator of current microbial activity. The lesson for Mars, says Andrew Knoll, a biogeochemist at Harvard University, US, and a member of the Mars rover science team, is that methanogenesis may be possible there, but only when the right conditions of a limited-oxygen environment and availability of nutrients occur.

A whiff of life on the Red Planet
by Jenny Hogan / 16 February 2005

A leading European Space Agency scientist says he has found a gas in the Martian atmosphere that he believes can only be explained by the presence of life. But the few researchers who have been privy to the facts say that such a conclusion is premature. Vittorio Formisano of the Institute of Physics and Interplanetary Science in Rome will be speaking next week at the first conference dedicated to the results from ESA’s Mars Express spacecraft. The craft has been orbiting the Red Planet since December 2003. Agustin Chicarro, the project scientist for Mars Express and the organiser of the conference in Noordwijk, the Netherlands, says he expects sparks to fly. “We have allocated one full hour of debate – it could be a lively discussion.”

Scientists are understandably cautious. The list of discredited claims for life on Mars is long: from canals built by intelligent beings that early astronomers thought they saw, to “bacteria fossils” found in a Martian meteorite that fell in Antarctica. The fossil-like structures, which were discovered in 1996, are now thought to have been etched by chemical processes. The debate reignited last year when three teams, including one led by Formisano, independently detected methane on Mars – a gas that bacteria produce on Earth. Some speculated that similar microbes could be producing the methane on Mars. But others argued that methane at the observed concentrations could be explained by non-biological processes producing about 150 tonnes of methane per year. A comet that crashed on Mars long ago or some kind of volcanic activity could supply that amount.

Soil-based life
Now Formisano is saying that there is much more methane on Mars. He bases this on the detection of a different gas, formaldehyde, by the Planetary Fourier Spectrometer (PFS), an instrument on Mars Express that he runs. Formisano averaged thousands of measurements taken by the PFS and calculated that the Martian atmosphere has formaldehyde in concentrations of 130 parts per billion. He thinks that the gas is being produced by the oxidation of methane and estimates that 2.5 million tonnes of methane per year are needed to produce it. “I believe that until it is demonstrated that non-biological processes can produce this, possibly the only way to produce so much methane is life,” he says. “My conclusion is there must be life in the soil of Mars.”

The presence of formaldehyde could explain why earlier studies found uneven distributions of methane on Mars, says Formisano. Because methane takes hundreds of years to break down by itself, the wind should even out the concentration of the gas around the planet. But if it is being oxidised in some regions, such as those that are rich in iron compounds, then you would find less methane in those areas. But other experts, including Formisano’s collaborators on the PFS and other principal investigators on the Mars Express mission to whom Formisano has presented his work, advise caution. He may be alone in pursuing formaldehyde, says one of his collaborators, Sushil Atreya from the University of Michigan, Ann Arbor, US.

Pushed to the limit
Others warn that Formisano is pushing the instrument to its limit in trying to look for formaldehyde. To identify compounds, the PFS looks for dark absorption lines in the spectrum of light reflected from Mars. Formaldehyde absorbs a handful of infrared wavelengths, but the instrument is not sensitive enough to see the individual lines. “It is not 100% convincing,” says Therese Encrenaz, from the Paris Observatory, France, another of Formisano’s colleagues. “But I think it deserves further work.”

Even if Formisano has found formaldehyde, it is not necessarily coming from the oxidation of methane. And even if there are large amounts of methane on the Red Planet, it might not be biological in origin. “Frankly, we don’t know what the internal geology of Mars is like. To draw conclusions on whether it is biological or not at this stage is damn risky,” says Michael Mumma of NASA’s Goddard Space Flight Centre in Greenbelt, Maryland, US, who last year found methane on Mars using Earth-based telescopes.

Formisano agrees that he has no conclusive proof. “I cannot demonstrate for sure,” he says. “But these hints for life I have found are the best one can get. The next step is to go there and look for it.” Future missions, such as NASA’s Mars Science Laboratory now in the planning stage, will look for and analyse organic molecules in the soil. While other evidence suggests that Mars was and may still be hospitable to life, ESA is playing it safe. “If this issue was a bit less controversial, then maybe we would be at the point of having some kind of press conference,” says Chicarro. “But we need to leave the scientific community to its natural course and have it debated there.” Debate at next week’s conference is certain.

Crater Critters: Where Mars Microbes Might Lurk
by Robert Roy Britt / 20 December 2005

The more scientists have learned about Mars in recent years, the more some believe that finding life might involve a deep drilling project. With the surface of the red planet desolate and mostly dry, one consistently appealing idea has been that pockets of underground water might harbor microbes. The problem is, studies have suggested reaching the pockets might require drilling a thousand feet (hundreds of meters) below the surface. P. Buford Price, a physics professor at the University of California, Berkeley, has an idea for another place to look. If there is any life in the belly of Mars, some of it might be found around meteor craters, where rock has been tossed up from deep down.

The idea fits with recent suggestions by European scientists that pockets of methane in Martian air could be signs of life below. Methane should not last more than 300 years in the atmosphere, so the concentrations of it suggest a source that might be biological, the Europeans reason. On Earth, even in solid rock 660 feet (200 meters) below the surface, methanogens have been found to thrive. Methanogens are ancient relatives of bacteria that take in hydrogen and carbon dioxide and emit methane. Price and his colleagues have found that the same creatures deep in Antarctic ice emit enough methane to affect concentrations of the gas detected in drilling projects. Methane pockets in ice cores taken from Greenland registered levels of the gas that in spots were 10 times higher than expected. “We found methanogens at precisely those depths where excess methane had been found, and nowhere else,” Price said.

Craters already dug
While Earth and Mars are very different places, and no one knows whether the source of the methane on Mars has anything to do with life (it could be geologic in nature) Price figures the whole thing can be tested out without the need to drill too far down. Under Antarctic ice, his team was able to detect concentrations of methanogens as low as 16 per cubic inch. “Detecting this concentration of microbes is within the ability of state-of-the-art instruments, if they could be flown to Mars and if the lander could drop down at a place where Mars orbiters have found the methane concentration highest,” Price said. “There are oodles of craters on Mars from meteorites and small asteroids colliding with Mars and churning up material from a suitable depth, so if you looked around the rim of a crater and scooped up some dirt, you might find them if you land where the methane oozing out of the interior is highest.” The idea was published online earlier this month by the journal Proceedings of the National Academy of Sciences.

Bizarre Creature in Idaho Raises Prospects for Life on Mars
By Robert Roy Britt / 16 January 2002

They eat hydrogen, breathe carbon dioxide, and belch methane. And they form the root of an ecosystem unlike any previously known on Earth. Meet the methanogen, a tiny organism living in complete darkness 660 feet (200 meters) underneath the surface of Idaho. Researchers report in the Jan. 17 issue of the journal Nature the discovery of a community of various organisms dominated and supported by these methanogens, creatures they say could represent just the sort of life to look for when turning over rocks on Mars. The work, along with another report this week of life found in extreme conditions in Antarctica, adds to mounting evidence for life’s tenacity and creativity, fueling increased speculation about the prospects for life on other worlds.

Extreme diet
Unlike other organisms at the bottom of the food chain, methanogens need little of the traditional sustenance that biologists associate with life. They get by without oxygen and no help from sunlight, said the U.S. Geological Survey’s Francis H. Chapelle, who led the study along with Derek Lovley of the University of Massachusetts. Methanogens simply feed off hydrogen in the rocks around an underground hot spring. No one knew if life could live in such conditions. So the Idaho site was chosen for its lack of organic matter, stuff that is originally produced by sunlight-powered organisms and is known to support other subsurface ecosystems. “This kind of microbial community has never been found on Earth,” Chapelle told, adding that it “may be representative of the kinds of life that initially evolved on the early Earth, and which may presently occur on Mars or Europa.”

Methanogens belong to an ancient group related to bacteria, called the archaea. All archaea are outfitted for survival in extreme environments. They are thought to have dominated primitive Earth, when oxygen was a rare commodity. Idaho is not the only home to methanogens. They cause gas in the digestive tracts of humans. And they’re found in oxygen-deprived mud at the bottom of swamps. But they are not seen as essential to supporting other life in these environments, as is the case in Idaho.

Life as we know it
Places considered most likely to harbor extraterrestrial life — pockets of underground water on Mars or an ocean under the frozen crust of Jupiter’s moon Europa — are only presumed to exist, and since they exist below the surface and get no sunlight, any life there would have to have an alternative means of fuel. The new finding shows that the recipe for life is simpler than previously thought, that sunlight is not needed, and that improves the prospects for finding ET, researchers said. “Hydrogen may well be an important requirement for extraterrestrial life,” Chapelle said.

And hydrogen is everywhere. It’s the most abundant element in the universe. Importantly, preliminary data recently sent back by the Mars Odyssey spacecraft suggests there may be a wealth of hydrogen within 3 feet (1 meter) of the surface of Mars, just south of the permanently frozen north polar region. Other studies have shown Mars and Europa might both contain suitable hydrogen-rich environments. “If hydrogen is indeed present on Mars in association with liquid water, the kind of metabolism we describe … may occur on Mars,” Chapelle said. William B. Whitman, a University of Georgia microbiologists who was not involved in the new study, said methanogens were hypothesized to exist in environments like the one studied in Idaho, but that it was unusual that they dominate the community of microbes within which they live. “This community composition has not been described before,” Whitman said. And what does it say about life as we know it? “It certainly strengthens the rationale for looking in more kinds of places, especially the subsurface of some of the other planets,” Whitman said.

Wild life
The methanogen discovery is one in a long string of findings over the past two decades showing how resilient and creative life can be. Researchers have found simple organisms in relatively dry valleys of Antarctica, in pockets of water under permanent packs of ice, deep inside Earth and huddled around hydrothermal vents at pitch-black ocean bottoms. Growing knowledge of Mars and recent findings on Earth bolster notions that the Red Planet may be the best place to look for similar extremophiles, as they are called.

Earlier this week, an international team of researchers said they had discovered organisms clinging to life in frigid, salty soil in Antarctica. Average temperatures in the Quartermain Mountains, where the microorganisms were found, are typically less 22 degrees below zero Fahrenheit (-30 C). Less than a half-inch of precipitation falls each year. No place on Earth is more like Mars, the researchers said. The study uncovered fungi and a common bacteria living just below the surface in salt-laden soil, which dramatically lowers the freezing temperature of water by a method not completely understood. The researchers say the same phenomenon may occur on Mars. Other research suggests that soil conditions on parts of Mars could be very similar to the Antarctic dirt. “The glacial climates of Antarctica would have led to glaciers that produced the same kinds of surfaces that were sampled in Antarctica and that we see on Mars today,” said Victor R. Baker of the Lunar and Planetary Lab at the University of Arizona. The Antarctic finding, led by William C. Mahaney of York University in Canada, will be presented in the journal Icarus. Baker and other geologists helped Mahaney interpret the discovery in the context of the potential for life on Mars.

Waiting game
Whether life exists beyond Earth is the greatest question in the minds of many scientists. No other single question channels more funding for space-related scientific research. Yet while the prospects for ET seem to grow with each new discovery on Earth, the plain fact is nobody knows if Mars does or ever did harbor life. Solid evidence could come from robotic probes. NASA alone has several planned over the next decade. Yet many researchers say a human mission to Mars — which is not even in the planning stages at NASA — might be required to literally dig up the necessary evidence. Oxygen-breathing creatures might be wise not to hold their breath for an answer to the ultimate question.

New Life Form Found in Mars-Like Conditions
by Robert Roy Britt / 31 July 2003

Leave it to California to come up with creatures that could be from Mars. Leave it to scientists to make them green. A new species of bacteria has been discovered thriving without oxygen in the harsh waters of northern California’s Mono lake, where conditions perhaps resemble places on the red planet that might support similar life forms, scientists announced Wednesday. A dye used in the laboratory to sort living things from dead stuff rendered the creatures green in an image released by NASA. Under a microscope, the bacteria look like miniature corkscrews winnowing through samples of the highly alkaline water in which they thrive.

There is no solid evidence for life on Mars, so discussion of it is speculative. But on Earth in recent years, researchers have found several species of “extremophiles,” microorganisms that exist in conditions most living things cannot tolerate. The newfound extremophile, called Spirochaeta americana, swims in a high-mineral, salty environment where the pH can reach 10.5, compared to a range of 6.5 to 7.5 that is generally suggested for backyard hot tubs and swimming pools. “The environment these bacteria inhabit would be distinctly inhospitable to many other life forms, including humans,” said Elena Pikuta, a microbiologist at the University of Alabama in Huntsville. Spirochaeta americana joins a growing list of organisms on Earth that don’t mind extreme heat, cold, darkness or other awful conditions. They are ancient life forms that have endured most of what the planet can throw at them. Extremophiles have been found under Antarctic ice, around superhot volcanic vents, eating rock beneath the sea floor munching on hydrogen and belching methane inside Earth’s crust, and even in the waste from nuclear reactors.

Yet fragile
The new species was discovered in a laboratory by analyzing water and mud collected during a single day’s visit to the lake. Outside their native habitat, the hardy creatures turn out to be surprisingly fragile. “These extremely thin and graceful bacteria move with an elegant motion,” Pikuta said. “Their cell walls are very delicate, and it is difficult to keep them alive for long periods in the laboratory.” It is primarily their ability to survive without oxygen that interests astrobiologists, those who study how and whether life might arise beyond Earth. “Since other bodies of the solar system [planets and moons] lack our oxygen-rich atmosphere, microorganisms that thrive without oxygen are good candidates for astrobiology research,” said Richard Hoover, an astrobiologist at NASA’s Marshall Space Flight Center. “If, or when, we find life on other planets, our first discoveries will probably be microorganisms.” Hoover worked with Pikuta on the study, which was published in the May issue of the International Journal of Systematic and Evolutionary Microbiology.

Mono Lake is not like anything known on Mars. But there are is some common ground. Mono is the remnant of a much larger lake whose water level in the Pleistocene era was some 427 feet (130 meters) higher. Some scientists have speculated that depressions seen on Mars might be sites of former lakes. Much of NASA’s Mars program is currently geared toward finding places on the red planet where liquid water might exist. Water is one ingredient needed by all life as we know it. But even if there is liquid water on Mars, that does not guarantee life. “Planets like Mars have conditions that would challenge the existence of highly organized multicellular organisms such as we find on Earth, but that doesn’t mean these harsh places can’t sustain microbial life forms,” Hoover said. “By studying microorganisms found in Earth’s extreme places, like Mono Lake, we can better understand how life might exist on Mars.”

Have We Discovered Evidence For Life On Titan
by Chris McKay / Jun 08, 2010

Recent results from the Cassini mission suggest that hydrogen and acetylene are depleted at the surface of Titan. Both results are still preliminary and the hydrogen loss in particular is the result of a computer calculation, and not a direct measurement. However the findings are interesting for astrobiology.
Heather Smith and I, in a paper published 5 years ago (McKay and Smith, 2005) suggested that methane-based (rather than water-based) life – ie, organisms called methanogens – on Titan could consume hydrogen, acetylene, and ethane. The key conclusion of that paper (last line of the abstract) was “The results of the recent Huygens probe could indicate the presence of such life by anomalous depletions of acetylene and ethane as well as hydrogen at the surface.”

Now there seems to be evidence for all three of these on Titan. Clark et al. (2010, in press in JGR) are reporting depletions of acetylene at the surface. And it has been long appreciated that there is not as much ethane as expected on the surface of Titan. And now Strobel (2010, in press in Icarus) predicts a strong flux of hydrogen into the surface. This is a still a long way from “evidence of life”. However, it is extremely interesting. Benner et al. (2004) first suggested that the liquid hydrocarbons on Titan could be the basis for life, playing the role that water does for life on Earth. Those researchers pointed out that “… in many senses, hydrocarbon solvents are better than water for managing complex organic chemical reactivity”.

Two papers in 2005 followed up on this logic by computing the energy available for methanogenic life based on the consumption of both the organics in Titan’s atmosphere along with the hydrogen in the atmosphere (McKay and Smith, 2005; Schulze-Makuch and Grinspoon, 2005). Both papers made the case that H2 on Titan would play the role that O2 plays on Earth. On Earth organisms (like humans) can react O2 with organic material to derive energy for life’s functions. On Titan organisms could react H2 with organic material to derive energy. The waste product of O2 metabolism on Earth is CO2 and H2O; on Titan the waste product of H2 metabolism would be CH4. As a result of the Cassini mission, there is now abundant evidence for CH4, even in liquid form, on Titan.

Organic molecules on the surface of Titan (such as acetylene, ethane, and solid organics) would release energy if they reacted with hydrogen to form methane. Acetylene gives the most energy. However this reaction will not proceed under ordinary conditions. This is similar to our experience on Earth. Consider a chocolate bar in a jar full of air. The organics in the chocolate would release energy if they reacted with the oxygen in the air but the reaction does not proceed under normal conditions. There are three ways to make it proceed: heat it to high temperatures (fire), expose it to a suitable metal catalyst that promotes the reaction, or eat it and use biological catalysts to cause the reaction. Biology can thrive in an environment that is rich in chemical energy but requires a catalyst for the chemical energy to be released. Such is the case on Titan.

McKay and Smith (2005) predicted that if there were life on Titan living in liquid methane then that life should be widespread on the surface because liquid methane is widespread on the surface. We have direct evidence that the surface of Titan at the landing site of the Huygens Probe near the equator was moist with methane, and radar and near-infrared imagery from Cassini have revealed extensive polar lakes on Titan, both north and south. Methane-based life would have a lot of environments in which to live. Again, this is analogous to Earth. Life is widespread on Earth because it uses water and water is widespread on Earth.

Furthermore, because it is widespread, life on Earth, in turn, has a profound effect on the environment. For example, each spring the amount of CO2 in the atmosphere drops as plants consume it to form leaves; each autumn, the amount of CO2 in the atmosphere goes up as these leaves decompose. That is, because of the ubiquity of life, the Earth breathes: one breath in during the spring, one breath out during the autumn. Widespread life has observable effects. Taking this logic to Titan, McKay and Smith (2005) predicted that Titanian life at the surface would consume near-surface hydrogen and that this might be detectable. The depletion of hydrogen is key because all the chemical methods suggested for life to derive energy from the environment on Titan involve consumption of hydrogen (McKay and Smith 2005; Schulze-Makuch and Grinspoon 2005). Acetylene, ethane, and solid organic material could all be consumed as well. Acetylene yields the most energy, but all give enough energy for microorganisms to live.

A few notes about liquid methane based life on Titan. First, while such life would produce CH4 it would not be a net source of CH4 but would be merely recycling C back into CH4 – undoing the photochemistry caused by sunlight in the upper atmosphere. It does not explain the persistence of CH4 on Titan over geological time. Second, it is impossible to predict any isotopic effect that this life might have on C. On Earth, methanogens produce CH4 from CO2+H2, or from organic material derived from CO2. The net reaction is CO2 + 4H2 => CH4 + 2H2O and thus methanogens on Earth are a net source of CH4 in a world of CO2. The enzymes that mediate these reactions create methane with a large isotopic enrichment of 12C over 13C of ~5%.

On Titan, it has been predicted that methanogens would produce CH4 by C2H2 + 3H2 => 2CH4 (eg. McKay and Smith 2005). This is obviously not a net source of CH4: it merely recycles CH4, thereby undoing the photolysis of CH4 and there is no a priori reason to expect the resulting CH4 to exhibit an isotopic shift from these reactions. The C-C bond in acetylene is strong but this by itself does not imply a strong isotopic selectivity. For example, life on Earth breaks the strong bond between the N atoms in N2 without leaving a clear isotopic effect. Thus, the istopic state of C on Titan is not relevant to the question of the presence of Titanian methanogens..

The data that suggests that there is less ethane on Titan than expected is well established (Lorenz et al. 2008). Photochemical models have predicted that Titan should have a layer of ethane sufficient to cover the entire surface to a thickness of many meters but Cassini has found no such layer. The new results of Clark et al. (2010) find a lack of acetylene on the surface despite its expected production in the atmosphere and subsequent deposition on the ground. There was also no evidence of acetylene in the gases released from the surface after the Huygens Probe landing (Niemann et al. 2005, Lorenz et al. 2006). Thus, the evidence for less ethane and less acetylene than expected seems clear and incontrovertible.

The depletion of ethane and acetylene become significant in the astrobiological sense because of this latest report of a hydrogen flux into the surface This is the key that suggests that these depletions are not just due to a lack of production but are due to some kind of chemical reaction at the surface. The determination by Strobel (2010) that there is a flux of hydrogen into the surface of Titan is not the result of a direct observation. Rather it is the result of a computer simulation designed to fit measurements of the hydrogen concentration in the lower and upper atmosphere in a self-consistent way. It is not presently clear from Strobel’s results how dependent his conclusion of a hydrogen flux into the surface is on the way the computer simulation is constructed or on how accurately it simulates the Titan chemistry.

In conclusion, there are four possibilities for the recently reported findings, listed in order of their likely reality:
1. The determination that there is a strong flux of hydrogen into the surface is mistaken. It will be interesting to see if other researchers, in trying to duplicate Strobel’s results, reach the same conclusion.
2. There is a physical process that is transporting H2 from the upper atmosphere into the lower atmosphere. One possibility is adsorption onto the solid organic atmospheric haze particles which eventually fall to the ground. However this would be a flux of H2, and not a net loss of H2.
3. If the loss of hydrogen at the surface is correct, the non-biological explanation requires that there be some sort of surface catalyst, presently unknown, that can mediate the hydrogenation reaction at 95 K, the temperature of the Titan surface. That would be quite interesting and a startling find although not as startling as the presence of life.
4. The depletion of hydrogen, acetylene, and ethane, is due to a new type of liquid-methane based life form as predicted (Benner et al. 2004, McKay and Smith 2005, and Schulze-Makuch and Grinspoon 2005).

+ Benner, S.A., A. Ricardo and M.A. Carrigan (2004) Is there a common chemical model for life in the universe? Current Opinion in Chemical Biology 8, 672-689. Clark, R. N., J. M. Curchin, J. W. Barnes, R. Jaumann, L. Soderblom, D. P. Cruikshank, R. H. Brown, S. Rodriguez, J. Lunine, K. Stephan, T. M. Hoefen, S. Le Mouelic, C. Sotin, K. H. Baines, B. J. Buratti, and P. D. Nicholson (2010) Detection and Mapping of Hydrocarbon Deposits on Titan. J. Geophys. Res., doi:10.1029/2009JE003369, in press.
+ Lorenz, L.D., H.B. Niemann, D.N. Harpold, S.H. Way, and J.C. Zarnecki (2006) Titan’s damp ground: Constraints on Titan surface thermal properties from the temperature evolution of the Huygens GCMS inlet. Meteoritics and Planetary Science 41, 1705-1714.
+ Lorenz, R.D., K.L. Mitchell, R.L. Kirk, A.G. Hayes, O. Aharonson, H.A. Zebker, P. Paillou, J. Radebaugh, J.I. Lunine, M.A. Janssen, S.D. Wall, R.M. Lopes, B. Stiles, S. Ostro, G. Mitri, and E.R. Stofan (2008) Titan’s inventory of organic surface materials Geophys. Res. Lett. 35, L02206, doi:10.1029/2007GL032118. McKay, C.P., Smith, H.D. (2005) Possibilities for methanogenic life in liquid methane on the surface of Titan. Icarus, 178, 274-276.
+ Niemann H. B., Atreya S. K., Bauer S. J., Carignan G. R., Demick J.E., Frost R. L., Gautier D., Haberman J. A., Harpold D. N., Hunten D. M., Israel G., Lunine J. I., Kasprzak W. T., Owen T.C., Paulkovich M., Raulin F., Raaen E., and Way S. H. (2005) The abundances of constituents of Titan’s atmosphere from the GCMS instrument on the Huygens probe. Nature 438, 779-784.
+ Schulze-Makuch, D., and D.H. Grinspoon (2005) Biologically enhanced energy and carbon cycling on Titan? Astrobiology 5, 560-564.
+ Strobel, D.F. (2010) Molecular hydrogen in Titan’s atmosphere: Implications of the measured tropospheric and thermospheric mole fractions. Icarus, in press.

Mars Underground: The Harsh Reality of Life Below
by Robert Roy Britt / 08 March 2004

If there is life on Mars, it certainly hasn’t jumped out and mugged for the Mars rovers’ cameras like many people had hoped. And most scientists agree it probably won’t. In fact, any critters that lurk on the red planet today would almost certainly be part of an underground organization that has defied long odds and the harsh realities of a very unfriendly world.

So why all the excitement last week over once soggy rocks at Meridiani Planum? After all, scientists already knew Mars once held a lot of water. The evidence is written all over the planet as scars of river erosion. All that’s really new is scientists now know of a specific location where water was abundant. Yet for some biologists, it isn’t just the signature of ancient water at Opportunity’s landing site that is exciting. It’s also the salt that was left behind. Water and salt — specifically lots of what scientists call sulfates — together can make brine. And brine is great stuff if you are a certain type of microbe. While neither water nor brine actually imply life, fresh shafts of optimism now shine on the possibility that an ancient soup of organic materials might have allowed the genesis of microscopic organisms, which could still dwell in the belly of the red planet.

Pass the salt, please
Road crews lay down salt because it lowers the freezing temperature of water. The same is true of brine. And that’s handy on a planet where the average global temperature is minus 63 degrees Fahrenheit (-53 C). Briney underground reservoirs might have existed for long periods of time, according to computer models. Significant pockets might remain today. Importantly, there are organisms on Earth that thrive in environments so salty they’d make a McDonald’s French fry cringe. They’re called halophiles (pronounced halo-files). Rocco Mancinelli of the SETI Institute studies these salt-resistant organisms. They are hardy, and hardly rare.

In a telephone interview last week, Mancinelli explained that halophiles are represented in all three primary domains of life — Bacteria, Eukarya and Archaea, but that each has developed different ways of dealing with high-salt environments. That suggests the trait “probably arose more than once,” he says, and so it is likely something that originates and develops easily. “Such a trait could easily have evolved in a Martian organism as well,” Mancinelli said. That is, he quickly added, assuming there ever were any Martian organisms. Halophiles are interesting to Mancinelli in part because if life ever did begin on Mars, an evolving ability to endure higher and higher concentrations of salt might have been needed to allow organisms to survive to the present.

Here’s why: Early in its history, Mars almost certainly had more water at or near the surface. There might have been lakes or seas, and probably rivers — at least in brief episodes. If there was no standing surface water, then at least there was more underground water than today, as last week’s rover discovery shows. Where there is water, minerals dissolve in it. When the water on Mars evaporated into outer space or retreated underground — nobody is sure where it all went — what remained would gradually have developed a higher concentration of dissolved salts, Mancinelli explains. “When the concentration gets high enough, most organisms would die,” he said. Halophiles, in this scenario, would get the planet to themselves. In one terrestrial example of this, scientists recently found a previously unknown form of life thriving in California’s Mono Lake, which has been slowly receding for decades, leaving a high concentration of minerals and salt that other organisms can’t take.

The element of time
Mancinelli thinks brine pockets probably remain deep beneath the surface of Mars today. Some might have lasted for hundreds of millions of years. “These brine pockets may be moving around. They may merge and separate.” But their suspected endurance is important, as would have been the duration of any surface seas. Like water, time may be a crucial aspect to life. Nobody knows exactly when or how life on Earth began, but the oldest record of it dates back roughly 3.5 billion years on a planet that’s been around for 4.5 billion years. Mars was born about the same time, just after the Sun formed. For how much of that time on early Earth were the ingredients of life present, and how long did it take Nature to make the jump from chemicals and minerals to living cells? Likewise, how long might it have taken for life on Mars to develop, if it ever did? “I don’t know,” Mancinelli said, “because we really don’t know how long it takes for life to originate and evolve.”

There are suggestions, however. In 1953, Stanley Miller conducted a landmark experiment in biology. Wondering what might have been the original spark for life, he combined methane, hydrogen and ammonia — substances then thought to dominate the young planet — with water, and sent flashes of electricity through it all. Overnight, things changed. In a series of experiments, Miller eventually cooked up 13 of the 31 amino acids needed for life. Neither Miller nor anyone else has figured out what actually triggered life, but the experiments suggested that with certain ingredients and perhaps a little lightning, some pretty magical stuff can happen.

The window for life
Miller believed that once the right raw materials were gathered, life might develop rather quickly. A century would be perhaps unreasonably brief, in his view, but if it didn’t happen in a million years, he reasoned it probably never would. Knowledge of the ingredients of Earth’s early atmosphere has since changed, but still today, Harvard paleontologist Andrew Knoll takes a similar view of time frame for things to get going. “I’d guess that the 10,000 to 1-million-year window is reasonable,” Knoll, a member the Mars rover science team, told “The other question, of course, is what it takes for life to persist on a planet. If water is present only intermittently, then any life that originates has little chance of surviving in the long run.”

Other research has suggested that water might have flooded the surface of Mars in hellish bursts. Nobody can say if that was the case, or if so then how many centuries or millennia the bursts might have lasted. And so far, Opportunity has not determined how long its Meridiani Planum landing site was wet, nor when in the past the rocks were drenched. Further observations from the twin rover mission could provide some clues to this crucial puzzle, however. “If water is present on the Martian surface for 100 years every 10 million years, that’s not very interesting for biology,” Knoll has said in the past. “If it’s present for 10 million years, that’s very interesting.”

Life underground
Even if biology got a foothold on ancient Mars, it is not clear if anything could have persevered long underground, with or without salty survival skills. On Earth, organisms do thrive deep underground — hundreds of feet below — without a single ray of sunshine. They live off chemical energy instead, like methane or hydrogen produced in chemical interactions between water and rock. Being a halophile, it should be noted, is not a condition for being an underground extremophile, as ultra-hardy microbes are collectively known. In fact one organism that might have done well on ancient Mars is desulfotomaculum, which uses sulfur as its energy source, said Benton Clark III, chief scientist of space exploration at Lockheed Martin and a member of the rover team. “It can form spores as well, so it can hibernate over these interim times on Mars between the warmer spells,” Clark said last week in discussing Opportunity’s discovery.

Ultimately desulfotomaculum could not have endured the high salt concentrations that Mancinelli describes. Yet on ancient Mars, the door of life might have been open to creatures of various eating habits and with differing survival schemes. One thing most researchers agree on: the Sun was probably not a prime energy source. Bruce Jakosky is a geologist at the University of Colorado, Boulder and director of its NASA-sponsored Center for Astrobiology. He helped pick the rover landing sites but has not been directly involved in the rover science explorations. Jakosky says it might have made little difference to the question of biology whether the Opportunity landing site was once a sea or just a location of copious ground water. He says the type of organism one might imagine finding at Mars would likely use geochemical sources of energy, rather than sunlight. “On Earth, we think that chemical sources of energy came first, followed by photosynthesis, which is a more complicated process,” Jakosky said. “Chemical energy is available from day one.”

What are the odds?
There could be a huge hitch in all this thinking. Scientists are currently debating whether underground terrestrial life is truly independent of sunlight, or if the chemistry of the surface — including photosynthesis and its products and byproducts — must filter down to make life possible below. “Do those things that [an organism is] surviving on have to be coupled to the surface?” Mancinelli wonders. “The jury is still out.” Knoll, the paleontologist, says many underground bacteria “actually eat buried organic matter and so are inexorably tied to surface photosynthesis, even if indirectly.” He also cautions that life in a subsurface realm might need to routinely get from one oasis to another as a planet changes over time. “You only have to break this chain once for the experiment to end,” Knoll says.

Terrestrial life has proven itself to be ubiquitous and resilient, able to essentially eat rocks if need be, or to eke out an existence under Arctic ice with only intermittently present films of liquid water. It can lay dormant for many thousands of years, awaiting the right environment to allow it to repair its cells and divide into new ones. But could the long-sought little green microbes have endured eons inside Mars? “Underground life is a possibility for Mars’ past and, with much longer odds, perhaps even its present,” Knoll figures. “But in the absence of abundant surface life, I would assign a fairly low probability for the present day persistence of such ecosystems.”

Frozen sea on Mars linked to elevated methane
by Kelly Young and Jenny Hogan / 23 February 2005

The discovery of a frozen sea on Mars has ignited a new debate on whether life existed on the Red Planet. Most intriguing is the claim that the atmosphere above the frozen ocean in the Elysium Planitia region may have elevated concentrations of methane. If true, it could suggest that primitive micro-organisms might even survive on Mars today, according to Jan-Peter Muller, at University College London, UK, and one of the team that found the frozen sea. The team, which was led by John Murray at the Open University, UK, analysed images taken by Europe’s Mars Express spacecraft. “If the ice is still there, then Elysium is the most likely place to find past or present life on Mars,” says Murray. He presented the findings at the 1st Mars Express Science Conference in Noordwijk, the Netherlands, on Monday. Immediately after his talk, Vittorio Formisano, chief scientist for Mars Express’s Planetary Fourier Spectrometer (PFS) which measures the composition of gases in the planet’s atmosphere, commented: “Elysium Planitia is indeed the region where we have seen the maximum of methane coming out of the surface.” On Earth, most of the methane in the atmosphere is produced by microbes living in the soil. Formisano thinks that life is the most likely explanation for methane in the Martian atmosphere, too.

No consensus
NASA planetary scientist Chris McKay, who was not part of the research group, agrees that the site is an important one in the search for life. “If these are really locations where there was an ice-covered ocean, I think this would be a very interesting place to drill for evidence of past life.” But McKay warns that scientists have yet to reach a consensus about the presence of a high level of methane on Mars. Estimates of the expected lifetime of the gas in the atmosphere are uncertain, and may be off by a factor of 10,000. It is also possible that what scientists think is methane may be something else entirely, he says. And other scientists note that finding water would not necessarily equate to past or present life. “I think it’s way too early to jump to conclusions,” says Kenneth Nealson, a geobiology professor at the University of Southern California, Los Angeles, US. “Water is required for life, but it in no way indicates that there is life.”

Isotopic signature
The observations by Mars Express’s PFS instrument indicate concentrations of about 10.5 parts per billion in the Elysium Planitia region. Even if it is more concentrated in that area, it could just as easily be a product of geological activity as microbial life, Nealson adds. Elysium Planitia is one of the major volcanic regions on Mars. “If you had the isotopic signature of the methane, you might be on firmer ground,” he says, as this could indicate if the methane was formed biologically. Formisano has also reported, in September 2004, that concentrations of water vapour near the Martian surface are two to three times higher along three regions near the equator, including Elysium Planitia, than at higher altitudes. Those concentrations also correspond to results from NASA’s Mars Odyssey spacecraft, which sniffed out hydrogen in the uppermost metre of Martian soil and rock.


A microorganism that produces methane as a byproduct of its metabolism. All known methanogens are both archaeans and obligate anaerobes, that is, they cannot live in the presence of oxygen. They are commonly found in wetlands, where they generate methane in the form of marsh gas, and in the guts of animals such as ruminants and humans, where they are responsible for flatulence. Some methanogens, described as hydrotropic, use carbon dioxide as a source of carbon and hydrogen as a source of energy. Some of the carbon dioxide reacts with, and is reduced by, hydrogen to produce methane. The methane is turn gives rise to a proton motive force across a membrane, which is used to generate ATP – a key source of cellular energy. Other methanogens, called acetotrophic, use acetate (CH3COO-) as a source of both carbon and energy. Still other methanogens exploit methylated compounds such as methylamines, methanol, and methanethiol as well. More than 50 species of methanogens have been identified, including a number that are extremophiles. Live methanogens were recovered from a core sample taken from 3 kilometers under Greenland by researchers from the University of California, Berkeley. Another study discovered methanogens in soil and vapor samples from the vicinity of the Mars Desert Research Station in Utah. These findings add weigh to speculation by some scientists that methanogens may be responsible for the methane that has been in detected in the atmosphere of Mars.

Methane rivers and rain shape Titan’s surface
by Stephen Battersby / 21 January 2005

Hills made of ice and rivers carved by liquid methane mark the surface of Saturn’s giant moon, reveal data from the Huygens probe. Scientists are now beginning to get a coherent picture of Titan after the probe landed there on 14 January. The coldest world that humanity has ever explored bears a strange resemblance to Earth, boasting hills, river systems, and mud flats. The probe survived an unexpectedly bumpy ride through the atmosphere of Titan but enjoyed a soft landing, settling several centimetres into the surface, Huygens’ scientists revealed at the European Space Agency’s headquarters in Paris on Friday.

They have now analysed many of the images returned by Huygens’ cameras. In one small region just 1 kilometre across, the camera team have combined images to get a 3D view of Titan’s ice hills. “We see a ridge system with a peak 100 metres tall,” says Marty Tomasko of the University of Arizona, US, and head of the Huygens imaging team. There is even a hint of how the hills are built: “In another region we see a white streaky pattern, evidence of water ice being extruded by the surface.” Dark channels cutting across this area are now clearly revealed as drainage systems. “We see a river system that flows down into a delta. There are also short, stubby channels indicative of springs flowing out of the hillsides,” says Tomasko.

Flammable world
Scientists speculated long ago that some kind of hydrocarbon liquids might flow on Titan. “We’ve learned that our speculation was really pretty good,” says Toby Owen, of the University of Hawaii, an expert on Titan’s atmosphere. They now know that the fluid that carved the moon’s rivers and channels is methane. Huygens’ chemical analyser saw that methane gas becomes more concentrated lower in Titan’s atmosphere, just like water vapour on Earth. After landing, Huygens’ gas chromatograph and mass spectrometer instrument saw methane concentrations jump by 30%. The gas was probably evaporated from the muddy soil by heat from the European Space Agency’s probe. “It means there’s methane near the surface,” says Owen, “Titan is a flammable world.” But all the oxygen is trapped in ice. “That’s a good thing, or Titan would have exploded a long time ago.” While there are many signs of liquid on Titan, there is none currently visible to Huygens. “Titan may be typical of arid regions of Earth like Arizona, where riverbeds are dry most of the time,” says Tomasko. “Perhaps there’s a wet season once a year. We just don’t know.”

Exotic materials
The mud may be a mixture of ice, sand, methane and complex organic molecules that form in the upper atmosphere. “This smog falls out of the atmosphere and settles on everything. Then methane rain comes, washes it off the ice ridges and into rivers, then out into a broad plain where the rain settles into the ground and dries up. We are seeing evidence of Earth-like processes but with very exotic materials,” says Tomasko. There are plenty of mysteries still to unravel. Methane is constantly being destroyed and turned into a complex chemical smog, so there must be some methane source inside Titan to replenish the atmosphere. And certain gases, including argon, are inexplicably absent from Titan’s atmosphere, which may be a clue to how the moon formed. However, Huygens has seen only one small patch of the surface – which might turn out to be unusual – it might even have come down in a desert. “This is one single place on an interesting and varied world,” says Owen. Jean-Pierre Lebreton, the Huygens mission manager hopes that the probe will inspire a new mission to Titan: “The next capability to bring to Titan is mobility. We can now seriously dream of sending rovers to its surface. Or flying machines, or balloons to float around the moon. We just need the money.”

Life on Titan ?

Over the past few years, the scientific community has realized that numerous forms of life evolve in extreme conditions on Earth.For instance, we found out bacteria being able to support temperatures up to 113°c and living in boiling water of thermal sources. We also found fishes living in the abyss of oceans and supporting pressures 500 times higher than the atmospheric pressure.Another example: the well known Yellowstone National Park ( USA ) is filled with billions of bacteria living in water whose temperature is around 70°c.

The intensive exploration of the most inhospitable places on Earth has shown that what we call now the extremophiles are capable of living without sunlight or oxygen.Where there is not much oxygen and no sunlight, one can encounter blind spiders or other insects with no pigment and being able to draw their energy from the mixture of hydrogen and sulfur released by volcanic chimneys.All those observations push us into thinking that any exotic life is a possibility in other hostile worlds like Europa,Titan or even Jupiter.

Titan seems to be a very hostile sphere, notably in terms of temperature.Our temperature model derived from the Stefan’s law shows that the surface temperature is expected to be around -114°c ( 159K or -173°F) on the basis of an atmospheric pressure of 1.5 bars.Hence, the atmosphere is likely to generate a greenhouse effect that increases the environmental temperature by about 74°c.It’s unsufficient to allow the presence of liquid water on the surface.Now, liquid water appears to be the essential solvent from which life has emerged.But, on Titan, contrary to the other bodies in the Solar System, a liquid of hydrocarbon ( ethane, methane…) or ammonia might be present at the surface, perhaps allowing the development of organic molecules, amino acids,proteins or DNA.It is often said that Titan puts together the ingredients of the primitive soup, the chemistry that led to life on Earth. A famous laboratory experiment was carried out in the 1950’s by Stanley Miller to try to figure out the secrets of the origin of life. He submitted a mixture of methane ( CH4), hydrogen ( H2), ammonia (NH3) and water vapour ( H2O) to electric sparks for many days in a closed system. The sparks were supposed to represent lightning in the early stages of our planet and the previous molecules were believed to represent the major components of the early Earth’s atmosphere.After several days of electric sparks, he obtained organic compounds ( HCN, HCHO…) and amino acids which are used to make proteins.Did this process occured on Titan? It’s hard to say but one thing is striking : the resemblance between Titan’s atmosphere and Earth’s atmosphere.The atmosphere of those two bodies is mostly composed of nitrogen ( 78% for Earth and around 90% for Titan ) contrary to Venus and Mars which are mostly composed of carbon dioxide.Nevertheless, Titan is very poor in oxygen meaning that there is no life breathing oxygen or using oxygen in the feeding process.

A form of life on Titan?
If there is life on Titan, what might it look like? An answer implies that we analyse the basis and the environment of life on Earth and that we try to imagine the elements of the Titan crust. On Earth, water acts not only as a solvent for the living creatures to combine, it is also the major compound of life herself.For instance, plants and jelly fishes have an abundance of water higher than 90% of their weight. Human beings are also mostly composed of water in a proportion of around 65%.To sum up, it is hard to conceive that life can be envisaged without the water molecule. Likewise, it is also hard to admit that we can encounter a form of life which is not based on the carbon element since it is present in large amounts in every species on Earth. Carbon is the second major constituent of life: it represents around 30% of the human weight and calcium, magnesium and other oligo elements are in a very small proportion. Another particularity of life is that it is always based on DNA ( Deoxyribo Nucleic Acid ) except that one knows one exception.The fact that water is the most common molecule on Earth leads us to say that life has emerged by using what was the most common molecule. However, carbon is relatively rare in our environment while it is abundant in every living creature. Carbon has chemical and physical properties that enable it to combine very well with oxygen, hydrogen or water which is less the case for Silicon. That is the reason why an element so rare in the crust of our planet has contributed to build the most complex molecular structures in nature.

On Titan, the most fundamental differences with Earth are the gravity and the distance to the Sun. Most scientists believe that there would be no life on Earth if the sphere were 5% farther from the Sun or 1% closer to the Sun.Too far from the Sun and the planet would be too cold for life to evolve and too close and our planet would resemble Venus. But Titan is so much different that the theories that apply to Earth may not work for Titan.Titan presents a major advantage of being protected from the noxious solar radiations by a very thick atmosphere largely denser than our own atmosphere.On this point, it is a less hostile environment for any living creature to evolve than Mars, for example.Nevertheless, as we’ve said, the temperature on Titan might be below -100°c erasing the probability of discovering liquid water in some place though thermal sources are likely to raise this possibility.With a solvent like ethane or methane, one can imagine a completely different chemistry of life from what we know.The species would not absorb oxygen like human beings or carbon dioxide like plants as carbon dioxide is frozen and oxygen is very rare.According to Marc Lafferre and Guilhem Cournot, one might encounter living creatures absorbing hydrocarbon gas ( methane, ethane…) which are relatively common in the atmosphere ( around 5% of the atmosphere’s composition) and releasing hydrogen which will recombine again with nitrogen or hydrocarbon molecules in the atmosphere to form other hydrocarbon molecules or ammonia under the action of ultraviolet light that splits the molecules.Hence we could see lakes or oceans of hydrocarbon ( ethane, methane…) with glaciers of ammonia rich ice resulting from a snow of ammonia falling from time to time.Living species would consist mostly of hydrocarbon ( methane…).So, the major elements of life would be carbon and hydrogen.The oxygen would be present in a smaller proportion in the structure of life because of the low environmental temperatures that favour combinations with carbon and hydrogen rather than hydrogen with oxygen or carbon with oxygen which are frozen on the surface of Titan ( frozen carbon dioxide and frozen water ).The french chemist André Brack in 1993 pointed out that a form of life based on silicon could be envisaged : the species would be mostly composed of silicon, an element very abundant in the soil ( around 25% of the composition of the crust on Earth ).In other words, the creatures would be made of sand.They would breathe oxygen or hydrogen and would release silicon dioxide ( Si O2 ) or Si H2. Silicon like carbon has the ability to create bonds simultaneously with four other elements and to give birth to multiple molecules. However, the bonds are particularly rigid compared to carbon.As a result, the species would be very limited and their development and adaptation capabilities would be slown down. The main advantage of this form of life would be to resist higher environmental temperatures.On Titan, the low temperatures diminish the probability of encountering this hypothetical form of life.On the other hand, Venus could have harboured that kind of life because of the very hot environmental temperatures.Furthermore, on Titan, a form of life involving the chemistry of nitrogen and ammonia appears less credible since carbon doesn’t play a key role in this configuration.

If the distance plays a crucial role for the appearance of life, the gravity of the saturnian moon plays a key role for the way life will develop and evolve.The low gravity of Titan allows creatures to be thinner with thin bones if they have bones.To sustain their own weight, they don’t need to have powerful legs or paws.The fish moves in a liquid less dense than water.So, he has no interest of being heavy and short according to the Archimedes’ Law. As said Ralph Lorenz, Titan is a heaven for hypothetical birds: they benefit from a low gravity and a thick air.They can be heavier than on Earth and their wings can be shorter which is also better in a cold environment.A denser air enables birds to carry out fewer movements of the wings to advance at the same speed.

It seems, today, that the environmental temperature on Titan is by far too cold to allow the development of an Earth like life, based on water and carbon.But the evolution of the Solar System and the Sun could become more and more favourable for the development of a life on Titan very soon.According to Chris Mc Kay,who studied notably the possibilities of terraforming on Mars,Titan might become warm enough, over the next five billion years, to host life. The Sun is expected to cool down very progressively and in a few billion years, it will become a red giant, a less energetic star, extending far beyond the orbit of our planet.As a result, it will be largely closer to Titan and the amount of energy received by the satellite, though less energetic, will be sufficient to raise the overall temperature so that water appears in its liquid form.Less ultraviolet light will attain the atmosphere of Titan so that the shield of red haze that resulted from the action of those particles and that prevented the light from reaching the soil will disappear and an Earth like meteorology will emerge.The current prebiotic molecules will then be able to combine and evolve towards the development of amino acids, proteins and life.

A model for methane based life
In this model developed by Marc Lafferre and Guilhem Cournot ( 2004 ), the mean temperature at the surface of the satellite is around -114°c ( -173°F or 159K). This temperature is well above the theoritical temperature thanks to a greenhouse effect that raises the temperature by about 73°c (163°F or 346K).This mean temperature is too high to allow the presence of liquid methane despite high pressures that delay the boiling point.On the other hand, seas and lakes of ethane rich hydrocarbon can be observed.Ethane ( C2H6 ) is in its liquid form between -88°c and -183°c.So, the evaporation process is weak. The atmosphere consists mostly of nitrogen and contains a large amount of one of the most powerful greenhouse gases one knows,that is to say methane ( CH4) which represents up to 5% of the atmosphere. The ultraviolet radiations from the Sun engender complex photochemical reactions in the upper atmosphere by breaking the methane molecules ( CH4) into various compounds such as acetylene ( C2H2) or Ethane (C2H6) which combine with other molecules to form tholin,a kind of red sludge.The ethane molecules formed in the upper atmosphere will then fall as rain in small quantities.

Under those circumstances, an ecosystem based on methane has emerged.The solvent that enabled life to develop on Earth, that is water, is replaced here by liquid hydrocarbon. The living creatures have not developed on the basis of water or carbon dioxide since both molecules are frozen at the surface of Titan. In other words, the species are not made up of water ( H2O ) contrary to life on Earth. The key compounds of life on Titan are carbon, hydrogen,methane and ethane.Those elements or molecules are more flexible and more volatile than oxygen and water in the harsh local climate conditions.The creatures absorb the hydrocarbon liquid as we absorb water and most of them, including plants, breathe the methane gas to produce the organic material and expire H2.The birds, for instance, drink “ethane rich hydrocarbon liquid”, breathe H2 released by plants and expire CH4.In a sense, that would be the biological cycle of methane.

As the solar energy reaching the Titan soil is very weak at this distance from the Sun, the forms of life prospering on Titan are less pigmented than on Earth.Obviously, we don’t encounter animals as colourful as the animals we can see in a tropical area on Earth. Finally, animals tend to have white or slightly red colours.They have developed a biological structure that enable them to store and manage the little energy they receive.Furthermore,they benefit from a low gravity: that’s the reason why the skeleton of Titan mammals is generally thinner than that of Earth’s mammals.Titan is a paradise for birds: they benefit not only from a low gravity, seven times smaller than on Earth, but also from a dense air which makes possible a smaller frequency in the movement of wings.Thereby, the bird spends less energy to fly though the air is heavier and more difficult to displace.

Hence, Titan appears to be a major source of speculation and research for exobiologists in their quest for the secrets of the origin of life.No doubt that the exploration of Titan will allow us to better understand the chemistry of every planet in the Solar System and perhaps the chemistry that led to life on Earth.

Electrical Activity On Saturn’s Moon Titan Confirmed By Spanish Scientists / July 29, 2008

Physicists from the University of Granada and University of Valencia have developed a procedure for analysing specific data sent by the Huygens probe from Titan, the largest of Saturn’s moons, “unequivocally” proving that there is natural electrical activity in its atmosphere. The scientific community believe that the probability of organic molecules, precursors of life, being formed is higher on planets or moons which have an atmosphere with electrical storms. The researcher, Juan Antonio Morente, from the Department of Applied Physics at the University of Granada, indicated to SINC that Titan has been considered a “unique world in the solar system” since 1908 when, the Spanish astronomer, José Comas y Solá, discovered that it had an atmosphere, something non-existent on other moons. “On this moon clouds with convective movements are formed and, therefore, static electrical fields and stormy conditions can be produced”, he explained. “This also considerably increases the possibility of organic and prebiotic molecules being formed, according to the theory of the Russian biochemist Alexander I. Oparín and the experiment of Stanley L. Miller”, which managed to synthesise organic compounds from inorganic compounds through electrical discharges. “That is why Titan has been one of the main objectives of the Cassini-Huygens joint mission of NASA and the European Space Agency”, added the researcher. Morente indicated that in order to detect natural electrical activity on planets such as Earth or moons such as Titan the so-called “Schumann resonances”, a set of spectrum peaks in the extremely low frequency (ELF) portion of the radio spectrum, are measured. These peaks are produced due to the existence between the ionosphere and the surface of a huge resonant cavity in which electromagnetic fields are confined. They present two basic components: a radial electrical field and a tangential magnetic field, accompanied by a weak tangential electrical field (one hundred times smaller than the radial component).

The electrical field was measured by the mutual impedance probe (MIP), one of the instruments transported by the Huygens probe. The MIP consisted of four electrodes, two transmitters and two receptors, with a transmitter-receptor pair on each one of the probe’s folding arms. The MIP was primarily used for measuring the atmosphere’s electrical conductivity, but between each measurement of this physical magnitude it also acted as a dipolar antenna, measuring the natural electrical field in the atmosphere. “In a stable fall, without balancing, the MIP would have measured the electrical field’s weak tangential component”, said Morente, “but fortunately a strong wind balanced the probe and the electrodes measured a superposition of that tangential and radial component”. Despite this, the electrical field spectrums received directly from Huygens did not follow the patterns the scientists expected, as they were relatively flat and no Schumann resonances were observed. However, the team of Spanish researchers did manage to devise a procedure for revealing the hidden Schumann resonances, based on the separation of time signals known as “early” and “late-time”, which made it possible to obtain “irrefutable proof” that natural electrical activity does exist in Titan’s atmosphere. In the work, subsidised by the former Ministry of Education and Science, Government of Andalusia and the European Union, it was also explained that the atmosphere of this one of Saturn’s moon is an electromagnetic medium with high losses, and that its resonant cavity is less ideal than the Earth’s.


In 1954, J. B. S. Haldane, speaking at the Symposium on the Origin of Life, suggested that an alternative biochemistry could be conceived in which water was replaced as a solvent by liquid ammonia.1 Part of his reasoning was based on the observation that water has a number of ammonia analogues. For example, the ammonia analogue of methanol, CH3OH, is methylamine, CH3NH2. Haldane theorized that it might be possible to build up the ammonia-based counterparts of complex substances, such as proteins and nucleic acids, and then make use of the fact that an entire class of organic compounds, the peptides, could exist without change in the ammonia system. The amide molecules, which substitute for the normal amino acids, could then undergo condensation to form polypeptides which would be almost identical in form to those found in terrestrial life-forms. This hypothesis, which was developed further by the British astronomer V. Axel Firsoff,2, 3 is of particular interest when considering the possibility of biological evolution on ammonia-rich worlds such as gas giants and their moons.

On the plus side, liquid ammonia does have some striking chemical similarities with water. There is a whole system of organic and inorganic chemistry that takes place in ammono, instead of aqueous, solution.4, 5 Ammonia has the further advantage of dissolving most organics as well as or better than water,6 and it has the unprecedented ability to dissolve many elemental metals, including sodium, magnesium, and aluminum, directly into solution; moreover, several other elements, such as iodine, sulfur, selenium, and phosphorus are also somewhat soluble in ammonia with minimal reaction. Each of these elements is important to life chemistry and the pathways of prebiotic synthesis. The objection is often raised that the liquidity range of liquid ammonia – 44°C at 1 atm pressure – is rather low for biology. But, as with water, raising the planetary surface pressure broadens the liquidity range. At 60 atm, for example, which is below the pressures available on Jupiter or Venus, ammonia boils at 98°C instead of -33°C, giving a liquidity range of 175°C. Ammonia-based life need not necessarily be low-temperature life!

Ammonia has a dielectric constant about ¼ that of water, making it a much poorer insulator. On the other hand, ammonia’s heat of fusion is higher, so it is relatively harder to freeze at the melting point. The specific heat of ammonia is slightly greater than that of water, and it is far less viscous (it is freer-flowing). The acid-base chemistry of liquid ammonia has been studied extensively, and it has proven to be almost as rich in detail as that of the water system. In many ways, as a solvent for life, ammonia is hardly inferior to water. Compelling analogues to the macromolecules of Earthly life may be designed in the ammonia system. However, an ammonia-based biochemistry might well develop along wholly different lines. There are probably as many different possibilities in carbon-ammonia as in carbon-water systems.7 The vital solvent of a living organism should be capable of dissociating into anions (negative ions) and cations (positive ions), which permits acid-base reactions to occur. In the ammonia solvent system, acids and bases are different than in the water system (acidity and basicity are defined relative to the medium in which they are dissolved). In the ammonia system, water, which reacts with liquid ammonia to yield the NH+ ion, would appear to be a strong acid – quite hostile to life. Ammono-life astronomers, eyeing our planet, would doubtless view Earth’s oceans as little more than vats of hot acid. Water and ammonia are not chemically identical: they are simply analogous. There will necessarily be many differences in the biochemical particulars. Molton suggested, for example, that ammonia-based life forms may use cesium and rubidium chlorides to regulate the electrical potential of cell membranes. These salts are more soluble in liquid ammonia than the potassium or sodium salts used by terrestrial life.8

On the down side, there are problems with the notion of ammonia as a basis for life. These center principally upon the fact that the heat of vaporization of ammonia is only half that of water and its surface tension only one third as much. Consequently, the hydrogen bonds that exist between ammonia molecule are much weaker than those in water so that ammonia would be less able to concentrate non-polar molecules through a hydrophobic effect. Lacking this ability, questions hang over how well ammonia could hold prebiotic molecules together sufficiently well to allow the formation of a self-reproducing system.9

1. Haldane, J. B. S. “The Origins of Life,” New Biology, 16, 12-27 (1954).
2. Firsoff, V. A. Life Beyond the Earth: A Study in Exobiology. New York: Basic Books (1963).
3. V. Axel Firsoff, “An Ammonia-Based Life,” Discovery 23, 36-42 (January, 1962).
4. Gerhart Jander, Hans Spandau, C. C. Addison; eds. Chemistry in Nonaqueous Ionizing Solvents. New York: John Wiley, Interscience (1966).
5. Smith, Herchel. Organic Reactions in Liquid Ammonia. New York: John Wiley, Interscience (1950).
6. Franklin, E. C., “The Ammonia System of Acids, Bases, and Salts,” American Chemical Journal, 47, 285 (1912).
7. Firsoff, V. A., “Possible Alternative Chemistries of Life,” Spaceflight, 7, 132-136, (July, 1965).
8. Molton, P. M., “Terrestrial Biochemistry in Perspective: Some Other Possibilities,” Spaceflight, 15, 134-144 (April 1073).
9. Feinberg, Gerald, and Shapiro, Robert. Life Beyond Earth: The Intelligent Earthling’s Guide to Life in the Universe. New York: William Morrow (1980).



All known life on Earth is built upon carbon and carbon-based compounds. Yet the possibility has been discussed that life elsewhere may have a different chemical foundation – one based on the element silicon.

Early speculation
In 1891, the German astrophysicist Julius Scheiner became perhaps the first person to speculate on the suitability of silicon as a basis for life. This idea was taken up by the British chemist James Emerson Reynolds who, in 1893, in his opening address to the British Association for the Advancement of Science,1 pointed out that the heat stability of silicon compounds might allow life to exist at very high temperatures (see thermophiles). In an 1894 article,2 drawing on Reynolds’s ideas and also those of Robert Ball,3 H. G. Wells wrote:

One is startled towards fantastic imaginings by such a suggestion: visions of silicon-aluminium organisms – why not silicon-aluminium men at once? – wandering through an atmosphere of gaseous sulphur, let us say, by the shores of a sea of liquid iron some thousand degrees or so above the temperature of a blast furnace.

Thirty years later, J. B. S. Haldane suggested that life might be found deep inside a planet based on partly molten silicates, the oxidation of iron perhaps providing it with energy.

Silicon biochemistry?
At first sight, silicon does look like a promising organic alternative to carbon. It is common in the universe and is also a p-block element of group IV, lying directly below carbon in the periodic table of elements, so that much of its basic chemistry is similar. For instance, just as carbon combines with four hydrogen atoms to form methane, CH4, silicon yields silane, SiH4. Silicates are analogs of carbonates, silicon chloroform of chloroform, and so on. Both elements form long chains, or polymers, in which they alternate with oxygen. In the simplest case, carbon-oxygen chains yield polyacetal, a plastic used in synthetic fibers, while from a backbone of alternating atoms of silicon and oxygen come polymeric silicones.

Conceivably, some strange life-forms might be built from silicone-like substances were it not for an apparently fatal flaw in silicon’s biological credentials. This is its powerful affinity for oxygen. When carbon is oxidized during the respiratory process of a terrestrial organism (see respiration), it becomes the gas carbon dioxide – a waste material that is easy for a creature to remove from its body. The oxidation of silicon, however, yields a solid because, immediately upon formation, silicon dioxide organizes itself into a lattice in which each silicon atom is surrounded by four oxygens. Disposing of such a substance would pose a major respiratory challenge.

Life-forms must also be able to collect, store, and utilize energy from their environment. In carbon-based biota, the basic energy storage compounds are carbohydrates in which the carbon atoms are linked by single bonds into a chain. A carbohydrate is oxidized to release energy (and the waste products water and carbon dioxide) in a series of controlled steps using enzymes. These enzymes are large, complex molecules (see proteins) which catalyze specific reactions because of their shape and “handedness.” A feature of carbon chemistry is that many of its compounds can take right and left forms, and it is this handedness, or chirality, that gives enzymes their ability to recognize and regulate a huge variety of processes in the body. Silicon’s failure to give rise to many compounds that display handedness makes it hard to see how it could serve as the basis for the many interconnected chains of reactions needed to support life.

The absence of silicon-based biology, or even silicon-based prebiotic chemicals, is also suggested by astronomical evidence. Wherever astronomers have looked – in meteorites, in comets, in the atmospheres of the giant planets, in the interstellar medium, and in the outer layers of cool stars – they have found molecules of oxidized silicon (silicon dioxide and silicates) but no substances such as silanes or silicones which might be the precursors of a silicon biochemistry.

Even so, it has been pointed out, silicon may have had a part to play in the origin of life on Earth. A curious fact is that terrestrial life-forms utilize exclusively right-handed carbohydrates and left-handed amino acids. One theory to account for this is that the first prebiotic carbon compounds formed in a pool of “primordial soup” on a silica surface having a certain handedness. This handedness of the silicon compound determined the preferred handedness of the carbon compounds now found in terrestrial life. An entirely different possibility is that of artificial life or intelligence with a significant silicon content.

Notwithstanding the gloomy prognosis from chemists, silicon-based life has flourished in the imaginary worlds of science fiction. In one of its earliest outings, Stanley Weisbaum’s A Martian Odyssey, the creature in question is half a million years old and moves once every ten minutes to deposit a brick – Weisbaum’s answer to one of the major problems facing siliceous life. As one of the watching scientists observes

Those bricks were its waste matter… We’re carbon, and our waste is carbon dioxide, and this thing is silicon, and its waste is silicon dioxide-silica. But silica is a solid, hence the bricks. And it builds itself in, and when it is covered, it moves over to a fresh place to start over.

1. Reynolds, J. E. Nature, 48, 477 (1893).
2. Wells, H. G. “Another Basis for Life,” Saturday Review, p. 676 (December 22, 1894).
3. Ball, R. S. W. “The Possibility of Life in Other Worlds,” Fortnightly Review, 62 (NS 56), 718 (1894).
4. Alison, A. “Possible Forms of Life,” Journal of the British Interplanetary Society, 21, 48 (1968)


Fake Mars Mission Befallen By Real Drama

The Mars Society is a group that prepares for man’s eventual exploration of Mars with simulations in the Utahan desert. But their mission logs, posted regularly on the group’s website, reveal a tension that is very real—and very funny. The two-week simulations, including various experiments and equipment tests, take place at the Mars Desert Research Station, located outside Hanksville, Utah. The volunteers who participate are expected to take the matter very seriously—after all, our future Mars colony depends on it. But of course, some pretend Mars astronauts are more dedicated than other pretend Mars astronauts and this is where the trouble starts. The current team occupying the Research Station, Crew 90, is led by Nancy Vermeulen. According to their “Mission Info” page, they are the first team comprised entirely of Belgians. In the wake of the trouble they’ve been having, it now seems ominous that the last line of their statement reads, “the media is following our project very closely.” Indeed, Geekosystem picked up on the mission and faithfully documented its simmering turmoil. After days of snits and snubs, the tension came to a head on February 15. In that day’s report, Commander Vermeulen explains:

“…The growing frustration that after 9 days PE, Nora and Margaux are still not able to manage the Hab systems/ standard engineering reporting system (and even don’t consider this as a problem!), exploded during the lunch. The lack of dedication to the mission of some people overloads the others and it had to be spoken out. The problem was already there from the first day, when it came out that some people didn’t prepare anything for the mission, didn’t look at the manuals, which were send to them months ago and didn’t even prepare the tasks for their own role. The accusation into my direction that I didn’t brief enough about the systems was too much. Nicky almost exploded. Arjan reacted double: At one hand he couldn’t stop criticising the incompetence of some others during last week, but during the discussion he acted as if he was from Barcelona (don’t know anything). He has his own mission and own world…”

The Commander’s Reports for the last days of the mission, which ended yesterday, obscure the interpersonal conflicts that paralyzed the crew. Only a few bloody noses are referenced, perhaps as physical manifestations of the crew’s frustrations.

What’s the point of a fake 500-day Mars mission?
BY Phil McKenna / 22 October 2009

The European Space Agency is seeking six volunteers to spend 520 days inside a sealed isolation facility to study the psychological effects of a journey to Mars. The 2010 Mars-500 “mission” at the Russian Institute of Biomedical Problems in Moscow will simulate a round trip to the Red Planet – albeit shorter than the real thing – and follows a similar 105-day study that ended in July. But does spending a year and a half locked inside a tin can on Earth tell us anything about how humans might behave on a high-risk interplanetary odyssey?

How much can Mars-500 be like the real thing?
Once inside the windowless isolation chamber, the team will mimic each stage of a Mars mission – including the journey, landing and return to Earth. A few aspects cannot be simulated, however. There will be no radiation exposure or zero gravity, and if there is a real emergency during the simulation, volunteers will have the right to get out at any time. A study by Peter Suedfeld of the University of British Columbia in Vancouver, Canada, argues that such experiments lack some key attributes of real long-haul space flight, such as dangerous voyages through unknown territory and the impossibility of rescue. Suedfeld concludes that mission planners would better identify the psychological stresses likely to be experienced by Mars explorers by reading the diaries of explorers on long expeditions over sea and land in previous centuries. Still, there are many things the Mars-500 experiment will reveal that historical records cannot. Volunteers will undergo an array of tests that will monitor stress and hormone levels, immune response and sleep patterns, as well as group dynamics.

What can we learn during 500 days that we can’t from 100?
The 105-day isolation study went off without a hitch, but crew members struggled with boredom and the stresses of a cramped environment. An experiment that lasts five times as long would better demonstrate how a crew would hold up for a 900-day Martian mission.

What other places could inform Mars mission planners?
Some behavioural scientists feel Antarctic research stations or nuclear submarines offer better analogies to prolonged space flight. But although Antarctic outposts have the necessary elements of danger, confinement and isolation, they lack the high level of automation found in space flight. Nuclear submarine control rooms are more like spacecraft, but military secrecy puts them off limits for academic research. A better model may be the experience of astronauts aboard space stations orbiting Earth. Their stays have lasted up to 438 days.

Can humans cope with prolonged space station missions?
By and large, space station missions have gone without incident. However, NASA astronauts on a three-month mission to Skylab in 1973 went on strike for a day saying they felt overworked and unsupported by their ground crew. In 1982, two Soviet cosmonauts spent most of a 211-day flight in silence because they got on each other’s nerves. Three years later, a six-month Soviet mission was cut short when a cosmonaut had a nervous breakdown. Sexual harassment could also endanger a mission. In an eight-month space station simulation in 2000, a man twice tried to kiss a woman against her will. As a result, locks were installed between different crew compartments. Astronauts in orbit often express feelings of neglect by ground crews, in part because of lags in communication and perhaps also because of a need by astronauts to take out their frustrations on others. As a result, ground crews as well as astronauts now receive psychological training.

Earthbound experiment to recreate stress of Mars mission
BY Kelly Young / April 2007

Scientists are being asked to submit research proposals for a 500-day-long study simulating a human mission to Mars. The programme, a joint project between Russia and the European Space Agency, would be the longest simulation of its kind. The 1.5-year Mars-500 simulation is designed to recreate some of the isolation and stresses that crew members might feel on an actual roundtrip to Mars, which would take about twice as long. In late 2008 or early 2009, six people will enter a mock spacecraft in Russia consisting of a series of connected metal tanks. The 200-square-metre ‘spacecraft’ will include a medical area, a research area, a crew compartment and a kitchen. The first leg of the experiment will last about 250 days and will simulate the journey to Mars. Then, part of the crew will enter a special Mars descent vehicle tank for 30 days to simulate a Mars landing. The entire crew will then make the return trip back to Earth. The Russian Academy of Sciences’ Institute of Biomedical Problems (IMBP) has already received more than 70 applications for the mission.

Frozen food
ESA will get to choose two crew members for the project, although it has not yet finalised its criteria. ESA scientists plan to start the selection process in June 2007 and pick the participants and the science experiments in October. During the 500-day study, the crew will try to live as a real crew headed to Mars might. At the beginning of the study, they will be given all the food they will ever get on the mission. That means they will largely subsist on frozen meals, though Russia might allow the crew to have a greenhouse to grow fresh produce. Their day-to-day lives will be similar to crew members on the International Space Station, except for the presence of gravity. They will have cleaning, cooking, maintenance and scientific duties. They may even have press conferences with real reporters. “The design will be such you start to forget it is a real simulation,” says Marc Heppener, ESA’s head of science and applications in the directorate of human spaceflight, microgravity and exploration. “People can be completely absorbed by games on the computer. You can go pretty far in a simulation.”

Communications delays
To make it even more realistic, there will be a 20-minute communications delay between people in the spacecraft and “mission control” to simulate the time lag faced by spacecraft far from Earth. The reactions of the “ground controllers” will also be studied. “Just imagine what would happen if you were on the phone and you hear on the other side, ‘Help!’ but you know this ‘Help!’ was uttered 20 minutes ago,” Heppener told New Scientist. “And if you say, ‘What can I do?’ it will be another 20 minutes before they hear you. That’s part of the psychology of this kind of study, and that’s absolutely not trivial.” Scientists might be able to learn how the crew reacts to minor emergencies, such as a water line breaking. As on a real extended space mission, it is likely that at least one crew member will have medical training. But if there is a real emergency during the simulation, “any person has the right to get out”, Heppener says. “However, we want to make sure this only happens in real emergencies.”

Bloody brawls
The extreme isolation and confinement of the simulation will lend important insights into how to design long-duration crewed space missions. “If I imagine myself where I really cannot see home, the planet where I live and where every other human being is, I can imagine that is quite significant,” Heppener says. Russia has conducted shorter simulations in the past and has seen firsthand the issues that arise, including sexual harassment. In an eight-month IMBP simulation in 2000, a Russian man twice tried to kiss a Canadian female researcher after two other Russians had gotten into a bloody brawl. As a result, locks were installed between the Russian and international crews’ quarters (see Out-of-this-world sex could jeopardise missions). The 500-day study will be preceded by one or two 100-day simulations to work out the early kinks. The first 100-day study could begin in early 2008. In conjunction with the Russian study, ESA is also seeking proposals for the French and Italian Concordia research station in Antarctica in the hopes of running two parallel studies in two different isolated settings.

Monotony was ‘most difficult part’ of simulated Mars trip
BY Rachel Courtland / July 2009

A group of volunteers that spent 105 days locked up in a mock spaceship simulating a trip to Mars is finishing up their final tests this week. The programme, which was used to test the psychological and physiological effects of isolation, will pave the way for a longer 520-day mission that will take place in the first half of 2010. Isolation has long been a part of human exploration, both on Earth and in space. But manned trips to Mars could be a challenge for even the most balanced and carefully selected crews, since the missions would involve small crews, tight quarters, years of separation from friends and family, and communications delays that could last up to 40 minutes. To investigate issues that would arise in such situations, the European Space Agency has partnered with the Russian Institute for Biomedical Problems in Moscow to arrange a 105-day simulated mission to Mars. The experiment took place in a multi-floored facility in Moscow that includes a mock spacecraft, a descent vehicle, and a simulation of the Martian surface. On 14 July, a crew of six emerged from the module. Although researchers are still analysing the results of the tests conducted during the simulation and performing follow-up tests on the participants this week, the mission seems to have finished largely without incident. “The most difficult part of the mission was not a single event but more the monotony,” says Oliver Knickel, a mechanical engineer in the German army and a volunteer for the 105-day mission.

Less focused
The bulk of the crew’s working day was occupied by psychological and physiological tests, Knickel told New Scientist. The crew ate astronaut-style pre-packaged meals that were intermittently enhanced by fresh vegetables like radishes and cabbage that the crew grew in a small greenhouse. In his off-time, Knickel passed the time by writing letters, learning Russian, and playing poker and dice with his crewmates. But the isolation and confinement in a cramped space did take its toll. “I had a hard time focusing on the things I was doing,” Knickel told New Scientist, adding that he did not retain newly learned Russian vocabulary words was well as he did back home.

Right chemistry
Crew compatibility is important for the success of future Mars missions. “You have a crew that has to live together and function as a team for a long period of time, and they really can’t leave that environment,” says Jay Buckey, a doctor and former astronaut at Dartmouth University in Hanover, New Hampshire. Participant Cyrille Fournier, an airline pilot from France, says there was a good sense of camaraderie over the 3.5 months the six volunteers spent together. “We had an outstanding team spirit throughout the entire 105 days,” he said in a statement. “Living for that long in a confined environment can only work if the crew is really getting along with each other. The crew is the crucial key to mission success, which became very evident to me during the 105 days.”

Self-directed mission
During the mission, the crew had to respond to simulated emergencies and deal with a communication delay of up to 20 minutes each way when talking to ‘ground controllers’ – mimicking the time it takes for radio signals to travel between a Mars-bound spacecraft and Earth. Such communication lags mean that crews would not be able to respond in real-time to commands from the ground and would probably need to function fairly autonomously. Nick Kanas, a psychiatrist at the University of California in San Francisco, and colleagues used a month in the 105-day experiment to examine what happens when crews are given more freedom to devise their own schedules in order to meet a mission’s overarching goals. This increased autonomy has also been tested in the Haughton-Mars Project in the Canadian Arctic (see What is it like to live in isolation for months on end?) and at an underwater facility called Aquarius off the coast of Florida. In the future, Kanas hopes to perform a similar experiment aboard the International Space Station.

Safe environment
Isolation studies on Earth allow researchers to set up carefully controlled experiments, but they do have a downside. “Ground missions don’t really capture the danger in the space environment. If someone does want to quit, they can just knock on the door and be let out,” Kanas told New Scientist. Not so on a future trip to Mars, says Kanas: “There’s no possibility of support in case of a medical or psychological emergency. You’re really on your own.” To deal with such issues, other researchers, including Buckey, are developing software that would allow astronauts on long missions to act as their own counsellors and conflict negotiators.

In space no one else can hear you scream at each other
BY Hazel Muir / 14 March 2006

It’s the moment every wannabe astronaut dreams of: landing on Mars. Just imagine making that momentous speech as you plant your flag in the red soil, the sun rising behind you over Olympus Mons. Perhaps you’ll find fame as the discoverer of the first subtle signs of alien life. How breathtaking to see the Earth rise in the night sky, just a white dot among millions of others. But there is a flip side. By the time you make that speech, you will have been cooped up inside a metal box for six months. You’ll not talk to your friends or family for another two years. You and your fellow inmates are bound to have survived some hair-raising, potentially fatal crises, and everyone’s nerves will be in tatters. The pilot won’t talk to the engineer. And if that geologist looks at you and rolls his eyes one more time, you’ll punch his lights out. Despite the exciting goals, a crewed mission to Mars would mean enormous psychological stress. Seeing Earth as an anonymous dot could leave you with a profound sense of isolation, according to former astronaut Carl Walz, who spent more than six consecutive months on the International Space Station (ISS). “The impact of not being able to see the Earth while you’re in space is a big deal,” he says. Until we leave Earth far behind, we won’t really know the effects of that.

NASA’s plans for a crewed mission to Mars sometime after 2020 are hugely ambitious. The spacecraft would take four to six months to reach the planet. After 18 months on the surface, the astronauts would take another four to six months to return to Earth, making it by far the longest space mission ever undertaken. NASA will have a tough job on its hands building a spacecraft capable of getting to the Red Planet and back, as well as finding ways to keep the astronauts in good physical shape during such a mammoth trip. The psychological challenges are no less daunting, though psychologists are now beginning to understand what keeps astronauts happy and mentally healthy. “We’ve started to learn a lot about how people really behave in space,” says Nick Kanas, a psychiatrist at the University of California and the Department of Veterans Affairs Medical Center in San Francisco. “I think we now have some knowledge that we could use to prepare astronauts for a Mars mission.”

NASA has already seen how conflict between astronauts and ground crew can escalate. Feeling overworked and unsupported, astronauts on a three-month mission to the Skylab station in 1973 went on strike for a day. They eventually cleared the air after a heated argument. But such mutinies could be potentially disastrous, especially if they were to happen during some kind of crisis, if the spacecraft went out of control, for example. To head off the possibility of further rebellions, Kanas and his team have spent the past 10 years studying the behaviour of astronauts who spent up to seven months on the now defunct Russian space station Mir, or on the ISS. Eight Russian cosmonauts and five American astronauts took part on Mir, along with four three-person crews and three two-person crews on the ISS, which celebrated its fifth anniversary of continuous habitation in November. Nearly 130 American and Russian mission controllers were involved as well.

During the missions, astronauts and ground controllers completed a weekly questionnaire composed of questions from three standard psychological tests to assess mood, crew interactions and working environment. Given a list of adjectives like “gloomy”, “energetic” and “resentful”, for instance, they would give a score for how strongly they felt that particular emotion. Other questions measured factors such as their views of the group’s cohesiveness and levels of job satisfaction. Kanas’s team was surprised by the crews’ answers. They had expected to see astronauts’ morale decline during the second half of each mission. Psychologists have seen this effect in small isolated groups in Antarctica, when morale would often plummet after the mid-point of the stay, regardless of whether it was five or eight months. “People realise they’ve finally made it to the half-way point, but then it dawns on them that they have a whole other half to go,” says Kanas. “After that, they tend to report increased tension, homesickness and depression, and a drop in the cohesion of the group.” In extreme cases, people become fiercely territorial, so that minor intrusions like borrowing someone’s pen or sitting in “their” chair can ignite a brawl.

But this did not happen on Mir or the ISS. Kanas’s study suggests that astronauts’ morale stays pretty steady unless unusually stressful events occur. “Our subjects did react to events such as a fire or a problem with the oxygen generator,” says Kanas, who reported the results in October at the 56th International Astronautical Congress in Fukuoka, Japan. “In that week, they had slightly more negative emotions than usual. But their morale returned to baseline a week later.” Kanas says the likely reason for the astronauts’ level mood is that ground crew intervene to help astronauts deal with stress and boredom. On Mir, if psychologists sensed that a crew member was feeling low, they would schedule family chats, for instance. Supply missions from Earth also brought the Mir and ISS crews surprises and treats – their favourite foods, or letters and knick-knacks from family and friends – which always perked them up.

But one persistent problem did crop up for both Mir and the ISS. Crew members who reported tension and stress also tended to feel, as the Skylab astronauts did in 1973, that ground control were not supporting them enough – even when there was no clear evidence for this. It is commonly known as “displacement”. “It’s just like when you have a tough day at work,” says Kanas. “Maybe your boss yells at you and you can’t yell back, so you go home and yell at your husband or kick the cat. You displace the anger you’re feeling onto somebody not related.” Frequent, frank communication can help prevent these problems festering. But that’s not going to be easy on a voyage to the Red Planet. Mars lies anything from 3 to 22 light minutes away from the Earth, depending on the orientation of the planets. So to say “hello” and get a reply will take up to three-quarters of an hour. There’s no way around that. Communication will be by email only.

And there won’t be any morale-boosting treats. NASA is considering sending a pod of supplies to arrive on the Martian surface ahead of the crew, but that will be about it. One possibility, though, is that the mother ship could have little compartments with surprises locked inside, and the ground crew could email codes to the astronauts to unlock them. “That is a very good idea because it’s an extension of the kinds of supportive activities we think have worked,” says Kanas. Nonetheless, he says, there will be a high risk of so-called adjustment reactions occurring as the mission drags on. Full-blown psychoses such as schizophrenia, paranoia and hallucinations have not been reported on space missions – not overtly, anyway – probably because potential astronauts with a family history of such problems are unlikely to make it past the selection process. But astronauts can become anxious and depressed, or suffer anxiety-induced psychosomatic ailments. Legend has it that one Russian mission was terminated early because a crew member had anxiety-induced heart palpitations.

These problems can only get worse on a trip to Mars. Isolation might seem overpowering to them as the Earth shrinks to a tiny dot among millions of others in the inky black sky. And there will be no quick escape route. “If someone gets depressed or suicidal, you can’t send them back very easily,” says Kanas. For this reason, he says it will be essential for the crew to have access to psychoactive drugs and to multitask. For example, the first mission will probably consist of six crew, including a pilot, an engineer, a biologist and a geologist. The other two might be a physicist and a doctor – should the doctor get sick, for instance, the biologist may be able to act in his or her place. It is the make-up and functioning of the group as a whole that interests Rachael Eggins, a psychologist at the Australian National University in Canberra. Since 2002, she and her colleagues have been monitoring volunteers at Mars simulation stations funded by the US Mars Society and the Mars Society of Australia.

The centrepiece of each station in the Utah desert and in the outback in Southern Australia, is an 8-metre-wide cylindrical habitat, or hab. Crews of four to six volunteers – mainly scientists and engineers, including many astronaut-wannabes – live there typically for two or three weeks. They live and work as if they were on Mars, testing reconnaissance robots and collecting rocks in mock spacesuits. They also send reports to a simulated “mission control” in a nearby city or support organisation. During Eggins’s studies, the volunteers completed questionnaires to assess their interactions with others. This revealed that people tend to cluster into cliques that often put their own goals ahead of the whole mission’s objectives. This led to a mishap in a Utah simulation in 2003, when the group split into three teams. One stayed in the hab, and two went out on separate rover trips, returning at about the same time. One person in the second rover damaged his helmet and was theoretically leaking oxygen. “It was obvious to everybody that in theory, if this was really Mars, then this guy would die,” says Eggins. However, the first team insisted on getting into the hab first and told the others to wait their turn, she says: “The first team were not thinking at all in terms of the overall goal of the mission, just of their own rights and the distinct subgroup.”

In another Utah simulation last summer, Eggins’s colleague Sheryl Bishop of the University of Texas in Galveston studied the differences between an all-male crew, who lived in the hab for two weeks, and an all-female crew who moved in for the following fortnight. Both teams performed well and were very productive, but they did differ. Personality surveys showed that several of the men scored low on “agreeableness” and “conscientiousness”, and the group’s behaviour echoed this. Every night, the women filed daily reports to mission control by the agreed time. But the men were persistently late. They said they preferred to use the time to explore outside on the buggies.

Cabin fever
And while the leader of the men’s team emailed the women’s team to say that they would give up the sleeping quarters for the handover night when the women arrived, some men were reluctant to do so. They had made a pact to hold out. “The men’s team had far more individualistic personalities, with a greater degree of concern for personal priorities,” says Bishop, who announced the preliminary findings at October’s International Astronautical Congress in Fukuoka. Bishop stresses that you cannot generalise from these results because the groups were too small and their membership was uncontrolled. It would also be absurd to compare risk-free fortnightly forays into the Utah desert to the trials of a three-year mission to Mars, when mistakes and communication breakdowns could be fatal.

The psychologists do say that such simulations can nonetheless highlight problems that might crop up. Many issues grow into confrontation within weeks, and psychologists can test their own abilities to detect conflicts in the making. They can also measure the success of interventions like psychological training, or changing the group compositions, leadership structures or environment. “If we see things that are problematical in small groups of short duration, you can bet those issues will be even more problematical for longer duration missions,” says Bishop. “Our teams to Mars had better be getting along very well indeed before we put them into a rocket for launch.”

Kanas says the most useful test of potential Martian astronauts will be to watch them in training – ideally on the ISS and possibly the moon, where NASA intends to send astronauts from 2015. “You could put the astronauts selected for Mars on the space station for a while and see how they get along in microgravity, which would model the trip out to Mars and back,” he says. “Then you could put them on the moon and totally isolate them in a foreign environment with no oxygen outside and partial gravity. That would be a good model for being on the Martian surface.” He also thinks it is vital to give the Martian astronauts and their ground controllers rigorous psychological training. Kanas has explained issues like the displacement problem on Mir to astronauts bound for the ISS. When they got back from the stay, some astronauts said this knowledge helped them to spot the problem developing and to nip it in the bud.

Kanas will test-drive more formal psychological training during future missions to the ISS. He and his colleagues will sit down with astronauts and their ground controllers prior to the launch to discuss the social and psychological pitfalls. Shortly after their arrival on the station, and half-way through the mission, a 30-minute computer session will give the astronauts a “booster shot”, reminding them what they learned. Questionnaires and post-flight interviews should reveal which aspects of the training are helpful. “This is my chance to apply directly what we’ve learned,” says Kanas. He thinks that with enough forethought given to their wellbeing, the Martian crew could be as happy as Larry. After all, happiness is relative. His studies show that on average, astronauts have lower scores for negative emotions like anxiety and depression than their colleagues back in mission control. The ground controllers in turn are more positive than the rest of us, in our offices, shops and factories. Perhaps space cadets could teach us all a thing or two.

Volunteers line up for simulated mission to Mars
BY Kelly Young / August 2006

More than 70 people have volunteered to be confined in a mock mission to Mars – for 520 days. It would be the longest simulation of its kind. The Institute of Medical and Biological Problems (IMBP) in Russia is undertaking the isolation study to learn more about the personal dynamics of long-duration space travel, according to Russian media reports. An actual round-trip mission to Mars could last about 30 months – about twice as long as this simulation. Five people will be eventually be selected for the study. They will spend 250 days on a simulated space trip to Mars. Then, three of the five will leave the mock spaceship for a simulated “landing on Mars” that will last 30 days. The five participants will then embark on a 240-day journey “back to Earth”. They will communicate with mission control by email. Russia and the European Space Agency have done space isolation studies before. In these studies, researchers accurately reproduce the interior environment of a spaceship and the length of time crews would spend in space.

Sex and violence
And the outcomes have not always been pleasant. In an eight-month simulation carried out by the IMBP in 2000, a Russian man twice tried to kiss a Canadian female researcher after two other Russians had gotten into a bloody brawl. As a result, locks were subsequently installed between the Russian and international crews’ compartments. Despite such conflicts, simulations of this type can lack a sense of danger, which is critical to understanding how people respond emotionally, says David Musson, a behavioural scientist at McMaster University in Hamilton, Canada. He says working in Antarctica and in submarines may provide better models of the long-term isolation experienced in space. “An Antarctic shack doesn’t look as much like a space station,” Musson told New Scientist. “But the isolation is more real, and the danger is more real.”

Subject selection
The simulations may also lack some of the appeal that draws people to spaceflight, so researchers may end up studying a different group of people than those who would actually fly on a space mission, he says. The IMBP has tried to minimise this issue by using cosmonauts and astronaut candidates in the past. And they are giving preference in this simulation to applicants who are doctors, biologists and engineers between the ages of 25 and 50. But Musson says a long-duration space mission may take a different type of astronaut than those who go on shorter trips to space. He points out that on the International Space Station and on Russia’s former Mir space station, some of the go-getter astronauts with multiple academic degrees found themselves bored by some of the mundane tasks onboard. Musson says someone with a more laidback personality might be better suited for a long-duration mission to Mars. These would be “mystery book [readers] who are quite happy not being pushed to their mental limit every day but are extremely bright and competent”.

Cultural differences
When planning a study like this, Musson says psychologists tend to want to see people with conflicting personalities while the politicians and organisers of the project just want things to go smoothly. So far, the IMBP reports it has received applications from 16 nations. An international crew should make the simulation more realistic, as it sets up an environment for potential conflict and misunderstandings due to cultural and linguistic differences. Jack Stuster, vice president and principal scientist of Anacapa Sciences in Santa Barbara, California, US, says realistic simulations are useful for understanding the interpersonal dynamics of long-duration spaceflight. “I believe that simulations of the duration mentioned will eventually be necessary preparation for planetary exploration,” he told New Scientist.



How Do You Get Plants To Grow On Mars? Relieve Their Anxiety / Aug. 8, 2005

Anxiety can be a good thing. It alerts you that something may be wrong, that danger may be close. It helps initiate signals that get you ready to act. But, while an occasional bit of anxiety can save your life, constant anxiety causes great harm. The hormones that yank your body to high alert also damage your brain, your immune system and more if they flood through your body all the time. Plants don’t get anxious in the same way that humans do. But they do suffer from stress, and they deal with it in much the same way. They produce a chemical signal — superoxide (O2-) — that puts the rest of the plant on high alert. Superoxide, however, is toxic; too much of it will end up harming the plant.

This could be a problem for plants on Mars. According to the Vision for Space Exploration, humans will visit and explore Mars in the decades ahead. Inevitably, they’ll want to take plants with them. Plants provide food, oxygen, companionship and a patch of green far from home. On Mars, plants would have to tolerate conditions that usually cause them a great deal of stress — severe cold, drought, low air pressure, soils that they didn’t evolve for. But plant physiologist Wendy Boss and microbiologist Amy Grunden of North Carolina State University believe they can develop plants that can live in these conditions. Their work is supported by the NASA Institute for Advanced Concepts.

Stress management is key: Oddly, there are already Earth creatures that thrive in Mars-like conditions. They’re not plants, though. They’re some of Earth’s earliest life forms–ancient microbes that live at the bottom of the ocean, or deep within Arctic ice. Boss and Grunden hope to produce Mars-friendly plants by borrowing genes from these extreme-loving microbes. And the first genes they’re taking are those that will strengthen the plants’ ability to deal with stress. Ordinary plants already possess a way to detoxify superoxide, but the researchers believe that a microbe known as Pyrococcus furiosus uses one that may work better. P. furiosus lives in a superheated vent at the bottom of the ocean, but periodically it gets spewed out into cold sea water. So, unlike the detoxification pathways in plants, the ones in P. furiosus function over an astonishing 100+ degree Celsius range in temperature. That’s a swing that could match what plants experience in a greenhouse on Mars.

The researchers have already introduced a P. furiosus gene into a small, fast-growing plant known as arabidopsis. “We have our first little seedlings,” says Boss. “We’ll grow them up and collect seeds to produce a second and then a third generation.” In about one and a half to two years, they hope to have plants that each have two copies of the new genes. At that point they’ll be able to study how the genes perform: whether they produce functional enzymes, whether they do indeed help the plant survive, or whether they hurt it in some way, instead. Eventually, they hope to pluck genes from other extremophile microbes — genes that will enable the plants to withstand drought, cold, low air pressure, and so on.

The goal, of course, is not to develop plants that can merely survive Martian conditions. To be truly useful, the plants will need to thrive: to produce crops, to recycle wastes, and so on. “What you want in a greenhouse on Mars,” says Boss, “is something that will grow and be robust in a marginal environment.” In stressful conditions, notes Grunden, plants often partially shut down. They stop growing and reproducing, and instead focus their efforts on staying alive–and nothing more. By inserting microbial genes into the plants, Boss and Grunden hope to change that. “By using genes from other sources,” explains Grunden, “you’re tricking the plant, because it can’t regulate those genes the way it would regulate its own. We’re hoping to [short-circuit] the plant’s ability to shut down its own metabolism in response to stress.”

If Boss and Grunden are successful, their work could make a huge difference to humans living in marginal environments here on Earth. In many third-world countries, says Boss, “extending the crop a week or two when the drought comes could give you the final harvest you need to last through winter. If we could increase drought resistance, or cold tolerance, and extend the growing season, that could make a big difference in the lives of a lot of people.” Their project is a long-term one, emphasize the scientists. “It’ll be a year and a half before we actually have [the first gene] in a plant that we can test,” points out Grunden. It’ll be even longer before there’s a cold- and drought-loving tomato plant on Mars–or even in North Dakota. But Grunden and Boss remain convinced they will succeed. “There’s a treasure trove of extremophiles out there,” says Grunden. “So if one doesn’t work, you can just go on to the next organism that produces a slightly different variant of what you want.” Boss agrees: “Amy’s right. It is a treasure trove. And it’s just so exciting.”

Wendy Boss
email : wendy_boss [at] ncsu [dot] edu

Amy M. Grunden
email : amy_grunden [at] ncsu [dot] edu


Plants and animals are fragile life forms. Dry them out, freeze them, expose them to high doses of radiation – they don’t do so well. But not all organisms are so picky. Many archaeans, for example, are distinguished by their ability to adapt to a variety of extreme environments. It’s in their genes. Archaeans are single-celled organisms. Under a microscope they look like bacteria. But genetically they’re as different from bacteria as you are. May of them are also extremophiles. They thrive under conditions that, until the 1970s, biologists thought were completely inhospitable to life. How do they do it? With a kind of genetic band-aid. Their DNA produces chemicals (enzymes) that repair the cell damage caused by environmental stresses.

There are plenty of harsh environments for life here on Earth. But when it comes to environmental stress, Mars has a corner on the market. The average temperature on the martian surface is about -63 C (-81 F); the atmosphere is a mere wisp of a thing, some 100 times thinner than Earth’s; the planet is dry as a bone; and the surface is bathed in damaging ultraviolet radiation. Some day humans will travel to Mars. Not only will they have to protect themselves from Mars’ harsh conditions, they’ll need to protect the food they grow, as well. The obvious solution would be to build greenhouses that provide Earth-like growing conditions. But that would require a tremendous expenditure of precious energy resources. Another solution would to modify the plants so that they grow under martian conditions.

That’s the challenge that Amy Grunden, an assistant professor of microbiology, and Wendy Boss, a botany professor, both at North Carolina State University, have set for themselves. They want to find out whether, by inserting genes from extremophile archaeans into plants, they can teach the plants to resist stress the way the archaeans do. Plant cells respond to stressors like cold or dehydration by creating a burst of superoxide, a toxic form of oxygen. Making poison may seem like an odd way to handle stress, but, explains Boss, “It’s a signaling mechanism. You get a small burst of reactive oxygen that tells the cell, Look, mount a defense, fight.'” But that can’t last forever. “Plants can lose a few cells and it doesn’t bother them,” says Boss. But if the stress – and the toxic oxygen – continues, “eventually the whole plant will die.”

Extremophile archaeans have found a way to deal with oxidative stress. They produce antioxidants. Through a series of chemical reactions, they turn superoxide into a more benign substance: water. These chemical reactions are initiated by enzymes, and the instructions for creating these enzymes are encoded in the organisms’ DNA. One organism capable of performing this feat is Pyrococcus furiosus, which makes its home in the boiling waters of deep-sea hydrothermal vents. Given its super-hot environment you might think that Pyrococcus furiosus is constantly producing antioxidants. But actually, when the organism is basking in the heat of the vent, there’s no oxygen present. It’s when cells get spewed out into cold sea water, where oxygen is present, that the antioxidant action takes place. “It’s been adapted to deal with oxygen at low temperature because that’s when it sees it, when it gets in the cold sea water,” says Grunden.

Several different enzymes are required to convert superoxide to water. What Grunden and Boss have been working on is injecting the genes that produce these enzymes into plants – actually, into a clump of tobacco cells in a Petri dish. So far, they have succeeded in transferring the gene that performs the first step in the detoxifying process; it produces the enzyme that converts superoxide to the less-toxic hydrogen peroxide. The tobacco cells not only survived the “invasion,” they produced the desired enzyme. Boss and Grunden are now in the process of adding a second gene, which produces an enzyme that converts hydrogen peroxide to water.

The entire archaeal stress-reduction process involves a total of four genes. The researchers plan to work their way up to this four-gene cocktail, one gene at a time. Then they’re going to try adding a gene from a bacterium, Colwellia psychrerythraea, which thrives at temperatures below freezing. Their goal is to produce a plant that can withstand the stress of freezing temperatures. “What we’re doing with having introduced the Pyrococcus gene is laying the foundation for being able to get over the initial shock of the extreme conditions. Now what we need to do is start adapting the plant to deal with the cold temperature conditions that you see on Mars,” says Grunden. Eventually, they hope to add genes for surviving under low-pressure and low-water conditions as well. “The Mars environment represents a multiple-stress condition.”

No-one has ever tried to do this before. And it may not work. “We may find that when we put the whole pathway in, the cell just drops dead like that, because it doesn’t like all these foreign genes,” Boss says. And then there’s always the danger that these modified plants, if they got released into the wild, could have a negative impact on forest land or crops. Boss counters that their experiments are being kept strictly under lab-safe conditions. “We are not intending to put them out in the public,” she says. “Nothing is escaping.” But Boss also sees potential benefit of the work that she and Grunden are doing. Eventually, she says, their experiments may result in crops that can “grow on poor soil with low water.” Such crops might, for example. help people survive a drought. “I really hope that this in four years will have a positive impact on agriculture, maybe even human health. Who knows? Maybe we can grow something from archaea in plants that will cure some disease.… There’s just so much biology that’s untapped out there. And these archaea make some interesting compounds. Maybe we need more of them.”

“a robotic greenhouse concept that is specially designed to help the future exploration and expanding population in the Mars. This intelligent robot can carry and take well care of a plant inside its glass container, which is functionally mounted on its four-legged pod. The robot is designed to learn the optimal process of searching for nutrients in order to keep the plant in a good condition. Moreover, it can send reports of its movements and developments to its fellow greenhouse robots through wireless communication, making it possible to learn from each other.”

Could Robotic Ants Build Homes On Mars Before We Arrive? / Oct. 27, 2008

Recent discoveries of water and Earth-like soil on Mars have set imaginations running wild that human beings may one day colonise the Red Planet. However, the first inhabitants might not be human in form at all, but rather swarms of tiny robots. “Small robots that are able to work together could explore the planet. We now know there is water and dust so all they would need is some sort of glue to start building structures, such as homes for human scientists,” says Marc Szymanski, a robotics researcher at the University of Karlsruhe in Germany. Szymanski is part of a team of European researchers developing tiny autonomous robots that can co-operate to perform different tasks, much like termites, ants or bees forage collaboratively for food, build nests and work together for the greater good of the colony. Working in the EU-funded I-SWARM project, the team created a 100-strong posse of centimetre-scale robots and made considerable progress toward building swarms of ant-sized micro-bots. Several of the researchers have since gone on to work on creating swarms of robots that are able to reconfigure themselves and assemble autonomously into larger robots in order to perform different tasks. Their work is being continued in the Symbrion and Replicator projects that are funded under the EU’s Seventh Framework Programme.

Planet exploration and colonisation are just some of a seemingly endless range of potential applications for robots that can work together, adjusting their duties depending on the obstacles they face, changes in their environment and the swarm’s needs. “Robot swarms are particularly useful in situations where you need high redundancy. If one robot malfunctions or is damaged it does not cause the mission to fail because another robot simply steps in to fill its place,” Szymanski explains. That is not only useful in space or in deep-water environments, but also while carrying out repairs inside machinery, cleaning up pollution or even carrying out tests and applying treatments inside the human body – just some of the potential applications envisioned for miniature robotics technology.

Creating collective perception
Putting swarming robots to use in a real-world environment is still, like the vision of colonising Mars, some way off. Nonetheless, the I-SWARM team did forge ahead in building robots that come close to resembling a programmable ant. Just as ants may observe what other ants nearby are doing, follow a specific individual, or leave behind a chemical trail in order to transmit information to the colony, the I-SWARM team’s robots are able to communicate with each other and sense their environment. The result is a kind of collective perception. The robots use infrared to communicate, with each signalling another close by until the entire swarm is informed. When one encounters an obstacle, for example, it would signal others to encircle it and help move it out of the way.

A group of robots that the project team called Jasmine, which are a little bigger than a two-euro coin, use wheels to move around, while the smallest I-SWARM robots, measuring just three millimetres in length, move by vibration. The I-SWARM robots draw power from a tiny solar cell, and the Jasmine machines have a battery. “Power is a big issue. The more complex the task, the more energy is required. A robot that needs to lift something [uses] powerful motors and these need lots of energy,” Szymanski notes, pointing to one of several challenges the team have encountered. Processing power is another issue. The project had to develop special algorithms to control the millimetre-scale robots, taking into account the limited capabilities of the tiny machine’s onboard processor: just eight kilobytes of program memory and two kilobytes of RAM, around a million times less than most PCs.

Tests proved that the diminutive robots were able to interact, though the project partners were unable to meet their goal of producing a thousand of them in what would have constituted the largest swarm of the smallest autonomous robots ever created anywhere in the world. Nonetheless, Szymanski is confident that the team is close to being able to mass produce the tiny robots, which can be made much like computer chips out of flexible printed circuit boards and then folded into shape. “They’re kind of like miniature origami,” he says. Simple, mass production would ensure that the robots are relatively cheap to manufacture. Researchers would therefore not have to worry if one gets lost in the Martian soil. The I-SWARM project received funding under the EU’s Sixth Framework Programme for research.

Marc Szymanski
email : szymanski [at] ira.uka [dot] de


The US space agency needs your help to explore Mars. A Nasa website called “Be A Martian” allows users to play games while at the same time sorting through hundreds of thousands of images of the Red Planet. The number of pictures returned by spacecraft since the 1960s is now so big that scientists cannot hope to study them all by themselves. The agency believes that by engaging the public in the analysis as well, many more discoveries will be made. The new citizen-science website went live on Tuesday at The site is just the latest to use crowdsourcing as a tool to do science. Players at Be A Martian can earn points in one game by helping Nasa examine and organize the images into a more complete map of the planet. Another game gets users to count impact craters to help scientists understand better the relative age of rocks on Mars’ surface.

Nasa hopes the mix of real data and fun will also inspire the planetary scientists of tomorrow. “We really need the next generation of explorers,” says Michelle Viotti, from the agency’s Jet Propulsion Laboratory, which oversees Mars missions. “And we’re also accomplishing something important for Nasa. There’s so much data coming back from Mars. Having a wider crowd look at the data, classify it and help understand its meaning is very important.” Software giant Microsoft has been a major contributor to the technology powering Be A Martian. The website was built on the Microsoft Windows Azure Platform, using the company’s Silverlight interface and its “Dallas” service to house all the information. “The beauty of this type of experience is that it not only teaches people about Mars and the work Nasa is doing there, but it also engages a large group of people to help solve real challenges that computers cannot solve by themselves,” said Marc Mercuri from Microsoft.


Most of Antarctica has about 2 1/2 miles of ice covering it, and that cold, white wasteland is what most people picture when they think of the South Pole. But a series of dry valleys in Antarctica, about 4,000 kilometers square, have no ice on them at all. The moisture is sucked from the dry valleys by a rain shadow effect — winds rushing over them at speeds up to 200/mph — leaving a bizarre and fascinating landscape, which looks more like Mars than the rest of our planet. Lacking the resources (or cojones) to go there myself, these photos are by scientists and researchers who’ve been there, and are included as part of galleries on the McMurdo Dry Valleys Management Area website. The Valleys have been carved out by glaciers that have retreated, exposing valley floors and walls that typically have a top layer of boulders, gravel and pebbles, which are weathered and wind-sorted. Lower layers are largely cemented together by ice. Unusual surface deposits include marine sediments, ash, and sand dunes.

Antarctic Research Helps Shed Light On Climate Change On Mars / Sep 01, 2008

Researchers examining images of gullies on the flanks of craters on Mars say they formed as recently as a few hundred thousand years ago and in sites once occupied by glaciers. The features are eerily reminiscent of gullies formed in Antarctica’s mars-like McMurdo Dry Valleys. The parallels between the Martian gullies and those in Antarctica’s McMurdo Dry Valleys were made using the latest high-resolution images and technology from satellites orbiting Mars to observe key details of their geological setting.

On Mars, the gullies appear to originate from cirque-like features high on pole-facing crater-interior walls, especially those within the Newton crater, 40 degrees south, examined for the study. In addition to the cirque-like features, the evidence cited for former glaciation includes bowl-shaped depressions fringed by lobate, viscous-flow deposits that extend well out onto the crater floor. “These bowl-shaped depressions reflect the former location of relatively pure glacier ice,” noted David R. Marchant, an Associate Professor of Earth Sciences at Boston University, and co-author of the study published in the August 25th issue of the Proceedings of the National Academy of Sciences with James W. Head of Brown University, lead author, and Mikhail A. Kreslavsky of the University of California, Santa Cruz.

As conditions on Mars shifted toward reduced snowfall at this site, clean ice on the crater wall sublimated, leaving a hole, whereas ice containing appreciable rock-fall debris out on the crater floor became covered with thin rubble, preventing complete volatile loss. But even as the last glaciers vanished, minor snow likely continued to fall. “This late-stage snow could accumulate in depressions on the crater wall and, in favorable microclimate settings, melt to produce the observed gullies and fans,” said Marchant. “The results”, he said, “are exciting because they establish a spatial link between recent gullies and accumulation of glacier ice, strengthening the case for surface melt water flow in the formation of gullies on Mars”.

Other candidate processes include dry debris flows and melting of shallow ground ice, but the sequence of events demonstrating recent snowfall in Newton Crater make surface melting of snow banks an appealing choice. In fact, both Marchant and Head have observed similar processes at work in the development of modern gullies within some of the coldest and driest regions of Antarctica. The authors conclude that changes in the rate and accumulation of snow in Newton Crater are likely related to changes in the inclination of Mars’ spin access, or obliquity.

At obliquities even greater than those postulated for glaciation of Newton Crater, the same authors and colleagues postulated even larger-scale mountain glaciation near the equator, on and extending out from the Tharsis volcanoes. The evidence suggests a link between obliquity, mid-latitude glaciation, and gully formation on Mars. Rather than being a dead planet, the new data are consistent with dynamic climate change on Mars, and with episodes of alpine glaciation and melt water formation in the recent past that rival modern alpine glaciation and gully formation in the coldest and driest mountains of Antarctica.


“Or, perhaps evolved technical intelligence has some deep tendency to be self-limiting, even self-exterminating. After Hiroshima, some suggested that any aliens bright enough to make colonizing space ships would be bright enough to make thermonuclear bombs, and would use them on each other sooner or later. Maybe extra-terrestrial intelligence always blows itself up.”

ET too bored by Earth transmissions to respond
by Tom Simonite  /  18 December 2007

Messages sent into space directed at extraterrestrials may have been too boring to earn a reply, say two astrophysicists trying to improve on their previous alien chat lines. Humans have so far sent four messages into space intended for alien listeners. But they have largely been made up of mathematically coded descriptions of some physics and chemistry, with some basic biology and descriptions of humans thrown in. Those topics will not prove gripping reading to other civilisations, says Canadian astrophysicist Yvan Dutil. If a civilisation is advanced enough to understand the message, they will already know most of its contents, he says: “After reading it, they will be none the wiser about us humans and our achievements. In some ways, we may have been wasting our telescope time.” In 1999 and 2003, Dutil and fellow researcher Stephane Dumas beamed messages in a language of their own design into space. Now, they are working to compose more interesting messages. “The question is, what is interesting to an extraterrestrial?” Dutil told New Scientist. “We think the answer is using some common ground to communicate things about humanity that will be new or different to them – like social features of our society.” Fortunately those subjects are already being described mathematically by economists, physicists and sociologists, he adds.

Vexing problems
One topic the two researchers are already composing messages about is the so-called ‘cake cutting problem’. “How do you share out resources is a classical problem for all civilisations,” he says. Democracy is also a potentially eye- or antenna- catching subject. “The maths shows that with more than two choices, there is no perfect electoral procedure,” says Dutil. He has started work on encoding this into a message in which “we can explain our methods and ask, ‘What do you use on your planet?'”

Social physics – the application of mathematical techniques to societies – also provides good material potentially interesting to the alien. “We know that every human social network behaves as a gas, what we don’t know is how universal that is beyond Earth.” Aliens may be asking themselves similar questions, he adds. Another fundamental challenge for very old civilisations is using resources sustainably to avoid dying out, says Dutil. “Any good examples out there could help a lot on Earth.”
Human nature Dumas has designed software that is like a word processor for composing messages in the pair’s symbolic language. There is also a separate automatic decoder, which should help avoid slip-ups like the missing factor of 10 in the duo’s 1999 message.

Douglas Vakoch, director of interstellar message composition at the search for extraterrestrial intelligence at the SETI Institute in Mountain View, California, US, agrees that we humans need to make our interstellar chat more compelling. “If we only communicate something the receiver already knows, it is not going to be very interesting.” Vakoch has recently been holding workshops at sociology and anthropology conferences to try and widen participation in messaging extraterrestrials beyond astrophysicists. “I think perhaps the most important question is: how do we represent what being a human is? And those disciplines can really help,” says Vakoch.

‘We’ll get back to you’
But Vakoch points out that email-like messages may not be the best approach. One alternative is to send software code for an avatar that could answer basic alien questions. That would get around the problem of the delays produced by large distances across space. “If someone replies to your message saying, ‘I don’t understand. Can you repeat that?’ it will take decades, centuries or millennia to know,” says Vakoch. “Another approach is to send a lot of stuff and hope there is enough redundancy for them to spot patterns,” he adds. “We could just send the encyclopaedia.” Dutil agrees other options are worth exploring, but points out that sometimes only a message will do. “It would make sense to have an ‘answer phone’ message ready in case we are contacted,” he explains, “just to say, ‘we’ll get back to you,’ while we figure out what to do.” Tell us who you think should be in charge of composing messages to ET in our blog.




Q. So how many star systems has I Love Lucy already reached?
A. I Love Lucy was popular in the fifties, so the earliest shows have travelled 40 light-years into space. There are about 100 stars within that distance, and if there are any inhabited planets encircling these nearby stellar sites, they might be watching Lucy and Desi if they’ve bothered to build a very large antenna capable of
working at the relatively low broadcast frequencies of television (about 100 MHz).


“We’ve already violated the prime directive by sending porn and rock music into space with the Voyager and Pioneer messages respectively. Should an advanced alien civilization find and decode the Pioneer golden record, their biggest worry would be to be sued by the RIAA for illegally downloading Johnny B. Goode.”





This message was sent from the Arecibo radio telescope in Puerto Rico to the M13 star cluster, 25,000 light years away (150,000 million million miles). Consisting of 1,679 binary digits, the bits can be arranged into a rectangle of 73 rows and 23 columns (two prime numbers) to reveal a message.

Encoded are: the numbers one through to 10; atomic numbers of key elements such as hydrogen, carbon and oxygen; a graphic of DNA, along with an estimate of its complexity; a graphic figure of a man and the human population of Earth; a graphic of our solar system; and a graphic of the Arecibo radio telescope. The signal took 169 seconds to send and was not repeated.


TOO NOISY—-we-mead-you-know-harm.html
“Alien” message tests human decoders
by Will Knight  /  08 January 2002

A message that will be broadcast into space later in 2002 has been released to scientists worldwide, to test that it can be decoded easily. The researchers who devised the message eventually hope to design a system that could automatically decode an alien reply. Unlike previous interstellar broadcasts, the new message is designed to withstand significant interference and interruption during transmission. “People have tried sending messages in the past, but have not accounted for noise,” says Yvan Dutil, who currently works for a Canadian telecommunications company, but developed the message as a private project with Stephane Dumas, who works at the Defence Research Establishment Atlantic in Canada.

If new message had been based on language, it would be impossible for an alien intelligence to decode it. So, instead, a two-dimensional image was converted into a binary string of ones and zeros. These can then easily be transmitted as a radio or laser signal. “Currently, most resources are focused on signal detection, and not
message composition or decoding,” says Brian McConnel, author of Beyond Contact: A Guide to SETI and Communicating with Alien Civilisations. “I think it is important to research the latter because the worst-case scenario would be positive confirmation of an ET signal that nobody can comprehend.”

Alien code
The image has not been revealed to those playing the role of alien decoders and about 10 per cent meaningless noise has been added to the data. Some parts have even been deleted. This degradation of the message is intended to simulate the interference that might be experienced during transmission to distant planets. Dutil says that the binary string is designed to provide clues that should make it decipherable even with such significant disruption. The sensitivity of interplanetary communications was demonstrated in 1999 when a previous message written by Dutil and Dumas was found to contain an error that could have seriously confused an alien recipient if it had not been corrected in the nick of time.

Automatic decoding
The pair have an even grander plan for the future – to develop a software system that can automatically decode alien messages, regardless of excess noise. A number of telescopes around the world are used to search for patterns in the radio waves that reach Earth. Dutil says that if a message were identified, it might be possible to decode it using an automated system based on well-developed techniques used in cryptanalysis, as well as principles of linguistic and statistical analysis. However, Douglas Vakoch, head of the Interstellar Message Group at the SETI (Search for Extraterrestrial Intelligence) Institute in California, says that deciphering a reply may prove very tricky. “Our biggest challenge will be to keep open to new types of messages that we had not previously considered,” he says. “That’s why the SETI Institute is sponsoring a series of workshops on interstellar message composition, aimed at identifying radically new ways of constructing messages.” The new message can be downloaded from the project homepage. Dutil and Dumas hope that it will be transmitted by laser as early as February 2002, by Celestis, a US company specialising in space projects.


The TAM was created by Russian teens in Moscow Center of Teen Activity and was transmitted at 18:00 UT on August 29, 2001 from the 70-m dish of Evpatoria Deep Space Center to the Sun-like star HD 197076 in the Dolphin Constellation. The total duration of the transmission was 2 hours 12 minutes. The message consists of three distinct parts:

1. Sounding Section — coherent signal with slow Doppler wavelength tuning to imitate the transmission from Sun’s center (10 min)
2. Analog Section — Theremin concert to Aliens (15 min)
3. Digital Section — Message: Logo of TAM, Greeting to Aliens both in Russian and English, Image Glossary (70 min).

The Coherent Sounding Signal was transmitted in order to help Aliens detect the message and to investigate some radio propagation effects in the interstellar medium. The Analog Information represents music, performed on the Theremin. This musical instrument produces quasi sinusoidal signal, which is easily detectable across interstellar distances. There were 7 musical compositions in the 1st Theremin Concert for Aliens:

1. Melody of Russian romance “Egress alone I to the ride”
2. Beethoven. Finale of the 9th Symphony.
3. Vivaldi. Seasons. March. Allegro.
4. Saen-Saens. Swan.
5. Rakhmaninov. Vokalise.
6. Gershwin. Summertime
7. Melody of Russian folk-song “Kalinka-Malinka”

The Concert program was composed by Russian teens. The Theremin performers were Lidia Kavina, Yana Aksenova and Anton Kerchenko from the Moscow Theremin Center. The Digital Information includes the Logo of TAM, Greetings from teens to Aliens, written both in Russian and English, and an Image Glossary. The total size of the digital information is 648,220 bits and was transmitted at a rate 100 bits per second. This section was composed by teens from different sites of Russia – Moscow. Kaluga, Zelenogorsk, Voronezh. The 28 images follow in the menu to the left.


Yvan Dutil
Yvan [dot] Dutil [at] sympatico [dot] ca

Stephane Dumas
stephane_dumas [at] sympatico [dot] ca

Alexander L. Zaitsev
alzaitsev [at] ms [dot] ire [dot] rssi [dot] ru




Who Speaks for Earth?
After decades of searching, scientists have found no trace of extraterrestrial intelligence. Now, some of them hope to make contact by broadcasting messages to the stars. Are we prepared for an answer?
by David Grinspoon  /  December 12, 2007

Alexander Zaitsev, Chief Scientist at the Russian Academy of Sciences’ Institute of Radio Engineering and Electronics, has access to one of the most powerful radio transmitters on Earth. Though he officially uses it to conduct the Institute’s planetary radar studies, Zaitsev is also trying to contact other civilizations in nearby star systems. He believes extraterrestrial intelligence exists, and that we as a species have a moral obligation to announce our presence to our sentient neighbors in the Milky Way–to let them know they are not alone. If everyone in the galaxy only listens, he reasons, the search for extraterrestrial intelligence (SETI) is doomed to failure. Zaitsev has already sent several powerful messages to nearby, sun-like stars–a practice called “Active SETI.” But some scientists feel that he’s not only acting out of turn, but also independently speaking for everyone on the entire planet. Moreover, they believe there are possible dangers we may unleash by announcing ourselves to the unknown darkness, and if anyone plans to transmit messages from Earth, they want the rest of the world to be involved. For years the debate over Active SETI versus passive “listening” has mostly been confined to SETI insiders. But late last year the controversy boiled over into public view after the journal Nature published an editorial scolding the SETI community for failing to conduct an open discussion on the remote, but real, risks of unregulated signals to the stars. And in September, two major figures resigned from an elite SETI study group in protest. All this despite the fact that SETI’s ongoing quest has so far been largely fruitless. For Active SETI’s critics, the potential for alerting dangerous or malevolent entities to our presence is enough to justify their concern.

“We’re talking about initiating communication with other civilizations, but we know nothing of their goals, capabilities, or intent,” reasons John Billingham, a senior scientist at the private SETI Institute in Mountain View, California. Billingham studied medicine at Oxford and headed NASA’s first extraterrestrial search effort in 1976. He believes we should apply the Hippocratic Oath’s primary tenet to our galactic behavior: “First, do no harm.” For years Billingham served as the chairman of the Permanent Study Group (PSG) of the SETI subcommittee of the International Academy of Astronautics, a widely accepted forum for devising international SETI agreements.
But despite his deep involvement with the group, Billingham resigned in September, feeling the PSG is unwisely refusing to take a stand urging broad, interdisciplinary consultation on Active SETI. “At the very least we ought to talk about it first, and not just SETI people. We have a responsibility to the future well-being and survival of

Billingham is not alone in his dissent. Michael Michaud, a former top diplomat within the US State Department and a specialist in technology policy, also resigned from the PSG in September. Though highly aware of the potential for misunderstanding or ridicule, Michaud feels too much is at stake for the public to remain uninvolved in the debate. “Active SETI is not science; it’s diplomacy. My personal goal is not to stop all transmissions, but to get the discussion out of a small group of elites.” Michaud is the original author of what became the “First SETI Protocol,” a list of actions to take in the event of a SETI success. In the late 1980s, several international organizations committed to its principles: First, notify the global SETI community and cooperate to verify the alien signal. Then, if the discovery is confirmed, announce it to the public. Finally, send no reply until the nations of the world have weighed in. A future “Second SETI Protocol” was meant to refine the policy for sending mes- sages from Earth, but the effort quickly became complicated. Everyone agreed that if a message were received, broad global dialogue concerning if and how to respond must take place before any reply could be sent. The rift arose over whether or not the Protocol should also address Active SETI transmissions made before any signal is detected.

At a meeting last year in Valencia, Spain, a divided PSG voted to change Michaud’s draft of the Second Protocol. They deleted language calling for “appropriate international consultations” before any deliberate transmissions from Earth, overriding the concerns of Billingham and Michaud and triggering Nature’s editorial. As Michaud describes it, “Last fall, this became an unbridgeable gap. They brought it to a vote but there was no consensus. Those with dissenting views were largely cut out of the discussion.” Michaud and Billingham feel that by not explicitly advocating a policy of international consultations, the SETI PSG is tacitly endorsing rogue broadcasters.

Seth Shostak, the current chair of the SETI PSG, maintains that Nature got it wrong, that in Valencia there was no organized effort to discourage open and transparent debate about the wisdom of sending signals. As the SETI Institute’s senior astronomer, Shostak has been involved in the science and policy of SETI for many years, and often seems to act as public spokesman for the Institute and for SETI in general. He says it’s inappropriate for the PSG to set global guidelines for Active SETI. “Who are we to tell the rest of the world how to behave? It would be totally unenforceable.”

Michaud and Billingham agree that the PSG can’t make policy for the whole world. But rather than sweep the question under the rug, they believe it is the responsibility of the SETI community to facilitate the wider conversation that must take place. “We feel strongly that the discussion must involve not just astronomers, but a broad spectrum of social scientists, historians, and diplomats,” explains Billingham. “This was simply about jurisdiction,” Shostak insists. The First Protocol, he says, is about self-policing; the Second isn’t. “If we found a signal, it would be a result of our own research. Therefore we felt it was responsible to have an agreed-upon policy about what to do next.” Shostak also worries that drafting guidelines for sending messages to aliens could generate bad press. SETI has always struggled for respectability. In the 1970s and 80s, NASA supported some listening programs, but government funding was cut off in 1993 amid congressional ridicule. Thanks to private funding, SETI has rebounded since then, but is still vulnerable to association with tabloids and talk radio guests claiming personal contact with aliens. Publicizing the real debate over rules of conduct for talking to extraterrestrials, Shostak reasons, wouldn’t do much to help counter this vision.

Long before he was an eager practitioner of Active SETI, Alexander Zaitsev was already a respected astronomer investigating planets using huge blasts of radar energy from the 70-meter radio telescope at the Evpatoria Deep Space Center in Crimea, Ukraine. Planetary radar studies rely on powerful, focused beams to “illuminate” distant objects, though much of this energy misses its target. The beams would be fleeting if seen from other stars that, by chance, lay along their path. But aimed and modulated to contain pictures, sounds, and other multimedia, they very easily become calling cards from Earth. On balance, it’s relatively simple to send signals, so why have we just been listening?

SETI doctrine states that anyone we hear from will almost certainly be much more advanced than we are. Simply put, our capabilities are so rudimentary that any chance of detecting an alien transmission would require that it be broadcast powerfully and continually on millennial timescales. We can’t predict much about alien civilizations, but we can use statistical mathematics to derive simple, robust relationships between the number of putative civilizations, their average longevity, and their population density in the galaxy. The chance of getting a signal from another baby race like ours is infinitesimally small. As Shostak says, “We’ve had radio for 100 years. They’ve had it for at least 1,000 years. Let them do the heavy lifting.”

This is one reason why most SETI pioneers advocated a “first, just listen” approach. But there is another: What if there is something dangerous out there that could be alerted by our broadcasts? This ground has been explored in numerous scientific papers and, of course, in countless works of science fiction. Few people alive today embody the convergence of hard science and fictional speculation better than David Brin, an author of both peer-reviewed astronomy papers and award-winning science fiction novels. In an influential 1983 paper titled “The Great Silence,” Brin provided a kind of taxonomy of explanations for the lack of an obvious alien presence. In addition to the usual answers positing that humanity is alone, or so dull that aliens have no interest in us, Brin included a more disturbing possibility: Nobody is on the air because something seeks and destroys everyone who broadcasts. Like Billingham and Michaud, he feels the PSG is dominated by a small number of people who don’t want to acknowledge Active SETI’s potential dangers.

Even if something menacing and terrible lurks out there among the stars, Zaitsev and others argue that regulating our transmissions could be pointless because, technically, we’ve already blown our cover. A sphere of omnidirectional broadband signals has been spreading out from Earth at the speed of light since the advent of
radio over a century ago. So isn’t it too late? That depends on the sensitivity of alien radio detectors, if they exist at all. Our television signals are diffuse and not targeted at any star system. It would take a truly huge antenna–larger than anything we’ve built or plan to build–to notice them.

Alien telescopes could perhaps detect Earth’s strange oxygen atmosphere, created by life, and a rising CO2 level, suggesting a young industrial civilization. But what would draw their attention to our solar system among the multitudes? Deliberate blasts of narrow-band radiation aimed at nearby stars would–for a certain kind of
watcher–cause our planet to suddenly light up, creating an obvious beacon announcing for better or worse, “Here we are!”

In fact, we have already sent some targeted radio messages. Even now they are racing toward their selected destinations, and they are unstoppable. Frank Drake sent the first Active SETI broadcast from the large radio telescope in Arecibo, Puerto Rico, in November 1974. In its narrow path, the Arecibo message was the most powerful signal ever sent from Earth. But it was aimed at M13, a globular star cluster about 25,000 light years away. At the earliest, we could expect a reply in 50,000 years.

More recently, Zaitsev and his colleagues sent a series of messages from their dish at Evpatoria. In 1999 and 2003 they sent “Cosmic Call” I and II, transmissions containing pictograms meant to communicate our understanding of the universe and life on Earth. In 2001, Zaitsev and a group of Russian teenagers created the “Teen-Age Message to the Stars,” which was broadcast in August and September of that year in the direction of six stars between 45 and 70 light years from Earth. The Teen-Age Message notably included greetings in Russian and English, and a 15-minute Theremin symphony for aliens. Unlike Drake’s Arecibo message, Zaitsev’s messages target nearby stars. So if anyone wishes to reply, we may receive it in the next century or two.

Along with the famous plaques attached to Pioneer 10 and 11 and the two phonograph records carried by Voyager 1 and 2–four spacecraft that will soon leave our Solar System–these messages are mostly symbolic efforts unlikely to betray our presence to the denizens of planets orbiting other stars. Our civilization is still hidden from all but those ardently searching for our kind, or those so far beyond our level of sophistication that we couldn’t hide from them if we wanted to. To date, all our “messages to aliens” are really more successful as communications to Earth, mirrors reflecting our dreams of reaching far beyond our terrestrial nursery.

For now, the dissenters have given up on the SETI PSG, but there’s still hope for a solution to the standoff. At the PSG’s 2007 meeting held in Hyderabad, India this September, the group implicitly accepted the reality of Active SETI risks by adopting a standard called the “San Marino Scale,” a formula for assessing the risk of a given
broadcast program. Michaud admits that the scale “is a useful starting point for discussion.”

When pressed, everyone involved in the recent controversy agrees that harmful contact scenarios cannot be completely ruled out. Active SETI critics like Billingham, Michaud, and Brin don’t support a blanket ban on transmissions, and even Zaitsev accepts that open and multinational discussion is needed before anyone pursues transmission programs more ambitious and powerful than his own. The major disagreement is actually over how soon we can expect powerful transmission tools to become widely available to those who would signal at whim.

At present, the radio astronomy facilities potentially capable of producing a major Active SETI broadcast are all controlled by national governments, or at least large organizations responsible to boards and donors and sensitive to public opinion. However, seemingly inevitable trends are placing increasingly powerful technologies in the hands of small groups or eager individuals with their own agendas and no oversight. Today, on the entire planet, there are only a few mavericks like Zaitsev who are able and willing to unilaterally represent humanity and effectively reveal our presence. In the future, there could be one in every neighborhood.

So far SETI has turned up no evidence of other intelligent creatures out there seeking conversation. All we know for certain is that our galaxy is not full of civilizations occupying nearly every sun-like star and sending strong radio signals directly to Earth. In the absence of data, the questions of extraterrestrial intelligence, morality, and behavior are more philosophy than science. But even if no one else is out there and we are ultimately alone, the idea of communicating with truly alien cultures forces us to consider ourselves from an entirely new, and perhaps timely, perspective. Even if we never make contact, any attempt to act and speak as one planet is not a misguided endeavor: Our impulsive industrial transformation of our home planet is starting to catch up to us, and the nations of the world are struggling with existential threats like anthropogenic climate change and weapons of mass destruction. Whether or not we develop a mechanism for anticipating, discussing, and acting on long-term planetary dangers such as these before they become catastrophes remains to be seen. But the unified global outlook required to face them would certainly be a welcome development.




We’ve been trying to make contact with aliens for years. Now the day is fast approaching when we might finally succeed. But will our extraterrestrial friends come in peace? Or will they want to eat us? An astronomer explores the perils of a close encounter.
Meet the neighbours: Is the search for aliens such a good idea?
by David Whitehouse  /  25 June 2007

We are making dangerous discoveries in space. In April, astronomers found, on our cosmic doorstep, a planet dubbed Gliese 581c. Nestling close to a dim red star, it’s a rocky world only a little larger than Earth. Like Earth, it could support liquid water. And to scientists, liquid water means the possibility of life. Gliese 581c must be an ancient world, for it circles a star that is far older than our Sun. The question is, has any advanced life evolved on that planet, or on the many other places that must be suitable sites, not so very far away?

Recently, British astronomers told the government that we might find life in space. It is only a matter of time, this year perhaps, before astronomers detect a planet even more similar in size and mass to our Earth, circling another star. And when we find that planet, we may discover a lot more than new oceans and land masses. Astronomers have been actively looking for intelligent life in space since 1960, when Frank Drake started Project Ozma, using a radio telescope to listen for signals from two nearby sun-like stars – Drake knew that radio waves travel more easily through the cosmos than light waves. He didn’t hear anything back. Since then, our searches have become more thorough thanks to larger radio telescopes and more sophisticated computers that look for fainter signals. But we still have no signal from ET. Should we want to?

This is not just a matter for astronomical research involving distant worlds and academic questions. Could it be that, from across the gulf of space, as HG Wells put it, there may emerge an alien threat? That only happens in lurid science fiction films, doesn’t it? Well, the threat is real enough to worry many scientists, who make a simple but increasingly urgent point: if we don’t know what’s out there, why on Earth are we deliberately beaming messages into space, to try and contact these civilisations about whom we know precisely nothing?

The searchers are undeterred. They argue that because of the vastness of space – even if there are 10,000 transmitting societies nestled in the stellar arms of the Milky Way – we might have to search millions of star systems to find just one. But rather than just listening, some want to announce our presence to the cosmos. In 1974, the then newly resurfaced Arecibo radio telescope in Puerto Rico (made famous in the James Bond film Goldeneye) reversed its usual role of just listening, and transmitted a series of radio pulses towards the M13 star cluster. It sent 1679 pulses in all, which, when arranged in binary form into 23 columns and 73 rows, would form a message from humanity. It was seen as a symbolic gesture, showing those on Earth that we had the technology to send a signal across our galaxy and – if we were on the other side of the relationship – to receive a signal as well. But some scientists objected. Sir Martin Ryle, the Astronomer Royal at the time, warned that ” any creatures out there [might be] malevolent or hungry”.

Now, after a long period when there were no deliberate transmissions into space, a new round is about to take place and more are planned. A team led by the astronomer Alexander Zaitsev has already beamed forth a series of interstellar messages, including pictorial and musical transmissions, from the Evpatoria radio telescope in the Ukraine. Another group in Brazil, the Grupo Independente de Radio Astronomos in Rio de Janeiro, claims to have transmitted as well. Half a dozen commercial companies have also sprung up, among them Cosmic Connexion, a firm based near Cape Canaveral in Florida. The Cosmic Connexion website invites you to e-mail your messages to them and they will then beam them, free, into space and “introduce you to extraterrestrials”. At the moment, though, this is a low-power initiative whose signals won’t get far. Other companies offering the same service for a fee are soon to come online.

Many scientists, frightened by the danger that might lurk out there, have argued against our actively seeking contact with extraterrestrials. Jared Diamond, professor of evolutionary biology and Pulitzer Prize winner, says: ” Those astronomers now preparing again to beam radio signals out to hoped-for extraterrestrials are naive, even dangerous.” The fact is, and this should have been obvious to all, that we do not know what any extraterrestrials might be like – and hoping that they might be friendly, evolved enough to be wise and beyond violence, is an assumption upon which we could be betting our entire existence. When I was a young scientist 20 years ago at Jodrell Bank, the observatory in Cheshire, I asked Sir Bernard Lovell, founder of Jodrell Bank and pioneering radio astronomer, about it. He had thought about it often, he said, and replied: “It’s an assumption that they will be friendly – a dangerous assumption.”

And Lovell’s opinion is still echoed today by the leading scientists in the field. Physicist Freeman Dyson, of the Institute for Advanced Study in Princeton, has been for decades one of the deepest thinkers on such issues. He insists that we should not assume anything about aliens. “It is unscientific to impute to remote intelligences wisdom and serenity, just as it is to impute to them irrational and murderous impulses,” he says. ” We must be prepared for either possibility.” The Nobel Prize-winning American biologist George Wald takes the same view: he could think of no nightmare so terrifying as establishing communication with a superior technology in outer space. The late Carl Sagan, the American astronomer who died a decade ago, also worried about so-called “First Contact”. He recommended that we, the newest
children in a strange and uncertain cosmos, should listen quietly for a long time, patiently learning about the universe and comparing notes. He said there is no chance that two galactic civilisations will interact at the same level. In any confrontation, one will always dominate the other.

The Australian astronomer Ronald Bracewell, now of Stanford University, warns that other species would place an emphasis on cunning and weaponry, as we do, and that an alien ship dispatched our way is likely to be armed. Indeed, evolution on earth is, as they say, red in tooth and claw. And it’s likely that any creature we contact will also have had to claw its way up its own evolutionary ladder and may possibly be every bit as nasty as we are – or worse. Imagine an extremely adaptable, extremely aggressive super-predator with superior technology.

So should we stay quiet and ban these transmissions into space? When, as a newly minted young scientist, I was discussing this issue with the (late) influential astronomer Zdenek Kopal, he grabbed me by the arm and said in a tone of seriousness: “Should we ever hear the space-phone ringing, for God’s sake let us not answer. We must avoid attracting attention to ourselves.” Others have put it more graphically, saying that the civilisation that blurts out its existence might be like some early hominid descending from the trees and calling “here kitty” to a sabre-toothed tiger.

But not all scientists are worried. Frank Drake, who devised Project Ozma and who was also behind the Arecibo transmission says, “As I thought in 1974, the objections to sending interstellar messages were naive and carried no weight. The argument then, as now, is that humanity has been, and is making, its presence known through our TV and radio and military radars which, in many cases, release most of their radiated power into interstellar space.”

Radio waves from Earth, from TV and radio broadcasts and from powerful intercontinental military radars are leaking out into space. Some believe they could be detected, but should we go beyond this and actively announce our presence to the cosmos? Drake points out that our present terrestrial radio telescopes, if placed on nearby worlds, would be unable to detect these transmissions at distances beyond a few light years. However, aliens would be more advanced, he says, and it is quite within the abilities of current terrestrial technology to build telescopes, using the array approach, which could detect these transmissions from great distances in the galaxy. “The point here is that Earth has made its presence known by sending a multitude of signals. It is too late – we have made ourselves visible,” he adds.

But scientist and science-fiction author David Brin thinks those in charge of drafting policy about transmissions from Earth – ostensibly a body called the International Astronomical Union, which would make recommendations to the United Nations – are being complacent, if not irresponsible. Whatever has happened in the past, he doesn’t want any new deliberate transmissions adding to the risk. “In a fait accompli of staggering potential consequence,” he says, “we will soon see a dramatic change of state. One in which Earth civilisation may suddenly become many orders of magnitude brighter across the Milky Way – without any of our vaunted deliberative processes having ever been called into play.”

Michael Michaud, a former US diplomat and chairman of the Transmissions from Earth Working Group – a subdivision of the International Astronomical Union’s Search for Extraterrestrial Intelligence Study Group established in 2001 – is on the verge of resigning in frustration at the lack of discussion about the problem. He believes it is being confined to a narrow group of scientists who share the same limited astronomical viewpoints and he wants the study group widened beyond its current remit to include planetary scientists, philosophers, historians and so on. He sees it as a problem that affects all of humanity – and one that should be debated as such.

But despite these concerns, for the moment, the plans for deliberate transmissions from Earth go ahead and there is nothing anyone can do to stop them – or even demand a discussion beforehand. One thing is clear from our searches for ET – there is nobody transmitting strong interstellar beacons in our local vicinity. If “they” are out there, they are keeping quiet, prompting the question that they might know something we don’t.

Perhaps the aliens already know about us and are on their way. Or perhaps not. Intelligences – possibly vast, cool and unsympathetic – could be sweeping their skies looking for us. At the moment when they point their instruments in the direction of our sun – a commonplace yellow-dwarf star – they may well find nothing unusual, if no one’s sending messages in the other direction. Should we keep it that way?


Is Active SETI imperiling humanity?

Michael Michaud, a member of the SETI Permanent Study Group, has come out warning that Active SETI may be putting humanity in serious jeopardy. “Let’s be clear about this,” writes Michaud, “Active SETI is not scientific research. It is a deliberate attempt to provoke a response by an alien civilization whose capabilities, intentions, and distance are not known to us. That makes it a policy issue.” Proponents of Active SETI advocate that humanity deliberately transmit messages to outer space in hopes that an ETI will intercept them and learn of our existence. These signals would be different than regular radio transmissions in that they would be stronger, more focused, and contain actual messages for potential listeners. To bolster his case, Michaud lists an impressive retinue of scientists who agree with him, including sociobiologist Jared Diamond, Nobel Prize-winning biologist George Wald, and astronomers Robert Jastrow and Zdenek Kopal. Even lesser-known scientists have entered into the fray:

Biologist Michael Archer said that any creature we contact will also have had to claw its way up the evolutionary ladder and will be every bit as nasty as we are. It will likely be an extremely adaptable, extremely aggressive super-predator. Physicist George Baldwin predicted that any effort to communicate with extraterrestrials is fraught with grave danger, as they will show innate contempt for human beings. Robert Rood warned that the civilization that blurts out its existence on interstellar beacons at the first opportunity might be like some early hominid descending from the trees and calling “here kitty” to a saber-toothed tiger.

Michaud even brings physicist Freeman Dyson into the discussion–a man who has thought and written extensively on this subject. “Our business as scientists is to search the universe and find out what is there. What is there may conform to our moral sense or it may not,” writes Dyson, “It is just as unscientific to impute to remote intelligences wisdom and serenity as it is to impute to them irrational and murderous impulses. We must be prepared for either possibility and conduct our searches accordingly.”

Dyson posed two alternatives: Intelligence may be a benign influence creating isolated groups of philosopher-kings far apart in the heavens, sharing at leisure their accumulated wisdom. Or intelligence may be a cancer of purposeless technological exploitation sweeping across the galaxy. Michaud’s recommendations re: Active SETI? Do not transmit a signal more powerful than the Earth’s radio leakage (including radars) without international consultation. And by international consultation, Michaud means the UN. He’s obviously pretty serious. So, is Michaud right? Yes and no.

Yes, in that we could alert some kind of entity to our existence (like a dormant berserker probe). And yes, in that extraterrestrial agents (sentient or semi-sentient) may be quite malign or hold radically different moral values to our own. No, in that it’s highly, highly unlikely that bad guy ETIs are waiting in their spaceships for signs of less-advanced life so that they can scoot over and subjugate them. I consider this scenario to be rather outlandish–one that fails to take into account the likely existential changes that advanced ETIs will undergo as they evolve into postbiological civs.

Also, these fears fail to take into account the Fermi Paradox. It’s more likely that nobody’s out there listening. And even if there is, if evil ETIs wanted to overtake the Galaxy they could have easily done that by now. And as the Von Neumann/berserker probe scenario shows, the Galaxy could have been colonized (or sterilized) thousands, if not millions, of times over by now also. Yet clearly this hasn’t happened, which is an interesting data point that would seem to argue against the idea of imperialistic entities residing in the Galaxy. Consequently, I think Michael Michaud’s fears are quite exaggerated. Active SETI is likely as useless an endeavor as it is harmless.





“The eighteenth chapter is called the Ozma Problem, and poses a problem that Gardner claims would arise if Earth should ever enter into communication with life on another planet through Project Ozma. This is the problem of how to communicate the meaning of left and right, where the two communicants are conditionally not allowed to view any one object in common. The problem was first implied in Immanuel Kant’s discussion of left and right, and William James mentioned it in his chapter on ‘The Perception of Space’, Principles of Psychology, 1890. It is also mentioned by Charles Howard Hinton. The solution to the Ozma Problem is solved by the experiment conducted by Chien-Shiung Wu involving the beta decay of cobalt-60. This experiment was the first to disprove the conservation of parity. However, Martin Gardner adds in the last chapter of his book that the Ozma Problem is only solved within our galaxy: due to the nature of antimatter an antigalaxy would get the opposite result from the experiment conducted by Chien-Shiung Wu.”

To Keep on Looking : As we explore Mars, it forces us to imagine otherworldly evolution, challenging our definition of life and our sense of place in the solar system.
by Don Hoyt Gorman / April 26, 2007

Before NASA’s Mars Global Surveyor stopped calling home in November, the satellite, which had been orbiting our neighbor planet since 1997 and was the source of the Google Mars data, captured a compelling image. Relayed back to Malin Space Science Systems in San Diego, CA, was a photograph of what looked like a newly formed streambed that flowed down a gully into the base of a crater. Researchers were stunned because the exact location had been photographed five years prior by Surveyor and had revealed no such feature. The image itself is remarkable: It shows the flow–which appears lighter against the darker, older terrain around it–emerging from the Martian surface several hundred meters up a steep incline along the inside edge of a crater. It traces a course downhill until reaching the nearly flat bottom, where it spreads out like the fingers of the Mississippi Delta.

Mike Malin, the chief investigator and president of Malin Space Systems that built and operated Surveyor’s Mars Observer Camera, authored a paper in Science hypothesizing that what Surveyor had captured was in fact evidence of a brief, explosive flow of liquid water. It could only have been brief, because while the surface of Mars is around -63°C, the atmospheric pressure is so low that water boils even at that temperature. Malin suggested that water forcibly erupted onto the surface and raced down the slope before evaporating and leaving only the visible etching of shifted dust and rock.

It is a suggestion of water that leads to the suggestion of life. But the question is raised: Do we know what we’re looking for? In January we heard a hypothesis that gave us a new reason to look up in anticipation: Scientists at the American Astronomical Society meeting suggested that the Viking Landers of 1976 may have overlooked a form of microbial life that could, perhaps, exist on Mars. When the Viking missions were conceived, we had yet to find and identify here on our own planet forms of life that exist in almost unimaginably harsh environments: extreme cold, extreme pressure, extreme heat, extreme acidity. Conditions that approach the sort found on Mars have been colonized here on Earth by these extremophiles. Dirk Schulze-Makuch of Washington State University and Joop Houtkooper of Justus-Liebig University of Giessen in Germany looked back at the Viking missions and pointed out that the landers’ experiments (designed to find H2O-based life forms) would have failed to find signs of life that evolved the ability to use a water/hydrogen peroxide (H2O2) mixture–which could be well suited to Mars’s harsh climate. Extremophiles on Earth have adapted to use hydrogen peroxide — one organism, Acetobacter peroxidans, for instance, uses it as part of its metabolism. Schulze-Makuch and Houtkooper argued that if H2O2 biochemistry evolved on Mars, the Viking landers wouldn’t have detected it–in fact, the Viking experiments would have destroyed H2O2 biochemistry in whatever sample they collected. Which means, of course, that we now need to go back and look again, this time with a better appreciation for the ingenuity of life. Shortly after Schulze-Makuch and Houtkooper’s presentation, investigators at NASA’s Mars Phoenix mission (due to launch this August) started looking into whether its existing experiments could also be used to search for hydrogen-peroxide-based life. In April the National Academies’ “Weird Life” group is expected to present their “Astrobiology Strategy for the Exploration of Mars” paper, bringing together everything that has so far been learned about potential Martian astrobiology and presenting a plan for the search for life on Mars. The Mars Science Laboratory mission, which is scheduled to deliver the next-generation rover to Mars in late 2010, will carry with it a suite of tools and experimental capabilities that will drag Mars further still into the limelight of human understanding. Within a decade NASA is planning the Astrobiology Field Laboratory, a full-scale lander program whose only mission will be to uncover whatever traces of life Mars may harbor.

Of course, amidst all of these leading pictures and suggestive notions, there is the very real possibility that Mars is dead, and always has been. But as an exploratory species, we humans are also resolutely optimistic; we’ve spent billions of dollars and rubles and euros getting to Mars and exciting ourselves with the possibility of what may be waiting for us there. There is hope in these missions. It suggests that our drive to seek out new life runs hand in hand with a desire to find the familiar with the exotic…or, at the very least, find a colony of acidic bacteria.

Mars is no longer the ominous Red Planet of crisscrossed canals, and yet the more we know about it, the more we seem to want to find those canals there after all. As the explorations of our robotic and remote vehicles bring Mars closer to us, and as revelations continue to emerge about its atmosphere, its surface, its craters and ice cap, the planet continues to work its way into the big picture of human experience. It is becoming a more real and more exciting and more accessible place, not least as a physical and theoretical environment against which we can postulate some of our most novel scientific theories.

When we think of evolution, for instance, we think about single-celled organisms evolving to complex organisms, to fish, to amphibians, to birds or early primates, to hominids, to humans. We think of the Triassic to the Jurassic to the Cretaceous. We think of plate tectonics and old-growth forests. We don’t think of Mars. Mars isn’t
part of our rather Earthcentric worldview of evolution. Not yet.

Incorporating Martian evolution–or that of any other world, for that matter–into our understanding of life is one of the most profound paradigm shifts we are likely to experience in the biological sciences. It would put our own impressive and diverse natural history on a parallel existence with another entire category of life. And it
would bring with it an unending series of new questions and new scientific endeavor. That we will have to continue to redefine what constitutes life in order to conceive ways to find it is one of the greatest challenges that Mars and the rest of the universe have presented us.


Kenneth Nealson
email: knealson [at] wrigley [dot] usc [dot] edu

Douglas Capone
email: capone [at] wrigley [dot] usc [dot] edu


“Contact” Film Review
by Larry Klaes

The 1936 Berlin Olympics Broadcasts

“Another good move was the sending back of the television broadcast of the 1936 Summer Olympic Games in Berlin, Germany. Nazi leader Adolph Hitler (1889-1945) as one of our first representatives into the Milky Way galaxy? Unthinkable but true. I only wish I had not known this scene was coming (due to the novel) to feel the full impact of surprise that many theater audience members expressed when they and the film characters realized that the initially fuzzy black shape was a swastika grasped in an eagle’s talons.

I believe Sagan used this fact to make aware to those who produce and transmit our television and radio entertainment that their audience is possibly far wider and larger than they can imagine, thanks to the microwave leakage displayed at the very beginning of Contact. Perhaps a few of them (besides PBS) will try to show the Universe at large that not everything about the human race is relentless advertising, lame sitcoms, and cheesy movies of the week — but neither am I going to hold my breath waiting for that day to come from the mainstream media. Money is a far greater concern to most of them than impressing our galactic neighbors (or humanity) with the good traits we do possess.

Of course we can take some comfort from the knowledge that any ETI encountering our technological leakage will not completely understand what they have picked up from distant Earth. There is conjecture that the reason we have not heard from anyone out there yet is that they already know of the human race through our radio and television leakage and want nothing to do with us because of what it contains.

Perhaps, however, we are being too rough on our young selves. SETI scientists would be thrilled to detect an alien civilization by their own leakage and would not be too concerned, at least in the beginning, if that leakage contained either noble qualities or cultural dreck. Of course, who is to decide what is treasure and what is garbage when it comes to another society? Any good anthropologist knows that the trash created by a community tells you far more truth about themselves than any carefully written records or monuments. (11)”



Try plotting values in a three dimensional coordinate system.

A pattern begins to emerge.

Throw a gray scale on it; standard interpolation.

Rotate 90 degrees counterclock wise.

Willie enters commands.  All are mesmerized by the shadows taking form on the screen.

It has to be an image.  Stack it up, string-breaks every 60th character.

On the screen a distinct black and white moving image forms; grays define it even further.  The group is transfixed.  Kitz whispers to an aide who makes a call in
a hand radio.

Um… I’ve got an auxiliary sideband channel here.  I think it’s audio.

An otherworldly RUMBLING GLISSANDO of sounds joins the image, sliding up and down the spectrum… and then the faint SWELLING MUSIC is heard.  Ellie reaches over Willie and type more commands.  The picture rotates, rectifies, focuses —

What in the hell…?

It’s a hoax.  I knew it!

Um, excuse me, but would someone mind telling me what the hell is going on?

Other reactions range from astonishment to nervous laughter.  Ellie and Peter stare in utter amazement.

A grainy black and white image of a massive reviewing stand adorned with an immense Art Deco eagle. Clutched in the eagle’s concrete talons is a swastika. Adolph Hitler salutes a rhythmically chanting crowd. The deep baritone voice of an ANNOUNCER, scratchy but unmistakably GERMAN, BOOMS through the room.  The dark absurdity of the moment plays over Ellie’s face; helpless:

Anybody know German?

Kent tilts his head, closes his eyes.

The Fuhrer… welcomes the world to the German Fatherland… for the opening of the 1936 Olympic Games.

Hitler’s face fills the screen.  The crowd roars its approval.



in Berlin.  Police with hoses try to keep a mob of skinheads under control.

(in German) … the signal from the American observatory depicting Adolph Hitler has brought about chaos in the streets of Berlin, where hundreds of neo-Nazis gathered to swear eternal fealty…

Slowly WIDEN to reveal a monitor wall.

A kaleidoscopic display of global news coverage of the event.  Demonstrations in a dozen cities, commentary from pundits, Aryan leaders and Auschwitz survivors.  A single figure sits before the monitors, taking in the cacophony.

Forty million people die defeating that sonofabitch and he becomes our first ambassador to another civilization?  It makes me sick.

With all due respect, the Hitler broadcast from the ’36 Olympics was the first television transmission of any power that went into space. That they recorded it and sent it back is simply a way of saying ‘Hello, we heard you –‘

“Carbon-based bipeds appear to walk using two limbs while balancing precariously in a semi-upright posture but may be evolving rudimentary transportation systems based on the wheel.”

As preparations near completion for the return of the Olympics Games to their ancestral home in Athens, the time is ripe to revisit whether the Olympics has been our diplomatic calling card in other places beyond the home planet. As the world prepares for the 2004 Olympics in Athens, one can ask the question: Are we on Earth the only ones who will watch the games?

Recall that a key story point in the Carl Sagan novel, “Contact”, relies on the unique premise that we are not the only onlookers. Sagan’s scenario depends on the 1936 Olympic Games in Berlin as symbolically transmitting our existence beyond the solar system. Earth inhabitants showed their interest in contests for national pride and
athletic skills to a listening audience on the nearby star Vega. In the novel and screenplay based on the book, our own message in a bottle then boomerangs back to us, as a greeting from another world that they have heard us.

The plot device that the Earth leaks intelligent signals has appeared in many science fiction stories of first contact. Broadcasting early radio shows or even reruns of “I Love Lucy” to another culture on the home world, much less another planet, has long been a source of potential bemusement. How would such a randomly selected reflection of our culture be interpreted?

Perhaps Sagan chose to single out first transmission as the 1936 Berlin Games because the content is so antithetical to what we might have hoped for. Or in an ideal case, a warlike contest of brawn and nationalism seems less than what one might have planned as a friendly greeting. What as a species could show us as less prepared for greeting another civilization than the way we greet each other? After all the ’36 Games advertised the politics of a nationalistic Germany, on the precipice of the bloodiest war in human history, when virtually no part of our globe could remain untouched by battle and conflict. Even the notion of competitive games or a contest to rank national and individual power, while oftentimes used historically to trigger truces or peace talks, also represents a metaphor for unabashed cultural
ambitions and seemingly arbitrary or artificial borders that simply disappear when viewed from space.

In that context, what maturity can humans portray to species even more unlike ourselves, not just athletically but intellectually, culturally or morally? As David Grinspoon noted on this dilemma in his book, “Lonely Planets: The Natural Philosophy of Alien Life”, an advanced civilization observing happenings on Earth might easily reply to our first signal: “Humans of the planet Earth, you want to encounter other beings? First you have to learn to live with your different people?” Was this challenge encapsulated by the 1936 Berlin Olympics?

From his years in designing SETI strategies, University of Washington Professor, Woody Sullivan thinks what Hollywood did with Carl Sagan’s book, “Contact”, particularly the first half, is about as close as a popular film can get to what it’s like to do real SETI research. Much of the opening sequence owes a debt to Sullivan, since he spearheaded the scientific understanding that the Earth is leaking electromagnetic signals all the time, mainly from TV and some military radars. Twenty-five years ago, “most SETI was set up mainly to look at beacons from another civilization. But we don’t have a devoted beacon broadcasting from Earth even. A priori, we don’t know that a civilization would set up a beacon. But we Earthlings are leaking all the time, just from our daily activities.”

Just as the film, “Contact”, begins, the viewer is taken on a voyage, as if riding such a signal from the depths of the universe until it zooms back towards Earth. Before Sullivan’s work, previous SETI strategists more often thought of broadcast sources from another civilization as likely to be directed beacons, or singularly devoted
transmitters. Instead Sullivan supposed a viewpoint about the more constant background noise, one that unavoidably might date back to the film’s key plot-point when the advanced civilization finds the first terrestrial TV broadcast–the carrier signal when Adolf Hitler hauntingly introduced the 1936 Olympic Games in Berlin. “These are not great examples of our civilization,” said Sullivan.

“I call this eavesdropping,” continues Sullivan. “Sometimes when you eavesdrop, you get a better idea of what is really going on, say at a party. So when another civilization is eavesdropping on us, they may actually get a better idea about what is going on with Earth. There is more to Earth, as a planet, than what we could send on the gold record that travelled on the Voyager spacecraft. We, as a planet, are not just about listening to Chuck Berry.”

It is, according to Sullivan, easy to miss whether TV coverage of the Olympics can serve as an effective SETI message. Particularly when the picture itself, the moving color image, is the least of what an advanced civilization might want to watch, the physics of TV is more important than the actual content carried. Sullivan notes “the input is not actual TV programs in the broadcast signal. But I was talking first about the video carrier, which is a single frequency carrier. Your TV locks onto it. You can’t get the whole program information. From another planet, you could get alot or dozens of those carriers, about a rotating planet with doppler shifts. That communicates alot of information to a receiver.”

Whether the 1936 or 2004 Olympics represents a global signal that we leak apparently has less to do with the event itself and more to do with the electromagnetic spectrum. Sullivan considers “what signals we Earthlings are optimally leaking to our neighbors…should be broadly spread, strong, and possibly discernable as an intelligent signal… So for a good signal for reception, you want to balance a trade-off between both powerful and broad-area beaming.”

Sitting down to watch the Olympics from 10 to 100 light-years away may not reveal much of interest about a race of carbon-based bipeds. We will leak the 2004 Games to travel into deep space, just like we did with the 1936 Games. Most of what qualifies as signals of sufficient persistence and strength have a small probability of reaching just the right antenna. But chances are better that another civilization will not be caught watching our TV. Sullivan concludes TV is only one way we declare ourselves outside our solar system: “Military radar, called the Ballistic Military Early Warning System or BMEWS, is a very powerful broadcast, but carries no real information. There are a couple other strong radars on the planet. The strongest radar is Arecibo, but it covers a very tiny bit of sky. The odds that you were in that patch, or broadcast path, is unlikely.”

Whatever the source of our leaked signals, there is a timeliness to considering how we decorate our own local solar neighborhood. As the SETI Institute’s Jill Tarter, often cited as the inspiration for the lead scientist in the movie “Contact” describes: “When you realize that you live in the first generation of humans with access to a
technology that might answer the age-old question, ‘Are we alone?’ all other scientific questions fade in importance.”


THE LISTENERS, by James Gunn

“Here the aliens contact Earth to give us all their history and knowledge in order to preserve as much of themselves as they can before their star Capella expands into a red giant and renders them extinct. These ETI do not intend to conquer the human race. They do not possess starships with warp drives or subspace radios. The transmissions between Capella and Earth move at the speed of light and no faster (a message from Capella takes 45 years to reach us [at 186,000 miles per second, or 300,000 kilometers per second]). The story therefore stretches over hundreds of years, as a real two-way communication between distant star systems would take.

If an ETI were transmitting to Earth in a deliberate and non-hostile attempt to communicate, the message contents would most likely be about their culture and what they know of the Cosmos. Preserving themselves by sending this information to other star systems is also plausible. We have done this already on a small scale with the Pioneer plaques, the Voyager records, and the Arecibo radio message sent to the globular star cluster Messier 13 in 1974. Our microwave leakage might also be considered cultural preservation on a galactic scale of a sort.”

THE KILLING STAR, by Charles Pellegrino and George Zebrowski,
BY Gerald Jonas  /  May 14, 1995

“The Killing Star is a novel of ideas — or, rather, of one big idea. Carl Sagan, among others in the scientific community, has argued that any intelligent forms of extra terrestrial life we encounter, either in space or here on Earth, are likely to be friendly, since overly aggressive species will most probably destroy themselves before they
become capable of interstellar travel or communication. Mr. Pellegrino and Mr. Zebrowski beg to differ. They have embedded their rebuttal in a novel of such conceptual ferocity and scientific plausibility that it amounts to a reinvention of that old Wellsian staple: Invading Monsters From Outer Space.

In painstaking detail, the authors describe the annihilation of virtually all life on Earth by weapons expressly designed to “cleanse” human beings from the universe. The aliens responsible for this unprovoked attack do not think of themselves as monsters. They are not interested in stealing our land or our resources. Having deciphered the television broadcasts we have so rashly been transmitting to the stars for the last 50 years, they feel it only prudent to destroy us before we have a chance to destroy them. With an objectivity that gives new meaning to the phrase sub specie aeternitatis, the authors present the aliens’ view as a perfectly reasonable act of pre-emptive defense.

If you imagine that this scenario makes for a grim tale, you are right. But without deviating from their appointed task, Mr. Pellegrino and Mr. Zebrowski manage to find a number of bright spots. Here and there — in a submarine exploring the wreck of the Titanic on the ocean floor and in a few space stations and interplanetary vessels — isolated pockets of human beings survive the first assault. However, even these are relentlessly hunted down by automated alien weaponry. The survivors are rooted out and exterminated.

Despite a style that mimics the cool detachment of scientific writing — “Microdiamonds fell out of the cloud, little industrial-grade needles of compressed carbon. They were all that remained of Vinny, Sharon, Lenny and Robyn” — the authors wring a surprising amount of suspense from their resolution of the overriding question: Who will escape to carry on the species and to wreak a little reasonable revenge on the perpetrators?”


“Radio astronomy on the Moon in 2021 reveals the presence of life by a nearby red dwarf, on a tide-locked planet. To investigate them and the message they are transmitting, Earth’s governments confiscate the Lancer (a large colonization ship based on a crashed alien ship discovered in the Mare Marginis) and send it to investigate. In 2061, it arrives and discovers a primitive biological race of nomads broadcasting en masse with organs adapted to emit and receive electromagnetic radiation; their transmissions was blurred by various nomads falling out of synch with the rest. Close up, the transmission is discovered to be an old radio show from the 1950s – the signal the EMs (as they are called) consider best to reply to Earth with.”


“These berserkers, a doomsday weapon left over from an interstellar war 50,000 years ago, are killer spaceships furnished with machine intelligence, operating from asteroid-sized berserker bases where they are capable of building more Berserkers and auxiliary machines. The name is a reference to the human “Berserkers”, warriors of Norse legend. The Berserker stories (published as novels and short stories) describe humanity’s fight against the berserkers. The term “humanity” refers to all sentient life in the Galaxy, emphasizing the common threat the berserkers pose toward all forms of life. Homo sapiens, referred to as Earth-descended or ED humans, or as Solarians, are the only sentient species aggressive enough to put up a fight.”


BY Terry Bisson

(From OMNI, April 1991. This story, which was a 1991 Nebula nominee, has been appearing around the internet lately without my name attached. Several people were kind enough to alert me, but the truth is I’m more flattered than offended. )

“They’re made out of meat.”


“Meat. They’re made out of meat.”


“There’s no doubt about it. We picked up several from different parts of the planet, took them aboard our recon vessels, and probed them all the way through. They’re completely meat.”

“That’s impossible. What about the radio signals? The messages to the stars?”

“They use the radio waves to talk, but the signals don’t come from them. The signals come from machines.”

“So who made the machines? That’s who we want to contact.”

“They made the machines. That’s what I’m trying to tell you. Meat made the machines.”

“That’s ridiculous. How can meat make a machine? You’re asking me to believe in sentient meat.”

“I’m not asking you, I’m telling you. These creatures are the only sentient race in that sector and they’re made out of meat.”

“Maybe they’re like the orfolei. You know, a carbon-based intelligence that goes through a meat stage.”

“Nope. They’re born meat and they die meat. We studied them for several of their life spans, which didn’t take long. Do you have any idea what’s the life span of meat?”

“Spare me. Okay, maybe they’re only part meat. You know, like the weddilei. A meat head with an electron plasma brain inside.”

“Nope. We thought of that, since they do have meat heads, like the weddilei. But I told you, we probed them. They’re meat all the way through.”

“No brain?”

“Oh, there’s a brain all right. It’s just that the brain is made out of meat! That’s what I’ve been trying to tell you.”

“So … what does the thinking?”

“You’re not understanding, are you? You’re refusing to deal with what I’m telling you. The brain does the thinking. The meat.”

“Thinking meat! You’re asking me to believe in thinking meat!”

“Yes, thinking meat! Conscious meat! Loving meat. Dreaming meat. The meat is the whole deal!  Are you beginning to get the picture or do I have to start all over?”

“Omigod. You’re serious then. They’re made out of meat.”

“Thank you. Finally. Yes. They are indeed made out of meat. And they’ve been trying to get in touch with us for almost a hundred of their years.”

“Omigod. So what does this meat have in mind?”

“First it wants to talk to us. Then I imagine it wants to explore the Universe, contact other sentiences, swap ideas and information. The usual.”

“We’re supposed to talk to meat.”

“That’s the idea. That’s the message they’re sending out by radio. ‘Hello. Anyone out there. Anybody home.’ That sort of thing.”

“They actually do talk, then. They use words, ideas, concepts?”

“Oh, yes. Except they do it with meat.”

“I thought you just told me they used radio.”

“They do, but what do you think is on the radio? Meat sounds. You know how when you slap or flap meat, it makes a noise? They talk by flapping their meat at each other. They can even sing by squirting air through their meat.”

“Omigod. Singing meat. This is altogether too much. So what do you advise?”

“Officially or unofficially?”


“Officially, we are required to contact, welcome and log in any and all sentient races or multibeings in this quadrant of the Universe, without prejudice, fear or favor. Unofficially, I advise that we erase the records and forget the whole thing.”

“I was hoping you would say that.”

“It seems harsh, but there is a limit. Do we really want to make contact with meat?”

“I agree one hundred percent. What’s there to say? ‘Hello, meat. How’s it going?’ But will this work? How many planets are we dealing with here?”

“Just one. They can travel to other planets in special meat containers, but they can’t live on them. And being meat, they can only travel through C space. Which limits them to the speed of light and makes the possibility of their ever making contact pretty slim. Infinitesimal, in fact.”

“So we just pretend there’s no one home in the Universe.”

“That’s it.”

“Cruel. But you said it yourself, who wants to meet meat? And the ones who have been aboard our vessels, the ones you probed? You’re sure they won’t remember?”

“They’ll be considered crackpots if they do. We went into their heads and smoothed out their meat so that we’re just a dream to them.”

“A dream to meat! How strangely appropriate, that we should be meat’s dream.”

“And we marked the entire sector unoccupied.”

“Good. Agreed, officially and unofficially. Case closed. Any others? Anyone interesting on that side of the galaxy?”

“Yes, a rather shy but sweet hydrogen core cluster intelligence in a class nine star in G445 zone. Was in contact two galactic rotations ago, wants to be friendly again.”

“They always come around.”

“And why not? Imagine how unbearably, how unutterably cold the Universe would be if one were all alone …”


“Dr. Seth Shostak of the SETI Institute discusses some of the most basic issues behind listening for signals from advanced civilizations in the vast sea of space.”

Q. Why doesn’t SETI transmit?
A. It’s not for paranoid reasons… not because someone’s afraid that if we make our presence known, the aliens will come to Earth to steal our chlorophyll or our women. After all, I Love Lucy is already announcing our presence to neighborhood extraterrestrials. The reason we don’t broadcast is far simpler. Suppose the nearest
civilization is 100 light-years away (not so far, astronomically speaking). Our “message” would take 100 years to get to the aliens, and if they deign to reply, their answer would take another 100 years to make the return trip to Earth. Total elapsed time: two centuries. By that time, all the scientists involved with the project will have
lost interest and, probably, funding!

Q. So how many star systems has I Love Lucy already reached?
A. I Love Lucy was popular in the fifties, so the earliest shows have travelled 40 light-years into space. There are about 100 stars within that distance, and if there are any inhabited planets encircling these nearby stellar sites, they might be watching Lucy and Desi if they’ve bothered to build a very large antenna capable of
working at the relatively low broadcast frequencies of television (about 100 MHz).

Q. How powerful would the aliens’ transmitters have to be in order for us to hear them?
A. This depends on two things: how far away are the extraterrestrials, and how large a transmitting antenna are they using? As a typical example, suppose the nearest cosmic civilization is 100 light-years distant (there are about a thousand stars within that distance, incidentally). And further suppose that their transmitting antenna is comparable in size to the antennas we use for receiving — for SETI — here on Earth, a few hundred feet in diameter. Then they would need a 500,000-watt transmitter for us to hear their call. That’s not very much; there are radars and TV stations that burn up that many kilowatts here on Earth.

Q. Would the aliens be friendly?
A. Obviously no one knows the answer to this. If we pick up a signal from an alien society, that civilization will almost surely be far in advance of our own. They will presumably have survived the aggressive instincts in their own society, and may have a benevolent view towards others. On the other hand, aliens that undertake interstellar travel and land in our backyard might be of a different sort. The history of such expeditions on Earth has always been that it is better to be the visitor than the visitee. Consider the Indians of North and South America; their societies didn’t survive contact with the Europeans, even in those few instances when the latter weren’t deliberately malicious.

Q. Why would any real, detected extraterrestrials be much more advanced then the familiar aliens from sci-fi films?
A. We won’t hear anything from aliens that are less technically advanced than we are, that’s obvious. But what are the chances that they have just invented radio in the past 100 years, as we have? That’s highly unlikely. It would be like getting on the freeway and finding that the first car that passes you has the same license plate number as your own, except incremented in the last digit. It could happen, but most probably won’t. Any aliens we overhear will be thousands to millions of years more advanced than our own civilization.

Q. Could we ever understand anything we pick up? If so, could we short-circuit a million years of history, and leap into the future?
A. If the aliens are sending deliberate broadcasts for the benefit of emerging societies, such as ours, then they will make the messages easy to understand. In that case, we might grasp their meaning. If, on the other hand, we merely happen to “eavesdrop” on internal traffic, there’s little chance we’ll ever be able to make anything of it. It would be like giving a Neanderthal the output from your modem. He might have considerable cranial capacity, but he’d never understand a bit of it!

Q. What about UFOs? Are the aliens already here? Or stacked up somewhere by the government?
A. The answer is no. This would be the biggest science story of the millennium. If scientists thought there was even the slightest chance that this was true, thousands of them would be working on the problem. They’re not!



FROM: Alexander L. Zaitsev
date Thu, Feb 14, 2008 at 4:15 AM

Dear Colleague,

I am Dr. Alexander Zaitsev, IRE, Russia.

Just now I detected and read your post ” IF THEY’VE BOTHERED” with great interest and would like to make only two notes:

1) In Aug-Sep 2001 we transmitted the TAM not one, but SIX times to the six nearest Sun-like stars, see, for example:

2) Also, in the sentence:

Now, after a long period when there were no deliberate transmissions into space, a new round is about to take place and more are planned. A team led by the astronomer Alexander Zaitsev has already beamed forth a series of interstellar messages, including pictorial and musical transmissions, from the Evpatoria radio telescope in the Ukraine. was established a fact that the TAM was the world-first musical IRM (Interstellar Radio Message). Therefore, the NASA Beatles Transmission was the second musical IRM and all NASA’s declaration:

about theirs palm of supremacy in music to space transmission is not correct.

With best regards,
Dr. Alexander L. Zaitsev, IRE, Russia

From the archive, originally posted by: [ spectre ]


Public release date: 14-Aug-2007

Contact: Charlie Wallace
charlie [dot] wallace [at] iop [dot] org

Physicists discover inorganic dust with lifelike qualities

Could extraterrestrial life be made of corkscrew-shaped particles of
interstellar dust? Intriguing new evidence of life-like structures
that form from inorganic substances in space are revealed today in the
New Journal of Physics. The findings hint at the possibility that life
beyond earth may not necessarily use carbon-based molecules as its
building blocks. They also point to a possible new explanation for the
origin of life on earth.

Life on earth is organic. It is composed of organic molecules, which
are simply the compounds of carbon, excluding carbonates and carbon
dioxide. The idea that particles of inorganic dust may take on a life
of their own is nothing short of alien, going beyond the silicon-based
life forms favoured by some science fiction stories.

Now, an international team has discovered that under the right
conditions, particles of inorganic dust can become organised into
helical structures. These structures can then interact with each other
in ways that are usually associated with organic compounds and life

V.N. Tsytovich of the General Physics Institute, Russian Academy of
Science, in Moscow, working with colleagues there and at the Max-
Planck Institute for Extraterrestrial Physics in Garching, Germany and
the University of Sydney, Australia, has studied the behaviour of
complex mixtures of inorganic materials in a plasma. Plasma is
essentially the fourth state of matter beyond solid, liquid and gas,
in which electrons are torn from atoms leaving behind a miasma of
charged particles.

Until now, physicists assumed that there could be little organisation
in such a cloud of particles. However, Tsytovich and his colleagues
demonstrated, using a computer model of molecular dynamics, that
particles in a plasma can undergo self-organization as electronic
charges become separated and the plasma becomes polarized. This effect
results in microscopic strands of solid particles that twist into
corkscrew shapes, or helical structures. These helical strands are
themselves electronically charged and are attracted to each other.

Quite bizarrely, not only do these helical strands interact in a
counterintuitive way in which like can attract like, but they also
undergo changes that are normally associated with biological
molecules, such as DNA and proteins, say the researchers. They can,
for instance, divide, or bifurcate, to form two copies of the original
structure. These new structures can also interact to induce changes in
their neighbours and they can even evolve into yet more structures as
less stable ones break down, leaving behind only the fittest
structures in the plasma.

So, could helical clusters formed from interstellar dust be somehow
alive? “These complex, self-organized plasma structures exhibit all
the necessary properties to qualify them as candidates for inorganic
living matter,” says Tsytovich, “they are autonomous, they reproduce
and they evolve”.

He adds that the plasma conditions needed to form these helical
structures are common in outer space. However, plasmas can also form
under more down to earth conditions such as the point of a lightning
strike. The researchers hint that perhaps an inorganic form of life
emerged on the primordial earth, which then acted as the template for
the more familiar organic molecules we know today.

New J. Phys. 9 (2007) 263
PII: S1367-2630(07)48657-8

From plasma crystals and helical structures towards inorganic living

V N Tsytovich1,5, G E Morfill2, V E Fortov3, N G Gusein-Zade1, B A
Klumov2 and S V Vladimirov4

1 General Physics Institute, Russian Academy of Science, Vavilova str.
38, Moscow, 119991, Russia
2 Max-Planck-Institut für Extraterrestrische Physik, 85740 Garching,
3 Insitute of Physics of Extremal State of Matter, Russian Academy of
Science, Moscow, Russia
4 School of Physics, The University of Sydney, NSW 2006, Australia

5 Author to whom any correspondence should be addressed.

E-mail: tsyto [at] mpe [dot] mpg [dot] de

Received 19 April 2007
Published 14 August 2007

Abstract. Complex plasmas may naturally self-organize themselves into
stable interacting helical structures that exhibit features normally
attributed to organic living matter. The self-organization is based on
non-trivial physical mechanisms of plasma interactions involving over-
screening of plasma polarization. As a result, each helical string
composed of solid microparticles is topologically and dynamically
controlled by plasma fluxes leading to particle charging and over-
screening, the latter providing attraction even among helical strings
of the same charge sign. These interacting complex structures exhibit
thermodynamic and evolutionary features thought to be peculiar only to
living matter such as bifurcations that serve as `memory marks’, self-
duplication, metabolic rates in a thermodynamically open system, and
non-Hamiltonian dynamics. We examine the salient features of this new
complex `state of soft matter’ in light of the autonomy, evolution,
progenity and autopoiesis principles used to define life. It is
concluded that complex self-organized plasma structures exhibit all
the necessary properties to qualify them as candidates for inorganic
living matter that may exist in space provided certain conditions
allow them to evolve naturally.


* 1. Introduction
* 2. Plasma over-screening and plasma fluxes
* 3. Helical dust structures
* 4. Replication of helical dust structures
* Acknowledgment
* Appendix
o A.1. Methods used for description of plasma crystal
o A.2. Numerical simulation methods
* References

1. Introduction

A universal definition of life [1] relates it to autonomy and open-
ended evolution [2], i.e. to autonomous systems with open-ended
evolution/self-organization capacities. Thus a number of features
follow: some energy transduction apparatus (to ensure energy current/
flow); a permeable active boundary (membrane); two types of
functionally interdependent macromolecular components (catalysts and
records)–in order to articulate a `genotype-phenotype’ decoupling
allowing for an open-ended increase in the complexity of the
individual agents (individual and `collective’ evolution) [3]. The
energy transduction system is necessary to `feed’ the structure; the
boundary as well as a property called `autopoiesis’ (which is a
fundamental complementarity between the structure and function [4, 5])
are necessary to sustain organized states of dissipative structures
stable for a long period of time. To maintain a living organic state,
it is also necessary to process nutrients into the required
biochemical tools and structures through metabolism which in
mathematical terms can be seen as a mapping f that transforms one
metabolic configuration into another (and is invertible) f(f) = f;
i.e. it is a function that acts on an instance of itself to produce
another instance of itself [6, 7]. Finally, memory and reproduction of
organic life are based on the properties of DNA which are negatively
charged macromolecules exhibiting an important property of replication

Self-organization of any structure needs energy sources and sinks in
order to decrease the entropy locally. Dissipation usually serves as a
sink, while external sources (such as radiation of the Sun for organic
life) provide the energy input. Furthermore, memory and reproduction
are necessary for a self-organizing dissipative structure to form a
`living material’. The well known problem in explaining the origin of
life is that the complexity of living creatures is so high that the
time necessary to form the simplest organic living structure is too
large compared to the age of the Earth. Similarly, the age of the
Universe is also not sufficient for organic life to be created in a
distant environment (similar to that on the Earth) and then
transferred to the Earth.

Can faster evolution rates be achieved for non-organic structures, in
particular, in space consisting mostly of plasmas and dust grains,
i.e. of natural components spread almost everywhere in the Universe?
If yes, then the question to address is: are the above necessary
requirements of self-organization into a kind of a `living creature’
present in plasmas containing macro-particles such as dust grains?
Here, we discuss new aspects of the physics of dust self-organization
that can proceed very fast and present an explanation of the grain
condensation into highly organized structures first observed as plasma
crystals in [9, 10]. We stress that, previously, important features of
these structures were not clearly related to their peculiar physics
such as plasma fluxes on to grain surfaces, sharp structural
boundaries, and bifurcations in particle arrangements that can serve
as memory marks and help reproduction. The plasma fluxes strongly
influence interactions of dust particles, sustain the boundaries, and
realize the energy transduction. We discuss experiments which indicate
the natural existence of the memory marks in helical dust structures,
similar to DNA, and natural mechanisms of the helical dust structure

2. Plasma over-screening and plasma fluxes

An important feature of inorganic structures is the presence of
`memory marks’ existing as `rigid marks’ in common crystal systems. In
contrast, observations of crystals formed by dust in a plasma (plasma
crystals) [9, 10] demonstrate no rigid marks because of unusual
properties of plasma crystals such as large coupling constant, low
temperature of phase transition, and large separation of grains. These
puzzling properties can be resolved by employing the over-screening of
grain fields, the effect that was clearly realized only recently. The
over-screening appears in the presence of plasma fluxes on to the
grain surfaces [11]-[13]. As a result, an attraction well appears as
indicated schematically in figure 1. This potential well is usually
shallow and located at a distance much larger than the Debye screening
length λD (an example shown in figure 1 uses parameters typical for
plasma crystal experiments [9, 10]). A shallow potential well explains
the large coupling constant as well as the low temperature of phase
transitions. By extracting the pure Coulomb potential of interaction
and introducing the screening factor ψ, the grain interaction
potential is V = Zd2e2ψ/r (Zd is the grain charge in units of electron
charge -e). Due to over-screening, the value of ψ changes its sign at
large distances as indicated in figure 1. At the potential well
minimum, the screening factor ψmin is negative. The value |ψmin|
determines the temperature of the associated phase transition Td and
also characterizes the distance rd = rd(|ψmin|) of the well minimum
(in the simplest case, r_{\rm d}\approx 1/\sqrt{\vert\psi_{\rm min}
\vert} ). If condensation of grains (or grain pairing) occurs, the
grains will be localized at the minimum of the attraction well, rd.
The corresponding criterion can be expressed through the coupling
constant Γ (which is the ratio of the potential energy of the grain
interaction to their kinetic energy) as Γ > Γcr≡Zd2e2/rdTd = 1/|ψmin|.
Thus, |ψmin| determines values of the inter-grain distance, the
temperature of transition, and the coupling constant. For a shallow
attractive well, |ψmin| ll 1 and Γ gg 1. This qualitatively explains
thelarge value of Γ observed in experiments. The model predicts Γcr to
be of the order of the difference between the maximum grain
interaction and the temperature of transition (about 3-4 orders of
magnitude). As a result, the concept of plasma over-screening agrees
well [12, 13] with major experimental observations [9, 10]. It also
applies for description of dust helical structures and leads to the
possibility of unusual `memory marks’ impossible in common crystals.

Figure 1

Figure 1. Sketch of the screening factor ψ of the grain interaction
potential. The grain interaction energy V can be described in units of
pure (not screened) Coulomb interactions of grains V = ψ(Zd2e2/r) as a
function of the distance between the grains in units of the linear
Debye screening length. The distance rd displays the position of the
minimum of the attraction well and has a typical experimental value of
200 μm [9, 10]. This corresponds to the inter-grain distances observed
during the phase transition to the plasma crystal state. The value of |
ψmin| varies between 10-2 and 10-4 for different models and different
experiments. This value is in accordance with the ratio of the
interaction at the minimum of the potential well and the maximum
interaction energy corresponding to ψ = 1, respectively. The value of
coupling constant Γ = 1/|ψmin| ranges from 102 up to 104 in accordance
with observations.

We have performed molecular dynamics simulations to demonstrate that a
random distribution of grains, interacting via the potential shown in
figure 1 with a shallow attractive well |ψmin|approx10-3 and
experiencing background friction and stochastic kicks, forms spherical
grain crystals. In figure 2, we show results of these simulations.
Application of this model is of double importance. Firstly, we resolve
the problems of laboratory observations, and secondly, we predict the
possible existence of large plasma poly-crystals in space–a new state
of matter which is unexplored so far. Here, an important point for
space applications is that the attraction potential well is shallow
and therefore even weak dissipation can cause the grain capture in the

Figure 2

Figure 2. Molecular dynamics simulations of dusty cloud evolution. The
figure shows snapshots of the velocity field and grain positions: (a)
corresponds to the initial state (t = 0) of the cloud, (b) t = 0.3 s
and (c) t = 3 s, respectively. The velocity magnitude is color-coded.
It rises from blue to red by a factor of five. Initially, 103μ m-size
grains were distributed randomly over the sphere of radius about rd
(see figure 1) and the pair interactions between grains are described
by the potential shown in figure 1. Grain motions are damped by
friction (to model viscosity of plasma neutral component) and
stochastically accelerated by Langevin force (to model plasma
fluctuations). The simulations reveal formation of a stable self-
confined spherical structure in time. Local order analysis shows that
some grains (about a few percents of their total number) have hcp
lattice type, while the majority of grains are in a liquid state.

Physically, the attraction appears due to the electrostatic self-
energy of grains, supported by plasma fluxes continuously absorbed by
the grains. The fluxes are necessary to sustain the grain charges and
appear almost immediately as soon as a particle is embedded in the
plasma. The self-energy of grains is much larger than their kinetic
and potential energies so that its (even small) changes can strongly
influence grain interactions. It was first shown in [11] that for a
fixed source of plasma fluxes, the electrostatic energy of two grains
decreases when they approach each other. As the self-energy is
supported by continuous plasma fluxes, work has to be done to maintain
them and this can almost compensate the associated changes of self-
energy. Nevertheless, a full compensation does not occur if the
distance between the grains is large. At present it is understood [12,
13] that this phenomenon is a general feature of grain interactions in
a plasma. The fluxes on grains depend on the electrostatic
polarization charges of the grains and the polarization charges depend
on the fluxes and create an accumulation of excess plasma charges
between the grains. These plasma charges exhibit the sign opposite to
that of likely charged interacting grains and therefore cause the
attraction. The appearance of grain attraction is a general phenomenon
which converts the grain containing matter into a new unusual state.

Effects of plasma fluxes lead to gravitation-like instabilities with
an effective gravitational constant GeffapproxZd2e2|ψminmd2. For a
dust size aapprox3 μm, a mass density of the dust material of 2g cm-2,
Zdapprox103 and |ψmin|approx10-4, the effective gravitational constant
Geff is approximately 6×104 cgs which is 1012 times larger than the
usual gravitational constant G = 6.7×10-8 cqs. The effective Jeans
length of this instability has the size of order rd. The effective
gravity affects only dust grains and therefore plasmas can be
influenced by this attraction only through their interactions with the
grains. The new effective instability of a dusty plasma leads to
structurization of dust clouds similar to the effects caused by the
usual gravitational instability.

Dust structures self-organized in the plasma environment have sharp
boundaries such that they are isolated from each other by regions
without grains (dust voids). This effect, observed in the laboratory
as well as in micro-gravity experiments onboard the ISS [14], is well
explained theoretically [15, 16]. The structures and crystals should
self-generate additional confining forces due to the plasma fluxes
directed into the structures, i.e. these structures serve as sinks of
plasmas and the ram pressure of the plasma fluxes acts on the
structures to make them self-organized, self-confined and dissipative.
This self-contraction should be added to the the grain pairing; their
joint effect leads to formation of dust helical structures.

3. Helical dust structures

Helical dust structures (an example is given in figure 3(a)), can be
considered as equally separated flat structures with constant rotation
angle between the planes (figure 3(b)). Their properties are of
special interest for the problems discussed here. Figure 3(a)
illustrates double helical dust structures similar to DNA. Molecular
dynamics simulations of interacting grains with an additional gas
friction show that any cylindrically symmetric grain distribution
converts in time into a stable self-confined helical structure [17].
These specific stable dust structures form due to the grain pairing
attraction as well as due to the external plasma flux created by the
whole structures (and the anticipated ram pressure). In experiments in
gas discharges with a longitudinal external electric field forming
striations [18, 19], modulated cylindrical grain crystals were
observed. As predicted by numerical simulations [17], these
cylindrical crystals convert into helical structures with fewer grains
per unit length. According to numerical experiments, highly symmetric
spherical dust structures can be formed only when the spherical
symmetry is externally supported (e.g. when all initial conditions are
spherically symmetric). In the other cases, even a small asymmetry
leads to formation of cylindrically symmetric and/or helical
structures. In nature, some asymmetry always exists and therefore
formation of helical structures is quite probable. First observations
of dust self-confined moving helical structures were done in dc
cryogenic gas discharges [20]. The particle traces, moving in a self-
organized way, are shown in figure 4. Similar ion helical structures
were also observed in laser cooling traps [21].

Figure 3

Figure 3. (a) and (b) Sketch of helical double winding grain
structures similar to DNA. (c) Bifurcations in (phi,D/Δ)–plane of
structures confined by external potential Kr2/2; phi is the rotational
angle in each plane of the helical structure; D is the diameter of the
helical structure and Δ is the spatial separation of the planes of the
helical structure; the line K = 0 corresponds to self-organized stable
structures without external confinement K = 0 but with the presence of
dust attraction [17].

Figure 4

Figure 4. (a) Traces of helical structures on the walls of the chamber
observed in dc cryogenic plasmas at Ti = 2.7 K. The traces of conical
helical structure are shown black on the green background of discharge
at several distances from the top of it; x = 0 mm–the `head’ of the
structure, x = 3 mm–the middle of the structure and 5 mm–the end of
the structure. The whole structure looks like a `worm’, hollow inside
(having a dust void inside) and moving on cylindrical surfaces around
the axis of discharge. (b) Sketch of the central part of the helical
structure of the `worm’ deduced from the traces left of the structure
on the wall of the discharge chamber, the grains are located at the
surfaces of a few cylinders inside each other [20].

Important features of dust helical structures observed in simulations
[17] and indicated by analytical investigation of stability of helical
structures and mode oscillations is the existence of numerous
bifurcations in the dependence of the helical winding angle upon the
diameter of the structure. An example of this helical structure
behavior is demonstrated schematically in figure 3(c). Bifurcations in
helical structures appear naturally and correspond to the critical
conditions when any slight change in the helical structure diameter D
results in a sudden change of the helical winding. We note that
various helical structures with different bifurcations can be obtained
in experiments using current cylindrical discharge plasma crystals by
continuously decreasing the number of grains injected into the system.
Numerical investigations show a universal character of these
bifurcations. The helical structures have the unique property of
bifurcations which can serve as memory marks. With increasing of
diameter of the structure suddenly the rotational angle of the
structure is changed. This is illustrated by figure 3(c) which shows
that an increase of diameter of the structure at certain radius there
appears possibility of presence of two equilibrium vales of the
rotational angle (the upper thick dashed line and the lower solid
line) instead of one possible equilibrium value for the rotational
angle before bifurcation (the upper thick line). After the bifurcation
the solid thick dashed line represents an unstable branch and the
solid lower line represents a stable branch. Thus the rotational angle
at some critical radius is changing abruptly.

These bifurcations can serve as possible memory marks for the
structures. The helical crystals can then store this information.

4. Replication of helical dust structures

Dust convection and dust vortex formation outside the structure is
another natural phenomenon observed in laboratory experiments and in
experiments onboard the ISS [14]-[16]. The physics of dust vortex
formation is related to the grain charge inhomogeneity and its
dependence on surrounding plasma parameters. The gradients of grain
charges are supported self-consistently by the structure, and they are
the reason for the non-potential character of the electrostatic force –
eZdE acting on the grains and causing the vortex formation. Dust
convection was observed in experiments on cylindrical dust crystals
formed in modulated gas discharges [18] (figure 5(a)) and was obtained
in numerical modeling [19] (figure 5(b)). It is important that the
helical crystals modulated in their radius are always surrounded by
self-created dust convection cells. The helical dust structures, after
they are formed, resemble features similar to those of DNA. In
particular, they can transfer information from one helical structure
to another via the dust convective cells surrounding any bifurcation
of the helical structure. A rough sketch of a possible model of the
helical grain structure reproduction is shown in figure 5(c).

Figure 5

Figure 5. (a) The observed grain convection surrounding the
cylindrical grain crystal. Different colors correspond to different
grain velocities [18], The velocities vary from about 0.4 cm s-1
(blue) up to 1.5 cm s-1 (red). (b) The dust convection obtained in
numerical simulations [19]. (c) Sketch of the model for helical
structure duplication (reproduction). See details in the text.

Let us discuss some details about possible sequences of events during
the reproduction. The abrupt change of the rotational angle will
create an inhomogeneity in random halo dust grains surrounding the
helical structure with grain charge gradient not collinear to the
electric field and will create a force forming pair of toroidal
vortices around the structure. For a negatively charged structure the
upper toroidal vortex has a clockwise rotation while the lower has an
anti-clockwise rotation. If another (second) helical structure has no
bifurcation and moves close to that with bifurcation the vortices
start to be created in this structure. Finally these vortices create
the bifurcation in the second structure and transfer the information
from the first structure to the other one.

The evolution of dust structures in the presence of plasma fluxes is
related to the characteristic frequency of dust motions. In first
instance, this can be estimated by the dust plasma frequency
ωpd~(Zd2e2/mdrd3)1/2, where md is the mass of a dust particle. We note
that characteristics of the potential well (located at rd) and
therefore the physics of plasma fluxes enter this expression via rd
and Zd. This consideration destroys one of the current myths in
astrophysics, namely, that the grain interaction is vanishing for
distances larger than the linear Debye screening radius. This is
obvious since inside the dust Jeans length (where the interactions are
still effective) many grains are present for most dust clouds in
space. For most situations, the plasma dust frequency of a few (or
even a fraction of) Hz leads to times extremely short compared to
typical astrophysical times. If grain structures exist in space, they
have collective modes of oscillations which in principle can be
detected as modulations of the infrared emission of different cosmic
sources. The effective Jeans size of dust clumping is in the range
that can be detected by the Spitzer telescope in observation of (the
closest to the Earth) formations of dust clouds around stars and star
outbursts preceding the formation of new planetary systems. The
program to measure low frequency regular modulations from dust clouds
with the effective structure sizes caused by the dust attraction
instability can be included in, e.g. the Spitzer telescope project.

Our analysis shows that if helical dust structures are formed in
space, they can have bifurcations as memory marks and duplicate each
other, and they would reveal a faster evolution rate by competing for
`food’ (surrounding plasma fluxes). These structures can have all
necessary features to form `inorganic life’. This should be taken into
account for formulation of a new SETI-like program based not only on
astrophysical observations but also on planned new laboratory
experiments, including those on the ISS. In the case of the success of
such a program one should be faced with the possibility of resolving
the low rate of evolution of organic life by investigating the
possibility that the inorganic life `invents’ the organic life.


This work was partially supported by the Australian Research Council.


A.1. Methods used for description of plasma crystal

Special methods have been developed to treat the plasma over-screening
for present experiments with large grain charges which cause the
screening to be nonlinear at short distances between the grains [9,
10]. The full nonlinear treatment of the screening polarization
charges and plasma fluxes is rather complicated [12]. The progress was
achieved on the basis of physical arguments showing that close to the
grains the influence of fluxes on polarization is small. Neglecting
the effect of fluxes the nonlinear screening was solved in [13] by
using the approach of [22]. Far from the grain the coupling of fluxes
and polarization charges became important but the polarization charge
became small and one can use the linear approach to find the coupling.
The matching method at the distances where the nonlinearity starts to
be weak have been applied successfully [13] to describe the nonlinear

A.2. Numerical simulation methods

The cooperative behavior of charged grains embedded in a plasma is due
to electrostatic coupling between the charged particles, which are
believed to interact via a potential which has both a repulsive and an
attractive short-range component. 3D molecular dynamics simulations
including electrostatic collisions between grains, neutral drag and
stochastic Langevin force were performed to simulate the evolution of
a dusty cloud. Free boundary conditions were used. To analyze the
local order of grains, we used the bond order parameter method [23].


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E-mail: tsyto [at] mpe [dot] mpg [dot] de


Dr. Namik G Gusein-zade
E-mail: namik [at] fpl [dot] gpi [dot] ru


Prof. Dr. Gregor E. Morfill
E-mail: gem [at] mpe [dot] mpg [dot] de

Email: klumov [at] cips [dot] mpg [dot] de


Vladimir E. Fortov
e-mail: fortov [at] ficp [dot] ac [dot] ru


Email: S [dot] Vladimirov [at] physics [dot] usyd [dot] edu [dot] au

RE: posted by [ jstark ]

From the archive, originally posted by: [ spectre ]

Looking for Life in All the Wrong Places
Weird space critters could be right beneath our planetary probes.

By Christen Brownlee

In 1976, scientists anxiously waited for the first data streaming back
from the Viking 1 and 2 landers, sent to search for signs of life on
Mars. The results were frustratingly inconclusive; for decades
researchers have been debating whether the Vikings detected life. Then
last January, two scientists presented a paper arguing that Mars may
indeed harbor life, but that the landers’ life-detecting equipment may
have killed it. They theorized that Martian microorganisms might
contain a mixture of water and hydrogen peroxide; if so, a Viking
experiment that doused Martian soil samples with water would have
drowned such life-forms.

The idea that Mars may harbor microbes containing hydrogen peroxide is
based in part on the presence of what appears to be that chemical on
Mars’ surface. The theory that microbes may be the origin of that
hydrogen peroxide is not well accepted-not yet, anyway. Most
researchers digging for extraterrestrial life are focused on forms
containing water and carbon-based molecules-the only forms found on
Earth. But a growing number of scientists are speculating that the
solar system may harbor what they call “weird life”-forms that contain
chemicals not traditionally associated with living organisms.

Thanks to the discovery of unusual creatures on Earth, such as
“extremophile” bacteria adapted to the extreme heat of underwater
thermal vents, most astrobiologists accept the possibility that life-
forms on other planets could have unfamiliar appearances or
adaptations. However, most still envision microbes filled with water
and carbon-based, or organic, molecules. It’s not unreasonable, says
David Grinspoon, astrobiology curator of the Denver Museum of Nature
and Science and formerly NASA’s principal investigator for exobiology
research. He points out that such compounds have been detected in
practically every corner of the universe that has been examined.

However, he and other researchers now suggest that an element other
than carbon may serve as the backbone for molecules essential to life-
forms on other planets. One proposed substitute is silicon, which
occupies a place on the periodic table directly under carbon. Vertical
rows on the table represent an element’s most basic behavior, so
carbon and silicon’s close positions suggest that one can be swapped
for another to form molecules with similar characteristics, says

Likewise, water isn’t the only solvent that life-forms could use to
enable necessary chemical reactions, says Dirk Schulze-Makuch of
Washington State University in Pullman, one of the scientists who
suggested that Viking may have killed Martian microbes. “Life and
environmental conditions on a planet are intrinsically related,” he
explains; he champions the idea of Martian organisms containing
hydrogen peroxide because it fits with the very cold and dry
conditions on that planet. Depending on its concentration in a
solution, hydrogen peroxide does not freeze until at -70 degrees
Fahrenheit, and when it does freeze, it does not form crystals, which
would destroy cells . And the compound absorbs even minute amounts of
water vapor from the atmosphere, which would benefit a water-dependent
organism in an extremely dry environment like Mars’.

Chemist Steven Benner of the University of Florida in
Gainesville suggests that the molecules that might make up weird life
and enable it to reproduce may differ from terrestrial proteins and
the nucleic acids DNA and RNA. By making some simple chemical tweaks
to these molecules, Benner and his colleagues have crafted new
variations that still work. “You can pick any one of these [molecules]
and easily walk away from its natural structure” while still
preserving functionality, he says. Benner and other researchers have
come up with a variety of new amino acids, the molecules that string
together to form proteins, that don’t exist in nature-at least not on
Earth. His group has also constructed new types of DNA with bases
different from the adenine, thymine, guanine, and cytosine that form
the rungs in the double helix on Earth.

The probes that search for life on other planets use technology that
can detect a range of chemicals beyond water and organic molecules.
The trick is to devise experimental protocols that do not destroy or
miss signs of possible life-a protocol, for example, that does not
douse samples with water if hydrogen peroxide is thought to be a
possible constituent. Recently, Rafael Navarro-Gonzalez of the
University of Mexico in Mexico City and others decided to check the
instrument that Viking used to test Martian soil for organic
molecules, a gas chromatograph-mass spectrometer (GCMS), which
identifies the atomic constituents of a substance. The scientists used
the instrument to test soils from areas on Earth that are similar to
Mars and known to have organic molecules, but it nonetheless gave
negative readings, again casting doubts on Viking’s results. Navarro-
Gonzalez says that the Mars Science Laboratory, presently planned to
launch in two years, will also use a GCMS, but it will follow a
different sample-treatment protocol, one that uses solvents, and is
more likely to reveal organic molecules, if any are present.

Another way to increase the chances for finding new life-forms is to
send probes to areas where they are more likely to be found-that is,
to search creatively. The Mars Science Laboratory will cover a much
greater area than Viking did. And NASA’s Phoenix probe, currently
scheduled to take off this August, will land in a subpolar area of
Mars that is especially cold and higher in atmospheric water vapor-
more favorable than the Viking sites for detecting life, especially
the hydrogen peroxide-containing organisms Schulze-Makuch envisions.
Phoenix will also carry non-chemical tests: two microscopes to study
samples for signs of life.

What’s the probability that life unlike anything we know is thriving
in extraterrestrial obscurity? “The chances that it might exist are
high, but the chances that we’re going to encounter it are probably
low,” says Benner. “Space is a big place.” To plan a search that has a
decent chance of finding whatever may be out there, we will need not
just technology but imagination.

“Fundamentally,” says David Grinspoon, “the universe is much more
creative than we are.”

By Cherie Winner, WSU News Service, 509/335-4846, ,
Washington State Magazine

Contact: Dirk Schulze-Makuch, WSU School of Earth and Environmental
Sciences, 509/335-1180,

New Analysis of Viking Mission Results Points to Possible Presence of
Life on Mars

PULLMAN, Wash. — We may already have ‘met’ Martian organisms,
according to a paper presented Sunday (Jan. 7) at the meeting of the
American Astronomical Society in Seattle.

Dirk Schulze-Makuch of Washington State University and Joop Houtkooper
of Justus-Liebig-University, Giessen, Germany, argue that even as new
missions to Mars seek evidence that the planet might once have
supported life, we already have data that may show life exists there
now-data from experiments done by the Viking Mars landers in the late

“I think the Viking results have been a little bit neglected in the
last 10 years or more,” said Schulze-Makuch. “But actually, we got a
lot of data there.” He said recent findings about Earth organisms that
live in extreme environments and improvements in our understanding of
conditions on Mars give astrobiologists new ways of looking at the 30-
year-old data.

The researchers hypothesize that Mars is home to microbe-like
organisms that use a mixture of water and hydrogen peroxide as their
internal fluid. Such a mixture would provide at least three clear
benefits to organisms in the cold, dry Martian environment, said
Schulze-Makuch. Its freezing point is as low as -56.5 C (depending on
the concentration of H2O2); below that temperature it becomes firm but
does not form cell-destroying crystals, as water ice does; and H2O2 is
hygroscopic, which means it attracts water vapor from the atmosphere-a
valuable trait on a planet where liquid water is rare.

Schulze-Makuch said that despite hydrogen peroxide’s reputation as a
powerful disinfectant, the fluid is also compatible with biological
processes if it is accompanied by stabilizing compounds that protect
cells from its harmful effects. It performs useful functions inside
cells of many terrestrial organisms, including mammals. Some soil
microbes tolerate high levels of H2O2 in their surroundings, and the
species Acetobacter peroxidans uses hydrogen peroxide in its

Possibly the most vivid use of hydrogen peroxide by an Earth organism
is performed by the bombardier beetle (Brachinus), which produces a
solution of 25 percent hydrogen peroxide in water as a defensive
spray. The noxious liquid shoots from a special chamber at the
beetle’s rear end when the beetle is threatened.

He said scientists working on the Viking projects weren’t looking for
organisms that rely on hydrogen peroxide, because at the time nobody
was aware that such organisms could exist. The study of extremophiles,
organisms that thrive in conditions of extreme temperatures or
chemical environments, has just taken off since the 90s, well after
the Viking experiments were conducted.

The researchers argue that hydrogen peroxide-containing organisms
could have produced almost all of the results observed in the Viking

Hydrogen peroxide is a powerful oxidant. When released from dying
cells, it would sharply lower the amount of organic material in their
surroundings. This would help explain why Viking’s gas chromatograph-
mass spectrometer detected no organic compounds on the surface of
Mars. This result has also been questioned recently by Rafael Navarro-
Gonzalez of the University of Mexico, who reported that similar
instruments and methodology are unable to detect organic compounds in
places on Earth, such as Antarctic dry valleys, where we know soil
microorganisms exist.

The Labeled Release experiment, in which samples of Martian soil (and
putative soil organisms) were exposed to water and a nutrient source
including radiolabeled carbon, showed rapid production of radiolabeled
CO2 which then leveled off. Schulze-Makuch said the initial increase
could have been due to metabolism by hydrogen peroxide-containing
organisms, and the leveling off could have been due to the organisms
dying from exposure to the experimental conditions. He said that point
has been argued for years by Gilbert Levin, who was a primary
investigator on the original Viking team. The new hypothesis explains
why the experimental conditions would have been fatal: microbes using
a water-hydrogen peroxide mixture would either “drown” or burst due to
water absorption, if suddenly exposed to liquid water.

The possibility that the tests killed the organisms they were looking
for is also consistent with the results of the Pyrolytic Release
experiment, in which radiolabeled CO2 was converted to organic
compounds by samples of Martian soil. Of the seven tests done, three
showed significant production of organic substances and one showed
much higher production. The variation could simply be due to patchy
distribution of microbes, said Schulze-Makuch. Perhaps most
interesting was that the sample with the lowest production-lower even
than the control-had been treated with liquid water.

The researchers acknowledge that their hypothesis requires further
exploration. “We might be mistaken,” said Schulze-Makuch. “But it’s a
consistent explanation that would explain the Viking results.”

He said the Phoenix mission to Mars, which is scheduled for launch in
August, 2007, offers a good chance to further explore their
hypothesis. Although the mission’s experiments were not designed with
peroxide -containing organisms in mind, Phoenix will land in a sub-
polar area, whose low temperatures and relatively high atmospheric
water vapor (from the nearby polar ice caps) should provide better
growing conditions for such microbes than the more “tropical” region
visited by Viking. Schulze-Makuch said the tests planned for the
mission, including the use of two microscopes to examine samples at
high magnification, could reveal whether we had the answer all along-
and if we’ve already introduced ourselves to our Martian neighbors in
a harsher way than we intended.

“If the hypothesis is true, it would mean that we killed the Martian
microbes during our first extraterrestrial contact, by drowning-due to
ignorance,” said Schulze-Makuch.

The limitations on organic detection in Mars-like soils by thermal
volatilization-gas chromatography-MS and their implications for the
Viking results

Rafael Navarro-González*,, Karina F. Navarro*, José de la Rosa*,
Enrique Iñiguez*, Paola Molina*, Luis D. Miranda, Pedro Morales, Edith
Cienfuegos, Patrice Coll¶, François Raulin¶, Ricardo Amils||, and
Christopher P. McKay**

*Laboratorio de Química de Plasmas y Estudios Planetarios, Instituto
de Ciencias Nucleares, and Institutos de Química and Geología,
Universidad Nacional Autónoma de México, Circuito Exterior, Ciudad
Universitaria, P.O. Box 70-543, 04510 México D.F., Mexico;
¶Laboratoire Interuniversitaire des Systèmes Atmosphériques, Unité
Mixte de Recherche 7583, Centre National de la Recherche Scientifique,
Université Paris 12-Val de Marne and Université Paris 7-Denis Diderot,
61 Avenue du Général de Gaulle 94010, Créteil Cedex, France; ||Centro
de Astrobiología, Consejo Superior de Investigaciones Científicas/
Instituto Nacional de Tecnica Aeroespacial, Torrejón de Ardoz, 28850
Madrid, Spain; and **Space Science Division, Ames Research Center,
National Aeronautics and Space Administration, Moffett Field, CA

Edited by Leslie Orgel, The Salk Institute for Biological Studies, La
Jolla, CA, and approved September 11, 2006 (received for review May
21, 2006)

The failure of Viking Lander thermal volatilization (TV) (without or
with thermal degradation)-gas chromatography (GC)-MS experiments to
detect organics suggests chemical rather than biological
interpretations for the reactivity of the martian soil. Here, we
report that TV-GC-MS may be blind to low levels of organics on Mars. A
comparison between TV-GC-MS and total organics has been conducted for
a variety of Mars analog soils. In the Antarctic Dry Valleys and the
Atacama and Libyan Deserts we find 10-90 µg of refractory or graphitic
carbon per gram of soil, which would have been undetectable by the
Viking TV-GC-MS. In iron-containing soils (jarosites from Rio Tinto
and Panoche Valley) and the Mars simulant (palogonite), oxidation of
the organic material to carbon dioxide (CO2) by iron oxides and/or
their salts drastically attenuates the detection of organics. The
release of 50-700 ppm of CO2 by TV-GC-MS in the Viking analysis may
indicate that an oxidation of organic material took place. Therefore,
the martian surface could have several orders of magnitude more
organics than the stated Viking detection limit. Because of the
simplicity of sample handling, TV-GC-MS is still considered the
standard method for organic detection on future Mars missions. We
suggest that the design of future organic instruments for Mars should
include other methods to be able to detect extinct and/or extant

In 1976, the Viking Landers carried out an extensive set of biological
experiments to search for the presence of extant life on the surface
of Mars (1). In addition, a series of molecular analysis experiments
were conducted to search for the presence of organic compounds in the
martian soil (2). The biological tests consisted of three independent
experiments designed to detect Earth-like microorganisms in the top
few centimeters of the martian soil. The gas exchange experiment was
designed to determine whether martian life could metabolize and
exchange gaseous products in the presence of water vapor and in a
nutrient solution (3); the carbon assimilation experiment was based on
the assumption that martian life would have the capability to
incorporate radioactively labeled carbon dioxide and/or monoxide in
the presence of sunlight (i.e., photosynthesis) (4); and the labeled
release (LR) experiment sought to detect heterotrophic metabolism by
the release of radioactively labeled carbon initially incorporated
into organic compounds in a nutrient solution (5). At both Viking
landing sites the three biological experiments yielded positive
responses demonstrating the presence of a highly reactive soil.
Surprisingly, the LR experiment was suggestive of the possible
presence of biological activity in the martian soil. However, the most
puzzling result came from the molecular analysis experiments (2, 6)
performed in the martian soil: three sample analyses from surface
material from the Viking 1 and 2 sites and another from underneath a
rock from the Viking 2 site. In these experiments, soil was subjected
to thermal volatilization (TV)-gas chromatography (GC)-MS; this assay
consisted of a rapid heating of the soil to vaporize small molecules
and break down larger ones into smaller organic molecules, and the
resultant fragments were separated by GC and analyzed by MS.
Unexpectedly, in none of the experiments performed in both landing
sites could organic material be observed at detection limits generally
of the order of parts per billion for molecules larger than two carbon
atoms and of parts per million for some smaller molecules. The
evolution of CO2 and H2O, but not of other inorganic gases, was
observed upon heating the soil sample at 200°C, 350°C, and 500°C. One
important concern was whether the GC-MS instrument worked properly.
Fortunately, experimental data existed that demonstrated the proper
function of the instrument beyond any doubt (7). Traces of some
organic solvents that were used during the cleaning of the instruments
before they were incorporated into the Landers were detected in the
background, such as methyl chloride (15 parts per billion) and
perfluoroethers (1-50 parts per billion). These contaminants were
previously detected in preflight and cruise tests. Therefore, the
detection of these contaminants demonstrated that the instruments
worked well. Consequently, the presence of life in the martian soil
was in apparent contradiction with the results from the TV-GC-MS. The
lack of organics in the TV-GC-MS experiment was used as the most
compelling argument against the presence of extant life on the surface
of Mars.

The reactivity of the martian soil observed in the three biological
experiments (3-5) was subsequently explained by the presence of one or
more inorganic oxidants (e.g., superoxides, peroxides, and
peroxynitrates) at the parts per million level. The lack of organics
in the martian soil could also be explained by their oxidation to
carbon dioxide due to the presence of such oxidants and/or direct UV
radiation damage (8). There have been many suggestions regarding the
nature of the chemical reactivity of the martian soil, but no
laboratory experiment has yet been able to simulate both the gas
exchange (3) and the LR response (5). Instruments built to further
investigate the reactive nature of the martian soil [e.g., Mars
Oxidant Experiment for the ill-fated Russian Mars 1996 mission (8) and
Mars Oxidant Instrument for the European Space Agency ExoMars 2011
(9)] have not yet performed in situ experiments on Mars. Mars Oxidant
Instrument has been successfully tested in the Mars-like soils of the
Atacama Desert, where the oxidative nature of the soil is thought to
be triggered by strong acids (e.g., sulfuric and nitric acids)
depositing from the atmosphere (9).

A recent evaluation of the oxidative destruction mechanisms of
meteoritic organics on the surface of Mars suggests that the end
products are salts of aliphatic and aromatic polycarboxylic acids
(10). Such compounds are refractory organics (e.g., nonvolatile and
thermally stable) under the temperatures reached by the molecular
analysis experiments, and consequently they were missed by the Viking
TV-GC-MS (10). Alternatively, the absence of organics in the soil at
parts per billion levels does not preclude the presence of extant life
in the martian surface. Klein (11) pointed out that the Viking TV-GC-
MS would not detect Escherichia coli at levels of 106 per gram, which
has been confirmed by recent simulations (12).

The search for organics on Mars continues to be a key science goal for
future missions. Because of the simplicity of sample handling, TV-GC-
MS has still been considered the standard method for organic detection
on Mars; for instance, the ill-fated Beagle Lander carried a
combustion-MS, the Thermal Evolved Gas Analyzer instrument on the 2007
Phoenix mission is a thermal analysis and MS, the basic unit on the
Sample Analysis at Mars instrument selected for the upcoming 2009 Mars
Science Laboratory mission is a TV-GC-MS, and the Mars Organic
Detector unit for the 2011 European Space Agency ExoMars mission is a
TV coupled to capillary electrophoresis with a fluorescence detector.
We report here results of studies on several Mars analog soils in
which we compare the detection of organics by TV-GC-MS with total
organic analysis of the samples. We analyzed samples from the dry Mars-
like environments of the Dry Valleys in Antarctica (13) and the
Atacama Desert (14) in Chile and Peru, where environmental conditions
result in soils with low biological and organic content, and the
Libyan Desert in Egypt, which is part of the hyperarid Sahara. For
comparison, we also analyzed samples from wetter desert areas in the
Atacama and Mojave (in the southwestern U.S.) Deserts. We also
analyzed samples of jarosite-containing soils from the Rio Tinto in
Spain (15) and the Panoche Valley in California (16). These soils may
be analogs for the soils detected by the Mars exploration rover at the
Meridiani Planum site on Mars (17). In addition, we analyzed samples
of the National Aeronautics and Space Administration (NASA) Mars-1
martian soil simulant, which is derived from Hawaiian palagonite

Results and Discussion
All samples were analyzed for total organic matter, 13C, C/N ratio,
and their response in TV-GC-MS at 500°C (Viking protocol) and 750°C. A
summary of the results is listed in Table 1. The total organic matter
varied from 10 to 1,500 µg of C per gram of soil depending on the
environment. In all cases, the 13C values varied from -28.93 to –
20.06, a typical range for organic matter produced by C3
photosynthesis (19). Similarly, the C/N ratio for most samples is
typical of soil organic matter, 9-30 (20), except in Antarctica and La
Joya, where the ratio is 1. Surprisingly, the production of benzene, a
major organic compound resulting from TV-GC-MS was not correlated with
the amount of organic matter present originally in the soil. The
samples from the Dry Valleys of Antarctica (cold desert) and the arid
core regions of the Atacama (temperate desert) and the Libyan (hot
desert) contain very low levels of organics from 20 to 90 µg of C per
gram of soil. Antarctic sample 726 is of particular interest because
it was one of the prelaunch test samples for the Viking mission.
Interestingly, this was the only terrestrial sample testing by Viking
that did not contain organics detectable by the TV-GC-MS (21) yet did
give a positive result for the LR experiment (22). Subsequent analysis
has shown that this soil contains primarily metamorphosed coal,
kerogen (John R. Cronin, personal communication), and some low levels
of amino acids (23). We also found that TV-GC-MS of this sample, even
at temperatures higher than used by Viking (up to 750°C), yielded no
detectable organics. Other soils from the Antarctic show low total
organic levels that would also be undetectable by the Viking GC-MS.

Table 1. Total organic matter (TOM) present in different Mars
analogs soils and its detection by TV-GC-MS

The arid core regions of the Atacama Desert (Yungay, Chile) contain
Mars-like soils in the surface that have extremely low levels of
culturable bacteria, low organic concentrations (20-40 µg of C per
gram of soil), and the presence of a nonchirally specific oxidant
(14). The level of organics in these soils (see Table 1) would be
undetectable by TV-GC-MS at Viking temperatures but detectable at
higher temperatures (750°C). The organics present in these soils are
dominated by carboxylic acids and polycyclic aromatic hydrocarbons (as
determined in the extracts by the NMR and IR). Soils from the Libyan
and La Joya Deserts also contain very low levels of organics (20-70 µg
of C per gram of soil) that are undetectable by TV-GC-MS. Samples from
the wetter regions of the Atacama, which contain 400-440 µg of C per
gram of soil, are easily detectable by the Viking TV-GC-MS protocol
(see Table 1).

Soil samples from jarosite-containing soils also contain high levels
of organics (140-1,500 µg of C per gram of soil; see Table 1). In
contrast to the desert soils, this organic material was not readily
detectable by using the Viking TV-GC-MS protocol. TV at higher
temperatures (750°C) results in the detection of low levels of benzene
in comparison with samples from Las Juntas, where the levels of
organics are considerable lower. Fig. 1 shows that CO2 is expected to
be the major thermodynamically stable carbon species at 750°C when
organic matter is subjected to thermal treatment in the presence of
ferric sulfate and pyrite (<95%), two minerals present in the Rio
Tinto sediments; if pyrite is the main component (>95%) in the mineral
matrix, then carbon disulfide (CS2) is the major thermodynamically
stable carbon species. TV of the organic material (1,050-1,500 µg of C
per gram of soil) present in the Rio Tinto sediments produces carbon
dioxide as the most important carbon species. Fig. 2 demonstrates that
the oxidation of the organic matter to carbon dioxide is catalyzed by
the iron species present in the inorganic matrix and goes to
completion at temperatures 350°C in the TV chamber. If the organics
from the Rio Tinto sediment are extracted with organic solvents and
then the dry residue is subjected to TV-GC-MS in the absence of
mineral matrix, a variety of organics are detected (see Fig. 3).
Organic molecules larger than seven carbon atoms do not elute from the
chromatographic column. The organics detected in the extracts were
indigenous from the Rio Tinto sediment and not from contamination
during the processing of samples because blanks run in parallel
indicated the lack of organics in the blanks. We find that organic
detectability is reduced by a factor of >1,000 by TV compared with
extraction by organic solvents. The attenuation in detectability
between liquid extraction and TV for the Panoche soils has also been
reported elsewhere (24).

Fig. 1. Thermodynamically stable carbon species equilibrating at
750°C in an iron matrix containing various quantities of oxidized
[ferric sulfate: Fe2(SO4)3] and/or reduced (pyrite, FeS2) species.
Less than 1,000 µg of organic C per gram of soil was initially present
as stearic acid (C18H36O2). These iron species are present in the
sediments of the Rio Tinto with similar levels of organic matter.
Organic compounds are thermodynamically unstable in the presence of
iron, and the carbon species that are thermally stable contained only
one carbon atom at 750°C.

Fig. 2. Percent oxidation of the initial organic carbon to carbon
dioxide catalyzed by the iron species present in the Rio Tinto during
the TV step at various temperatures in an inert atmosphere. The total
organic matter content in the Rio Tinto sediment (RT04-01) was
determined to be 1,200 µg of C per gram of soil by titration of 1 g of
soil with permanganate and subsequent analysis by GC-MS. The degree of
oxidation of the organic matter during the TV step of 20-40 mg of
sediment was derived from the amount of carbon dioxide detected by TV-
GC-MS. Because of the inhomogeneous distribution of the organics in
the sediment and the small amount of sample used for TV-GC-MS, the
degree of oxidation of some samples exceeds 100%.

Fig. 3. Reconstructed ion gas chromatograms of the volatile
fraction released during flash thermal volatilization at 750°C of a 50-
mg sample of RT04-01 before (a) and after (b) removal of the mineral
matrix. Peaks: 1, nitrogen; 2, carbon dioxide; 3, water; 4, methanol;
5, 1-propene; 6, sulfur dioxide; 7, 1,3-butadiene; 8, acetonitrile; 9,
2-propanone; 10, 1-pentene; 11, cyclopentene; 12, benzene; 13,

Another iron-containing soil used as a Mars analog is the NASA Mars-1
martian soil simulant. The main component of this soil is weathered
basalt known as palagonite from a cinder cone south of Mauna Kea,
Hawaii. This volcanic soil has visible and near-IR spectral properties
that are very similar to martian surface materials as determined by
remote sensing (18). In addition, the major inorganic elements in the
soil roughly match the bulk composition of the soils at the Viking
landing sites (18). Because this soil is from Hawaii, it is not
surprising that it contains organic material at 1,200-1,400 µg of C
per gram of soil (Table 1) and microorganisms. Like the jarosite-
containing soils, no organics are detected with the Viking TV-GC-MS
protocol. If the endogenous nonvolatile organics present in the Mars-1
soil simulant are thoroughly removed by organic solvent extraction,
and then the dried soil is doped with stearic acid in different
concentrations, the detectability of this organic material is greatly
reduced when processed by TV due to the catalytic oxidation of the
organics by the iron oxides present in the soil (see Fig. 4).

Fig. 4. Reconstructed ion gas chromatograms of the volatile
fraction released during flash TV. The sample consisted of stearic
acid doped in an organic-free NASA Mars-1 martian soil simulant at
750°C in an inert atmosphere composed of helium: 50 (a), 10 (b), 5
(c), 1 (d), 0.5 (e), and 0.1 (f) mg of C per gram of simulant. Peaks:
1, formic acid; 2, 1-butene; 3, 2-pentene; 4, benzene; 5,
methylbenzene; 6, ethylbenzene; 7, methylethylbenzene. For simplicity,
only the major peaks are labeled in the chromatograms. The NASA Mars-1
martian soil simulant was thoroughly washed with methylene chloride/
methanol (2:1) over 24 h to remove the organics in a Soxhlet
apparatus. The gas chromatograms of this martian soil simulant after
solvent cleaning did not show organics by TV-GC-MS.

The results in Table 1 show two limitations of the Viking TV-GC-MS for
the detection of organic material. First, when organics are present as
low-level refractory substances, the temperatures reached by Viking
(up to 500°C) may be inadequate to release the organics. This
limitation of the Viking instrumentation was recognized but
unavoidable (2), and its implications for detection of organics have
been explored (10, 14). There is a second effect seen in the data in
Table 1 that appears to be due to an interaction of iron in the soil
with the organics during TV. The results of the jarosite and
palagonite soils suggest that during TV there is an oxidation reaction
of the organics catalyzed by the iron in the sample. To investigate
this effect we have constructed a chemical model and an associated set
of experimental simulations to determine the effect of iron compounds
on 1,000 µg of C per gram of soil from stearic acid on a silica matrix
during thermal heating. Fig. 5 shows the results of both the
theoretical model and the experimental simulations. The thermochemical
model predicts that the thermally stable oxidized carbon species at
750°C are CO2 and CO. The lower and upper dotted lines indicate the
predicted conversion to CO2 and the sum of CO2 and CO, respectively.
In the experimental simulations, CO was not detected by TV-GC-MS
possibly because it was readily oxidized to CO2 by the water molecules
absorbed in the mineral matrix from the ambient humidity. However, the
oxidation of stearic acid to CO2 falls within the predicted range,
indicating that the organics are readily oxidized by TV-GC-MS, with
samples containing >0.01% iron in the form of oxides or sulfate salts.
A similar result is obtained at 500°C. If the samples contain higher
levels of stearic acid (1,000 µg of C per gram of soil), then the
oxidation of the organics does not go to completion in the TV step,
and several organic fragments are detected by TV-GC-MS. Therefore, the
degree of attenuation of organic detection by iron compounds in the
soil is not linearly dependent. Consequently TV-GC-MS per se is not an
adequate tool for the study of organics in soils with low levels of
organics and high iron content, as is expected on Mars. If the organic
material is separated from the inorganic matrix by water or organic
solvent extraction and then the dried residue is subjected to TV-GC-
MS, a variety of organic compounds are detected (see Fig. 3).

Fig. 5. Oxidation of a 1,000 µg of C from stearic acid with iron
species present in silica by flash TV at 750°C in an inert atmosphere
composed of helium. Symbols correspond to experimental data, and
dotted lines are predicted. Open circles and triangles are Fe2O3 and
Fe2(SO4)3, respectively. Solid symbols indicate values of oxidation
with sulfuric acid.

Because carbon dioxide was replaced by hydrogen in some Viking TV-GC-
MS experiments, we have investigated whether hydrogen would have
counterbalanced the oxidizing power of the iron species present in the
martian soil. The iron content in the soil of Mars was determined by x-
ray fluorescence spectroscopy, and based on this it was inferred that
Fe2O3 composes 19% of the soil at both Viking landing sites (25). Our
thermodynamic analysis shows that at the Viking temperatures (200-
500°C), the reduction of hematite (Fe2O3) by hydrogen is
thermodynamically favored; however, in the gas phase the dissociation
of molecular hydrogen to atomic hydrogen (a necessary step to cause
the reaction) is extremely slow at temperatures of <1,500°C (26).
Hematite is known to catalyze its own reduction to wüstite (FeO) via
magnetite (Fe3O4) in the presence of hydrogen according to the
following reactions:


This process takes place at temperatures of <1,000°C (27-29), but the
reduction is kinetically controlled by hydrogen pressure (29) and
temperature (27, 28, 30). We have experimentally studied the oxidation
of hydrogen to water by the hematite present in the NASA Mars-1
martian soil simulant in the temperature range from 200°C to 1,200°C.
The hydrogen pressure in the TV chamber was 6.4 atm (1 atm = 101.3
kPa), 13 times higher than that used in the Viking experiments (0.5
atm) (2). Fig. 6a shows the evolution of water vapor from heating the
NASA Mars-1 martian soil simulant in helium and hydrogen atmospheres
by TV-MS. At temperatures between 200°C and 650°C, there is a broad
peak in both experiments that originates from the dehydration of the
mineral phases of the soil simulant. However, at temperatures of

>650°C there is a significant enhancement in the production of water

in the presence of hydrogen, reaching a maximum at 930°C. This water
originates from the oxidation of hydrogen catalyzed by hematite. This
result is consistent with previous studies on the reduction of pure
hematite, where the highest reduction rates occur at temperatures of
910°C (28).

Fig. 6. MS ion current curves for water vapor as a function of
temperature for the NASA Mars-1 martian soil simulant (a) and jarosite
from the Panoche Valley (b). Solid lines show values for experiments
run in a helium atmosphere, and dotted lines show values for
experiments run in a hydrogen atmosphere.

We also studied the oxidation of hydrogen to water by jarosite. Our
thermodynamic analysis shows that, at the Viking temperatures (200-
500°C), the oxidation of hydrogen to water by jarosite is
thermodynamically favored. Fig. 6b shows the evolution of water vapor
from heating jarosite from the Panoche Valley in helium and hydrogen
atmospheres by TV-MS. In both experiments, there are three peaks at
305°C, 405°C, and 790°C that originate by the stepwise dehydration of
jarosite, KFe3(SO4)2(OH)6. Each step involves the loss of two hydroxyl
units, resulting in the formation of an oxide and the evolution of a
water molecule (31). In the presence of hydrogen, there are two
additional water peaks caused by the reduction of jarosite centered at
540°C and 940°C, respectively. The first reduction corresponds to the
decomposition of jarosite into magnetite, iron(II) sulfide, potassium
sulfate, and water vapor, according to the following reaction:

The second reduction is due to reaction of magnetite with hydrogen
according to Eq. 2.

The above experiments clearly demonstrate that shifting from carbon
dioxide to hydrogen atmospheres in the Viking TV-GC-MS did not
overcome the oxidizing power of the Fe2O3 present in the martian soil
at both Viking landing sites. For jarosite-rich soils, such as those
found in the Meridiani Planum site, only a slight neutralization
effect occurs as a result of heating to 500°C in the presence of

Our results influence the interpretation of the Viking TV-GC-MS data.
The fact that no organic molecules were released by this analytical
treatment during the analysis of the Mars soils does not demonstrate
that there were no organic materials on the surface of Mars because it
is feasible that they were too refractory to be released at the
temperatures achieved or were oxidized during the TV step by the iron
present in the soil. The release of 50-700 ppm of CO2 by TV from 200°C
to 500°C in the Viking analysis (2) may indicate that an oxidation of
organic material took placed. The water that evolved in the
volatilization experiments (0.01-1.0%) could be associated with the
oxidation of hydrogen present in the organic matter by the iron oxides
as well as water present in the soil. The detection of CO2 evolving
from the heating of martian samples in the TV-GC-MS experiments
required a major change in the experimental procedure of the
instrument. In all samples analyzed by TV-GC-MS experiments on the
Viking 1 Lander and in two of nine experiments with two samples of the
Viking 2 Lander, the martian soil was heated in a 13CO2 atmosphere.
H2, which was the carrier gas for the gas chromatograph, was not used
to avoid the possible catalytic or thermally induced reduction of
organic material possibly present in the sample (2). However, in an
effort to lower the detection limit for the most volatile components,
H2 was used in two sample experiments (2). The source of the H2 was
the gas chromatograph carrier gas, and the net hydrogen pressure in
the sample oven was 0.5 atm. Our thermodynamic analysis shows that, at
the Viking temperatures (200-500°C), the reduction of iron oxides by
hydrogen is thermodynamically favored; however, our experimental data
indicate that the reaction is kinetically controlled and does not
occur at temperatures of <650°C. Therefore, it seems unlikely that
hydrogen could have neutralized the oxidizing power of the Fe2O3
present in the martian soil. The CO2 released from the thermal
treatment of the martian soil could have also originated from an
inorganic source, such as carbonates (2); however, carbonate minerals
do not seem to be important in the martian environment (32). Thermal
IR spectra of the martian surface indicate the presence of small
concentrations (2-5 wt %) of carbonates, specially dominated by
magnesite, MgCO3 (33). Because magnesite starts to decompose into
magnesium oxide (MgO) and CO2 at 490°C (34) and considering that the
amount of CO2 released in the martian soil did not change from 350°C
to 500°C (2), we can conclude that the effect of magnesite in the
martian soil at Viking Landing Site 2 was negligible. Certainly most
of the CO2 and H2O detected by the Viking TV-GC-MS was derived from
desorption from the soil as suggested (2). We are demonstrating that
some fraction could have been derived from oxidation of organics.
Therefore, the question of whether organic compounds exist on the
surface of the planet Mars was not conclusively answered by the
organic analysis experiment carried out by the Viking Landers.
Furthermore, it is important that future missions to Mars include
other analytical methods to search for extinct and/or extant life in
the martian soil. The Thermal Evolved Gas Analyzer instrument on
NASA’s 2007 Mars Scott Phoenix mission is a TV-MS for the analysis of
water, carbon dioxide, and volatile organics (35). The Sample Analysis
at Mars Instrument Suite for the upcoming NASA 2009 Mars Science
Laboratory mission will include laser desorption MS for analysis of
insoluble refractory organics, solvent extraction followed by chemical
derivatization coupled to GC-MS, and TV-GC-MS for the analysis of
soluble and insoluble organics, respectively. The Mars Organic
Detector for the European Space Agency ExoMars mission scheduled for
launch in 2011 or 2013 will include a TV chamber connected to a cold
finger for the sublimation of amino acids and polycyclic aromatic
hydrocarbons, which will then be analyzed by capillary electrophoresis
using a fluorescence detector (36).

For further detail, see Supporting Materials and Methods, which is
published as supporting information on the PNAS web site. Total
organic matter was determined by titration with the oxidation of
permanganate and by its oxidation to carbon dioxide followed by GC
(model no. HP-5890; Hewlett-Packard, Palo Alto, CA) MS (model no.
HP-5989B; Hewlett-Packard) analysis. Elemental analysis was done with
a model EA1108 analyzer (Fisions, Loughborough, U.K.) at 1,200°C. TV-
GC-MS was performed with a coil filament-type pyrolyzer (Pyroprobe
2000; CDS Analytical, Inc., Oxford, PA) coupled to GC-MS (model nos.
HP-5890 and HP-5989B). Organics from the soil were extracted by a
Soxhlet system with methylene chloride/methanol (2:1) over 8 h, and
the dried residue was analyzed by 1H NMR (Eclipse 300-MHz
spectrometer; JEOL, Ltd., Tokyo, Japan), Fourier transform IR
spectroscopy (Tensor 27 spectrometer; Bruker, Billerica, MA), and by
TV-GC-MS with a ribbon element probe for direct deposition. The carbon
isotope analysis was performed with MS (Delta Plus XL analyzer;
Finnigan, Breman, Germany) equipped with a Flash 1112EA elemental
analyzer. Hydrogen oxidation of soil analogs was carried out by
replacing helium with hydrogen in the oven of the TV-MS analysis.
Thermochemical modeling was carried out with the FactSage software

{To whom correspondence should be addressed. E-mail:}

From the archive, originally posted by: [ spectre ]



12-29-03 By Mark Floyd, 541-737-0788
SOURCE: Martin Fisk, 541-737-5208

CORVALLIS, Ore. – A team of scientists has discovered bacteria in a
hole drilled more than 4,000 feet deep in volcanic rock on the island
of Hawaii near Hilo, in an environment they say could be analogous to
conditions on Mars and other planets.

Bacteria are being discovered in some of Earth’s most inhospitable
places, from miles below the ocean’s surface to deep within Arctic
glaciers. The latest discovery is one of the deepest drill holes in
which scientists have discovered living organisms encased within
volcanic rock, said Martin R. Fisk, a professor in the College of
Oceanic and Atmospheric Sciences at Oregon State University.

Results of the study were published in the December issue of
Geochemistry, Geophysics and Geosystems, a journal published by
the American Geophysical Union and the Geochemical Society.

“We identified the bacteria in a core sample taken at 1,350 meters,”
said Fisk, who is lead author on the article. “We think there could be
bacteria living at the bottom of the hole, some 3,000 meters below the
surface. If microorganisms can live in these kinds of conditions on
Earth, it is conceivable they could exist below the surface on Mars as

The study was funded by NASA, the Jet Propulsion Laboratory, California
Institute of Technology and Oregon State University, and included
researchers from OSU, JPL, the Kinohi Institute in Pasadena, Calif.,
and the University of Southern California in Los Angeles.

The scientists found the bacteria in core samples retrieved during a
study done through the Hawaii Scientific Drilling Program, a major
scientific undertaking run by the Cal Tech, the University of
California-Berkeley and the University of Hawaii, and funded by the
National Science Foundation.

The 3,000-meter hole began in igneous rock from the Mauna Loa volcano,
and eventually encountered lavas from Mauna Kea at 257 meters below the

At one thousand meters, the scientists discovered most of the deposits
were fractured basalt glass – or hyaloclastites – which are formed when
lava flowed down the volcano and spilled into the ocean.

“When we looked at some of these hyaloclastite units, we could see they
had been altered and the changes were consistent with rock that has
been ‘eaten’ by microorganisms,” Fisk said.

Proving it was more difficult. Using ultraviolet fluorescence and
resonance Raman spectroscopy, the scientists found the building blocks
for proteins and DNA present within the basalt. They conducted chemical
mapping exercises that showed phosphorus and carbon were enriched at
the boundary zones between clay and basaltic glass – another sign of
bacterial activity.

They then used electron microscopy that revealed tiny (two- to
three-micrometer) spheres that looked like microbes in those same parts
of the rock that contained the DNA and protein building blocks. There
also was a significant difference in the levels of carbon, phosphorous,
chloride and magnesium compared to unoccupied neighboring regions of

Finally, they removed DNA from a crushed sample of the rock and found
that it had come from novel types of microorganisms. These unusual
organisms are similar to ones collected from below the sea floor, from
deep-sea hydrothermal vents, and from the deepest part of the ocean –
the Mariana Trench.

“When you put all of those things together,” Fisk said, “it is a very
strong indication of the presence of microorganisms. The evidence also
points to microbes that were living deep in the Earth, and not just
dead microbes that have found their way into the rocks.”

The study is important, researchers say, because it provides scientists
with another theory about where life may be found on other planets.
Microorganisms in subsurface environments on our own planet comprise a
significant fraction of the Earth’s biomass, with estimates ranging
from 5 percent to 50 percent, the researchers point out.

Bacteria also grow in some rather inhospitable places.

Five years ago, in a study published in Science, Fisk and OSU
microbiologist Steve Giovannoni described evidence they uncovered of
rock-eating microbes living nearly a mile beneath the ocean floor. The
microbial fossils they found in miles of core samples came from the
Pacific, Atlantic and Indian oceans. Fisk said he became curious about
the possibility of life after looking at swirling tracks and trails
etched into the basalt.

Basalt rocks have all of the elements for life including carbon,
phosphorous and nitrogen, and need only water to complete the formula.

“Under these conditions, microbes could live beneath any rocky planet,”
Fisk said. “It would be conceivable to find life inside of Mars, within
a moon of Jupiter or Saturn, or even on a comet containing ice crystals
that gets warmed up when the comet passes by the sun.”

Water is a key ingredient, so one key to finding life on other planets
is determining how deep the ground is frozen. Dig down deep enough, the
scientists say, and that’s where you may find life.

Such studies are not simple, said Michael Storrie-Lombardi, executive
director of the Kinohi Institute. They require expertise in
oceanography, astrobiology, geochemistry, microbiology, biochemistry
and spectroscopy.

“The interplay between life and its surrounding environment is
amazingly complex,” Storrie-Lombardi said, “and detecting the
signatures of living systems in Dr. Fisk’s study demanded close
cooperation among scientists in multiple disciplines – and resources
from multiple institutions.

“That same cooperation and communication will be vital as we begin to
search for signs of life below the surface of Mars, or on the
satellites of Jupiter and Saturn.”

Martin Fisk
email: mfisk [at] coas [dot] oregonstate [dot] edu

Evidence of biological activity in Hawaiian subsurface basalts


The Hawaii Scientific Drilling Program (HSDP) cored and recovered
igneous rock from the surface to a depth of 3109 m near Hilo, Hawaii.
Much of the deeper parts of the hole is composed of hyaloclastite
(fractured basalt glass that has been cemented in situ with secondary
minerals). Some hyaloclastite units have been altered in a manner
attributed to microorganisms in volcanic rocks. Samples from one such
unit (1336 m to 1404 m below sea level) were examined to test the
hypothesis that the alteration was associated with microorganisms. Deep
ultraviolet native fluorescence and resonance Raman spectroscopy
indicate that nucleic acids and aromatic amino acids are present in
clay inside spherical cavities (vesicles) within basalt glass. Chemical
mapping shows that phosphorus and carbon were enriched at the
boundary between the clay and volcanic glass of the vesicles.
Environmental scanning electron microscopy (ESEM) reveals two to
three micrometer coccoid structures in these same boundaries. ESEM
-linked energy dispersive spectroscopy demonstrated carbon,
phosphorous, chloride, and magnesium in these bodies significantly
differing from unoccupied neighboring regions of basalt. These
observations taken together indicate the presence of microorganisms
at the boundary between primary volcanic glass and secondary clays.
Amino acids and nucleic acids were extracted from bulk samples of
the hyaloclastite unit. Amino acid abundance was low, and if the
amino acids are derived from microorganisms in the rock, then there
are less than 100,000 cells per gram of rock. Most nucleic acid
sequences extracted from the unit were closely related to sequences
of Crenarchaeota collected from the subsurface of the ocean floor.

Received 3 June 2002; accepted 16 October 2003; published 11 December

Astrobiology Magazine (AM): You’ve said that, in our investigations
of the solar system, you hope we find a completely alien life form.
Could you explain what you mean by that?

Chris McKay (CM): I think one of the key goals for astrobiology should
be the search for life on other planets, and in particular the search
for a second genesis. And by that, I mean life that represents an
independent origin from life on Earth. All life on Earth is related;
all can be mapped onto a single web of life.

If there is a form of life that started separately, it might have some
important differences from Earth life. It might still be DNA-based, but
with a different genome than life on Earth. Or it might not be
DNA-based at all.

Think of Earth life as a book written in English. There’s an
alphabet, there’s words, and there’s a language structure. A book
in Spanish has the same alphabet, but it’s clear that it’s a
different language — there are different words with different
constructions. A book in Hebrew, meanwhile, has a different alphabet. A
book in Chinese doesn’t even have an alphabet. It has a completely
different logic, using symbols to represent ideas or words directly.
All four of those books — English, Spanish, Hebrew and Chinese —
could be about the same topic, and therefore contain the same
information. So at an ecological level they would all be the same, but
they have fundamentally different ways of representing that

In our biology, the alphabet is A, T, C, and G — the letters in the
genetic code. The words are the codons that code for that. It could be
that alien life will have the same alphabet but different words, the
way Spanish is different from English. But it could be something
completely different that doesn’t use DNA, like the Chinese book.

AM: So if we did find a completely different basis for life, what would
we learn from the comparison studies? For instance, could it help us
develop a standard definition for life?

CM: It certainly will contribute to understanding life in a more
general sense. But it may not contribute to a definition. In the end,
we may have a complete understanding of life and still no definition.
There are some things that are like that — for example, fire. We have
a complete understanding of fire, and yet it’s very hard to define it
in such a way that distinguishes between a hot charcoal and a raging
flame and something like the sun. Fire is a process, so it has
different aspects.

Carol Cleland and Chris Chyba have said that defining life is like
trying to define water before the development of modern chemistry.
Once we know what it is — H2O — we’ll have a definition for it. But
there are a lot of things that we understand and can duplicate and
simulate, but we still don’t have a definition for. That’s a
limitation of what a definition is — it tries to categorize things in
a simple way. Some things, like a molecule of water, are ultimately
simple. But a process like fire is not a simple thing, and it resists
being categorized in a simple way.

Life may be that way. Even after we’ve discovered many examples of
it, even after we can reproduce it in the lab and can tie it to
fundamental physical and chemical principles, we may not have a simple

AM: If there is alien life out there, how could we hope to detect it
with current exploration methods?

CM: We know how to detect Earth-based life, but to detect alien life we
need a more general test. We could use a property of life that I call
the LEGO Principle. Life is made up of certain blocks that are used
over and over again. Life is not just a random collection of molecules.
For example, life on Earth is made up of 20 L-amino acids which form
the proteins, the five nucleotide bases which form RNA and DNA, some
D-sugars which form the polysaccharides, and some lipids which form the
lipid membranes and fatty molecules. So that kit of molecules — the
LEGO kit of Earth — is used to build biomass.

Life has to pick a set of molecules that it likes to use. A random
distribution of organic molecules is going to have a smooth
distribution, statistically-speaking. For instance, for the amino acids
found in meteorites, there are no systematic differences in the
concentrations of L versus D. Certainly in a Miller-Urey experiment, L-
and D-amino acids are produced equally.

But for organic molecules associated with life on Earth, the
distribution is not smooth. Life uses molecules it likes in very high
concentrations, and it doesn’t use the molecules it doesn’t like.
So you’re much more likely to find the L-amino acids on Earth than
their D counterparts. You’re much less likely to find amino acids
that aren’t in that set of 20 that life uses.

I think that test can be generalized if we find organic material on
Mars or on Jupiter’s moon Europa. We can analyze the distribution of
organic molecules, and if they represent a very unusual distribution,
with concentrations of certain molecules, that would be an indication
of biological origin. If the molecules are different than the molecules
of Earth life, then that would be an indication of an alternative
biological system.

AM: Since all the planets in the solar system formed from the same
basic materials, do you think life elsewhere could have the same
preferences and biases as life on Earth?

CM: Certainly the places we’re looking for life — Mars and Europa
— are going to have carbon-based, water-based life, for the reasons
you just said. That’s what those planets are made out of; that’s
what is in those environments. But whether they’re going to be
exactly the same as Earth life at the next level of complexity is, I
think, debatable. By the next level of complexity, I mean how those
carbon atoms arrange to form the basic building blocks.

Some people have argued that there is only one way to do it — that the
fitness landscape of life has a single peak, and no matter where you
start, life is going to climb that peak to the summit. And life
anywhere is going to end up using the same molecules because they’re
the best, most efficient molecules. There’s one best biochemistry,
and we’re it.

Does life always evolve to reach the same fitness peak, or can there be
multiple peaks that different life forms could strive to reach?

That assumes the fitness landscape is just a single peak, like Mount
Fuji. But maybe the landscape is a mountain range with a bunch of
peaks, and the range is not continuous. If you start in one place,
there are only certain fitness peaks that you could reach, and if you
start somewhere else, there’s no way to get over to those peaks
because there’s a zone in-between that’s not a viable biological

We don’t know what the fitness landscape for life looks like. All we
know is that there’s one peak at least that we’re sitting on, but
we don’t see the topography of the whole system. I would argue that
organic chemistry is sufficiently complicated and diverse to have more
than one single, global maximum.

AM: Do you think it might be related to a planet’s environment? That
there might be a peak for Earth, a peak for Mars, a peak for Europa?
That chemical systems will develop and adapt in an optimum way to their
particular environment?

CM: It could be, but I would guess not. I think that as long as the
environment is defined by liquid water, the differences will be just
chance. The molecules that life happened to put together are what
evolutionists call “frozen accidents.”

Life uses L-amino acids, but why not D-amino acids? We don’t think
there’s any selective pressure of L versus D. It’s a trivial
difference. Perhaps life just had to choose one or the other.

It’s like driving, where everybody has to drive on one side of the
road. It really doesn’t matter if everybody drives on the left, like
England, or on the right, like most of the rest of the world. The fact
that England drives on the left and others drive on the right is just a
frozen accident. It would be very hard to change now, but there’s no
fundamental physical reason why they drive on the left and we drive on
the right. It’s a historical artifact.

My guess is that a lot of biochemistry is just a historical artifact.
Where you start off in this biochemical landscape determines where you
end up, and you end up at the optimum near you. Whereas if you start
off, for some reason, someplace differently, you might end up in a
completely different optimum, with a completely different set of
molecules — all operating in water because that’s the medium that
all these environments that we’re looking at have in common. Because
they have water in common, the range of possible environmental
influences, I think, is small.

AM: But if that were true, then why aren’t there multiple unrelated
forms of life on Earth?

CM: I think the answer is because life is a winner-take-all game.
There’s no mercy. If at one time there were many competing forms of
life on Earth, the others were driven to extinction because life is
competing at a system level for resources — physical space,
sunlight, nutrients, and so on.

As long as different species have different ecological space, they
don’t compete directly. But species that directly compete face an
unstable situation. If there’s a complete overlap on their needs and
requirements, then one will win and one will lose. For an entire system
of life, the requirements are energy, nutrients, and space. Since those
are exactly the same requirements of an alternative system, there’s a
hundred percent competition.

Now, that doesn’t prove that alternate life forms couldn’t be here.
There’s been some speculation that there might be a shadow biosphere
on Earth, and some people are trying to find traces of that. But so
far, they’ve found nothing.

From the archive, originally posted by: [ spectre ]

Extreme seabed-survival boosts hope of aliens

22:00 28 August 2006 news service
Rob Edwards

Microbes discovered by a lake of liquid carbon dioxide under the sea
off Taiwan could help us locate life on Mars, researchers say.

Japanese and German researchers have found billions of bacteria and
other tiny organisms living in a layer of sediment which traps the CO2
under the seabed. Their survival in such a hostile natural environment
suggests that something similar could be happening on other planets.

If water and CO2 are present below the surface in polar environments,
says Fumio Inagaki at the Japan Agency for Marine-Earth Science and
Technology in Yokosuka, “I expect that life signatures utilising
chemical materials and CO2 for growth might be found.”

Inagaki’s team and researchers at the Max Planck Institute for Marine
Microbiology in Bremen, Germany, investigated an area at the southern
end of the Okinawa Trough, about 1400 metres under the East China Sea.
There, hot black sulphurous fluids are vented into the water from two
seabed “chimneys” known as Tiger and Lion, a stunning phenomenon
captured on video by the research team.

Surreal sight

The microbes were discovered 50 m south of the chimneys in samples
taken from the crust of sediment covering a lake of liquid CO2. The
video also shows a clear stream of CO2 bubbles escaping from the hole
made by the researchers’ sample corer.

This is a sight that few people have ever seen, says Kenneth Nealson at
the University of Southern California in Los Angeles, US. It looks
“almost surreal”, he says in a commentary accompanying the research in
the journal Proceedings of the National Academy of Sciences.

Inagaki hopes that his research will also help plans to dispose of
climate-wrecking CO2 by injecting it into the seabed. Care needs to be
taken to make sure that acidification does not damage ecosystems, he
told New Scientist.

Journal reference: Proceedings of the National Academy of Sciences
(DOI: 10.1073/pnas.0606083103)

From the Cover
Microbial community in a sediment-hosted CO2 lake of the southern
Okinawa Trough hydrothermal system

Fumio Inagaki*,,, Marcel M. M. Kuypers, Urumu Tsunogai, Jun-ichiro
Ishibashi¶, Ko-ichi Nakamura||, Tina Treude, Satoru Ohkubo, Miwako
Nakaseama¶, Kaul Gena**, Hitoshi Chiba**, Hisako Hirayama*, Takuro
Nunoura*, Ken Takai*, Bo B. Jørgensen, Koki Horikoshi*, and Antje

*Subground Animalcule Retrieval (SUGAR) Program, Extremobiosphere
Research Center, Japan Agency for Marine-Earth Science and Technology
(JAMSTEC), Yokosuka 237-0061, Japan;  Max Planck Institute for Marine
Microbiology, 28359 Bremen, Germany;  Department of Earth and Planetary
Sciences, Graduate School of Science, Hokkaido University, Sapporo
060-0810, Japan; ¶Department of Earth and Planetary Sciences, Faculty
of Sciences, Kyushu University, Fukuoka 812-8581, Japan; ||Institute of
Geology and Geoinformation, National Institute of Advanced Industrial
Science and Technology (AIST), Tsukuba 305-8567, Japan; and
**Department of Earth Science, Okayama University, Okayama 700-8530,

Communicated by Norman H. Sleep, Stanford University, Stanford, CA,
July 21, 2006 (received for review March 10, 2006)

Increasing levels of CO2 in the atmosphere are expected to cause
climatic change with negative effects on the earth’s ecosystems and
human society. Consequently, a variety of CO2 disposal options are
discussed, including injection into the deep ocean. Because the
dissolution of CO2 in seawater will decrease ambient pH considerably,
negative consequences for deep-water ecosystems have been predicted.
Hence, ecosystems associated with natural CO2 reservoirs in the deep
sea, and the dynamics of gaseous, liquid, and solid CO2 in such
environments, are of great interest to science and society. We report
here a biogeochemical and microbiological characterization of a
microbial community inhabiting deep-sea sediments overlying a natural
CO2 lake at the Yonaguni Knoll IV hydrothermal field, southern Okinawa
Trough. We found high abundances (>109 cm-3) of microbial cells in
sediment pavements above the CO2 lake, decreasing to strikingly low
cell numbers (107 cm-3) at the liquid CO2/CO2-hydrate interface. The
key groups in these sediments were as follows: (i) the anaerobic
methanotrophic archaea ANME-2c and the Eel-2 group of
Deltaproteobacteria and (ii) sulfur-metabolizing chemolithotrophs
within the Gamma- and Epsilonproteobacteria. The detection of
functional genes related to one-carbon assimilation and the presence of
highly 13C-depleted archaeal and bacterial lipid biomarkers suggest
that microorganisms assimilating CO2 and/or CH4 dominate the liquid CO2
and CO2-hydrate-bearing sediments. Clearly, the Yonaguni Knoll is an
exceptional natural laboratory for the study of consequences of CO2
disposal as well as of natural CO2 reservoirs as potential microbial
habitats on early Earth and other celestial bodies.

anaerobic oxidation of methane | chemolithotroph | CO2 disposal | CO2
hydrate | liquid CO2

Author contributions: F.I., B.B.J., K.H., and A.B. designed research;
F.I., M.M.M.K., U.T., J.-i.I., K.-i.N., T.T., S.O., M.N., K.G., H.C.,
H.H., T.N., K.T., and A.B. performed research; F.I., M.M.M.K., U.T.,
J.-i.I., K.-i.N., T.T., S.O., M.N., K.G., H.C., and A.B. analyzed data;
and F.I., M.M.M.K., and A.B. wrote the paper.
Conflict of interest statement: No conflicts declared.

Data deposition: The 16S rRNA, mcrA, and cbbL gene sequences reported
in this paper have been deposited in the DNA Data Bank of
Japan/European Molecular Biology Laboratory/GenBank databases
(accession nos. AB252422-AB252455).

See Commentary on page 13903.

To whom correspondence should be addressed. E-mail:
inagaki [at] jamstec [dot] go [dot] jp