Published: Fri, June 08, 2018
Sci-tech | By Lila Blake

Much Ado About Martian Organics

Much Ado About Martian Organics

In 2020, NASA plans to launch a rover that will seek out organics and search for chemical signatures of life in ancient Red Planet rocks.

The "building blocks" for life have been discovered in 3-billion-year-old organic matter on Mars, NASA scientists announced Thursday.

"Curiosity has shown that Gale crater was habitable around 3.5 billion years ago, with conditions comparable to those on the early Earth, where life evolved around that time", she wrote. That leaves open the possibility that microorganisms once populated our planetary neighbour and still might. When the samples reached 500 to 820 degrees Celsius, Curiosity's instruments detected a range of vapours that researchers believe are products of larger organic molecules similar to those found in coal, which were trapped in Martian rocks in the distant past.

So now they want people to think that finding a few organic molecules on Mars is an advance toward finding evidence of past life?

The rover is climbing Mount Sharp, a mountain in the centre of a region known as Gale Crater.

Detecting this organic molecule in the atmosphere, combined with the finding of organic compounds in the soil, has strong implications about potential life on Mars in its past.

Neither paper can say whether past life ever existed on Mars, the scientists said.

There's also excitement because Curiosity found this stuff without having to look very hard: the organics turned up in some mud that looked likely.

A reminder: Organic molecules aren't necessarily produced by organisms; they're just chemical compounds that contain carbon.

The search for life outside Earth focuses on the building blocks of life as we know it, which includes organic compounds and molecules - although these can exist without life. The organic molecules and volatiles, comparable to samples of sedimentary rock rich in organics on Earth, included thiopene, methylthiophenes methanethiol and dimethylsulfide.

Regardless, the detection is a technical achievement, said Williford, because it demonstrates that organic molecules can persist near Mars's surface for billions of years. 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. Much as a detective figures out whodunnit by filling in all the details of a crime first, astrobiologists set about piecing together a picture of the Martian environment to figure out if the planet could even support life, now or in the past. No one knows what's making this methane, but scientists speculate that it's released from underground pockets.

NASA actually isn't looking for life on Mars right now. Curiosity sampled mudstone in the top 5 centimeters from the Mojave and Confidence Hills localities within Gale Crater.

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. Despite its aspirations, the Viking program never even found signs life on Mars. "The first one would be life, which we don't know about".

In the meantime Curiosity has undertaken what Webster calls "the most important measurements of Mars methane made to date".

On Mars, organic molecules could have been produced by some form of either present or past lifeforms.

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