Nasa’s Curiosity rover has detected the clearest evidence yet for the presence of the building blocks of life on Mars. According to the report in the journal Science, the rover found complex organic matter buried beneath the sediments of a lake bed that formed on Mars 3 billion years ago. The development was described in a report from The Guardian on Thursday.
Researchers do not yet understand how the carbon-based compounds were formed. They may be leftover from actual life that once lived on Mars. But it’s also possible they are the result of chemical reactions between rocks, or that they traveled to Mars via comets or other debris from space. The tests researchers have performed so far would not be able to differentiate between these possible origins.
The material was found in mudstone that was drilled from the lakebed. When the material was heated to between 500 and 820 degrees Celsius, the rover detected “aromatic, aliphatic and thiophenic vapours,” that researchers believe were byproducts of larger organic molecules, similar to the organic matter found in coal.
In any case, the findings do show that if organic lifeforms ever existed on Mars, sustenance would have been available.
According to Jennifer Eigenbrode, a biogeochemist at Nasa’s Goddard Space Flight center:
“We know that on Earth microorganisms eat all sorts of organics. It’s a valuable food source for them…while we don’t know the source of the material, the amazing consistency of the results makes me think we have a slam-dunk signal for organics on Mars. 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.”
It’s not the first time Nasa has detected evidence that points toward the presence of organic matter on Mars. In 2015, the Curiosity rover detected organic material that contained chlorine in rocks on the planet. However, questions over whether there was contamination from the rover, or glitches with its instruments cast doubt not the findings. The new discovery is considered much more convincing, and finding organic matter so close to surface suggests even more could be waiting further below the surface.
“If we can find things like fatty acids, that would be the first potential hints of life,” according to Eigenbrode.
The rover has spent 6 years on Mars, carefully traveling a total of 12 miles in the Gale crater.