Magazine article The Futurist

A Chemical Mission to Mars: Methane Lures Astrobiologists to Look below the Martian Surface

Magazine article The Futurist

A Chemical Mission to Mars: Methane Lures Astrobiologists to Look below the Martian Surface

Article excerpt

For millennia, humans have suspected that life exists on other planets. Science writer Marc Kaufman thinks that it does--and that we might have to look no further than Mars.

"There is a very good chance that [a near-future Mars mission] will say definitively, 'Here are organic compounds,'" says p Kaufman, a Washington Post science reporter and the author of First Contact (Simon & Schuster, 2011).

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Astronomers believe that, billions of years ago, Mars was warm, had liquid water, and could have supported life. Mars cooled over time, and its surface water disappeared, Kaufman explains. But there could be much more ice below the surface, and maybe some remaining microbes.

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"Potentially there was life on Mars three or four billion years ago, when it was wetter and warmer. And as conditions changed, it might have migrated underground," he says.

Kaufman cites Michael Mumma, a NASA astronomer who in 2009 discovered frequent methane emissions from several surface sites across Mars. This could indicate life, says Kaufman, because on Earth, more than 90% of methane comes from living organisms; the rest is produced by volcanoes and other geological phenomena.

Mumma told THE FUTURIST that, in the two years since his methane discovery, he and his research team gathered data on Mars's atmosphere from 24 Earth-based observatories. NASA will publish the findings in late summer 2011. Mumma is hopeful that the information will help scientists judge whether Mars's methane implies Martian life--or just Martian geological activity.

"We're following up on the methane production to identify if the release repeats annually, but also to measure gases that might be key tests of biology versus volcanism," says Mumma.

More insights may emerge from ExoMars, a pair of robotic missions that NASA and the European Space Agency (ESA) will co-launch to examine methane and other trace gases on Mars. According to Mumma, ExoMars may find important chemical clues. For example, if it is accompanied by sulfur dioxide, the methane is probably geological in origin; if hydrogen sulfide ac- companies it, then the methane almost certainly came from something living.

"We are hopeful that, if we see a methane hotspot, we will look closely for these other gases to see what's really happening," says Mumma.

While finding life would be momentous, according to ESA ExoMars Project scientist Jorge Vago, so would finding signs of geological movement. Geological activity would suggest a warm inner core. This means that Mars might have enough heat in zones below its surface to sustain microbial life.

"In either case, it will mean the planet is not dead--either from a geological point of view or from a biological point of view," says Vago.

The first ExoMars mission will launch in 2016 and, upon arriving in Martian aerospace in mid-2017, will deploy a rover that will land on the surface and spend four days analyzing the soil and air. The spacecraft above will continue orbiting and analyzing atmospheric gases for the next two years.

A follow-up ExoMars mission in 2018 will carry a rover with a drilling arm that will tunnel two meters into the soil to obtain dirt and rock samples. Vago says that this drilling will be the deepest that humans have ever before pried into the planet.

"This is a 3-D rover," says Vago. "For the first time, we will be able to look into Mars's third dimension, that of depth."

The rover will deposit the samples into a cache. Sometime after 2024, a third robotic mission may retrieve the samples and fly them back to Earth for astronomers to study in person.

"This mission in 2018, you can think of it as the first element of Mars sample return," says Vago. "The long-term aim is Mars sample return."

Viewing Mars's inner core will probably not be possible any time in the near future, Mumma concludes, but he considers studying the gas emissions up close to be the next-best thing. …

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