Published: Fri, June 08, 2018
Science | By Celia Watts

Newest NASA Discoveries Could Boost Search For Ancient Life On Mars

Newest NASA Discoveries Could Boost Search For Ancient Life On Mars

A NASA robot has found more building blocks for life on Mars, the most complex organic matter yet from 3.5 billion-year-old rocks on the surface of the red planet, the U.S. space agency said on Thursday.

Organic molecules were found in 3 billion-year-old sedimentary rocks near the surface. The European Space Agency plans to launch its own rover in a few years and NASA is building a powerful follow-on to Curiosity, the Mars 2020 rover, that will be equipped with even more powerful instruments to advance the search for life.

"The detection of organic molecules and methane on Mars has far-ranging implications in light of potential past life on Mars", said Inge Loes ten Kate, a Utrecht University scientist in an accompanying article in Science.

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

"Although the surface of Mars is inhospitable today, there is clear evidence that in the distant past, the Martian climate allowed liquid water - an essential ingredient for life as we know it - to pool at the surface", NASA reports.

The discoveries, reported today in two papers in the journal Science, while not evidence of life, provide more tantalising clues about what's happening on Mars, for future missions to investigate. The methane signal has been observed for almost 3 Martian years (nearly 6 Earth years), peaking each summer.

There is a silver lining: as we mention above and NASA was quick to point out, "while commonly associated with life, organic molecules also can be created by non-biological processes and are not necessarily indicators of life", which is encouraging.

But life-hunting Mars missions are coming, and soon. The Martian surface is bombarded with radiation that can degrade organic compounds, explains Eigenbrode. This mudstone gradually formed billions of years ago from silt that accumulated at the bottom of the ancient lake. NASA's six-wheeled Curiosity rover drilled into the planet in late 2014 and early 2015. Now, samples taken from two different drill sites on an ancient lakebed have yielded complex organic macromolecules that look strikingly similar to kerogen, the goopy fossilized building blocks of oil and gas on Earth. What the authors have found is a systematic variation in methane concentration with season, with the highest concentrations occurring at the Gale Crater towards the end of the northern summer.

On top of that, after keeping close tabs on methane levels in the Martian atmosphere, scientists have finally confirmed something weird is definitely going on, and they think they know what's causing it. "It is not telling us that life was there, but it is saying that everything organisms really needed to live in that kind of environment, all of that was there". They therefore suggest that methane could be trapped at depth, gradually seeping to the surface. Despite its aspirations, the Viking program never even found signs life on Mars.

"We don't know, but these results tell us we are on the right track"'.

"With this new data, we again can not rule out microbial activity as a potential source", Webster said. "And it makes us more confident that if biomarkers" - or direct evidence of biologic activity - "are there, we might find them".

"We have no proof that the methane is formed biologically, but we can not rule it out, even with this new data set", Webster said.

Like this: