New Study Claims Mars Could Have Supported Underground Life

Tuesday, 25 September 2018 - 12:07PM
Mars
Astrobiology
Tuesday, 25 September 2018 - 12:07PM
New Study Claims Mars Could Have Supported Underground Life
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Image credit: Pixabay
At this point, the "will they/won't they" relationship between Mars and some hypothetical form of microbial life has surpassed most soap operas in terms of dramatic reveals. Initial assessments of Mars said it was too cold and too irradiated to support life, but then scientists discovered evidence that microbes could have survived that radiation for millions of years. 

Then the Curiosity rover finds organic molecules inside a rock, but skeptics argue that just because you have the building blocks of life doesn't mean it actually existed. Then a study claims that even if Mars was mostly icy and cold for most of its history, volcanic eruptions could have created warm oases for microbial life to develop. Now there's a new twist: even if the surface was too hostile to life, Mars apparently had enough chemical energy embedded in its crust to support a thriving underground ecosystem for microbes.

The new study is centered on subsurface lithotrophic microbial ecosystems, or "SliMEs," which are made up of tiny organisms that don't rely on sunlight for their energy or food. Instead, these microbes survive by separating electrons from surrounding molecules: especially water molecules, which contain hydrogen. According to Jesse Tarnas, the lead author of the new research (which was published in Earth and Planetary Science Letters): "We showed, based on basic physics and chemistry calculations, that the ancient Martian subsurface likely had enough dissolved hydrogen to power a global subsurface biosphere. Conditions in this habitable zone would have been similar to places on Earth where underground life exists."

The only problem? That was most likely 4 billion years ago.

This new research reinforces the idea that any life Mars once possessed is long gone—even the Mars 2020 rover is aiming to find evidence "past life." Still, exploring Mars' underground may offer the best chance at finding what remains of Martian critters, if they ever existed in the first place.

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