NASA reveals new discoveries suggesting there was once life on Mars

Doug Carpenter
June 8, 2018

The discovery leaves open the possibility that microorganisms once populated the red planet - and still might.

That said, the agency hopes future missions to the red planet, NASA's Mars 2020 rover and ESA's ExoMars rover, could delve into these findings and reveal the complete history of our neighboring planet. About 95 percent of the methane in Earth's atmosphere is produced from biological activity, though the scientists said it is too soon to know if the Martian methane also is related to life.

In a second, potentially more significant finding announced Thursday, scientists reported detection of a seasonal variation in methane levels in the martian atmosphere. Previous research had seen evidence for sporadic methane plumes on Mars, but never seasonally recurring events. The problem was that these organic molecules contained an unusual atom: chlorine. Also pleasing is that the presence of chlorine and sulphur, which both preserve organics, suggests the presence of many more deposits from which to learn more about Mars' past and possible ecosystems. "Organic matter" in this context doesn't mean anything we'd recognize from our lives on Earth. "It tells us that this ancient environment on Mars could have supported life", Eigenbrode said.

The sediments, analysed by the SAM instrument on Curiosity, come from just below the surface, where they have been shielded from most of the UV radiation that would break down organic molecules exposed on the surface.

Now, with years of Curiosity's atmospheric readings at their disposal, Webster and his colleagues were able to analyze 55 Earth months (or roughly three Martian years) of data, finding that there were indeed low levels of background radiation - and that it seemed to experience seasonal surges, almost tripling at its peak near summer's end in the northern hemisphere (and winter's end in the south). "Curiosity has shown that Gale crater (where the material was discovered) was habitable around 3.5 billion years ago, with conditions comparable to those on the early Earth, where life evolved around that time. We can find organic matter preserved in mudstones that are more than three billion years old", Siebach said.

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

According to a report by Science Alert, NASA rover Curiosity's drill bit provided samples of the soil, from two different parts of the Gale crater, offering deeper insights into the organic chemistry of the 300-million-year-old planet.

Curiosity's methane measurements occurred over four-and-a-half Earth years, covering parts of three Martian years.

And the seasonal methane pulse is perhaps, maybe, possibly - but far, far from certainly - the sort of signal Curiosity might detect if life did form back then and was still around somewhere, ten Kate said. Gases released from the samples at temperatures over 500 degrees Celsius were carried by the helium flow directly into a mass spectrometer.

"Are there signs of life on Mars?" Instead, SAM detected fragments of much larger molecules that had been broken up during the high-temperature heating experiment.

In December 2012, the rover's two-year mission was extended indefinitely.

"We have greatly expanded our search for organic compounds, which is fundamental in the search for life", said Paul Mahaffy, study author and director of the Solar System Exploration Division at NASA's Goddard Space Flight Center.

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