Potential building blocks of life found on Mars

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An Italian-built drill will probe two metres below the surface and hunt for evidence of life, now or in the past. In chemistry, almost all molecules containing both carbon and hydrogen are organic compounds. "It is a valuable food source for them".

In two studies published today (June 7) in the journal Science, researchers from NASA reported the largest amount of organic matter on Mars ever obtained by the Curiosity rover. Here on Earth, we associate methane with life, but it's a mystery what could be causing it on Mars. "We now have really good reasons to look a whole lot harder", he says. Curiosity sampled mudstone in the top 5 centimeters from the Mojave and Confidence Hills localities within Gale Crater. The space agency already has its eyes on the future as the Mars 2020 Rover has been called a "souped-up science machine" that will expand upon Curiosity's findings.

For the previous mud stone samples that had produced the chlorinated molecules, scientists had heated the powdered rock to 200 degrees Celsius.

Potential contaminants were analyzed and accounted for, so the results are the most conclusive yet.

Both the methane gas and soil compounds are organic matter. NASA says that these molecules may have survived because they bonded with sulfur atoms, which made the long, complex molecules much tougher in the same way as introducing sulfur into the rubber used in tires by vulcanization makes the tires durable.

The compounds might have come from a meteorite, or from geological formations akin to coal and black shale on Earth, or some form of life, Eigenbrode said.

Thanks to the extended time period that Curiosity has spent on Mars it has actually been able to detect seasonal variations in how the methane is produced, and where it settles throughout the year.

Dr Eigenbrode said: "The Martian surface is exposed to radiation from space". By exploring Gale Crater it has shown clear evidence that Mars once had liquid water on its surface, and views of the red planet from orbiting spacecraft have charted a desert landscape that appears to have been swept and hewn into shape by powerful flows of water.

Bottom line: NASA's Curiosity rover has found evidence preserved in Martian rocks, suggesting the planet could have supported ancient life.

The new study reveals the discovery of complex and diverse organic compounds in more detail, however.

The methane study, spearheaded by JPL atmospheric scientist Chris Webster, is also intriguing for astrobiologists. The 2020 Mars rover, whose body is based heavily on that of Curiosity, will also collect and cache samples for eventual return to Earth, where scientists could scrutinize them for any evidence of native Martians. On Mars, that's been a maddening challenge: While scientists have detected bursts of methane on the planet, they've appeared at random - and thus, it's been hard to figure out what the source is.

The most exciting news is that the changes definitely match the Martian seasons, hitting a peak at the end of summer in the northern hemisphere. Sure, if a Martian strolled by a rover's cameras scientists would see it, but the rover is not equipped to make an unambiguous detection of life.

"That's a huge change, completely unexpected", Webster said at the briefing. What do we stand to gain from these missions anyway? "[But] it could also be rock chemistry". "We can not distinguish that". The findings could help to guide the search for ancient microbial life and improve our understanding of seasonal processes on Mars. But chemical reactions that don't involve life can also produce them.