The Martian subsurface might be a good place to look for possible present-day life on the Red Planet, according to a study.
The study, published in the journal Astrobiology, looked at the chemical composition of Martian meteorites — rocks blasted off of the surface of Mars that eventually landed on Earth.
The analysis determined that those rocks, if in consistent contact with water, would produce the chemical energy needed to support microbial communities similar to those that survive in the unlit depths of the Earth. Because these meteorites may be representative of vast swaths of the Martian crust, the findings suggest that much of the Mars subsurface could be habitable.
“The big implication here for subsurface exploration science is that wherever you have groundwater on Mars, there’s a good chance that you have enough chemical energy to support subsurface microbial life,” said Jesse Tarnas, a postdoctoral researcher at NASA’s Jet Propulsion Laboratory.
“We don’t know whether life ever got started beneath the surface of Mars, but if it did, we think there would be ample energy there to sustain it right up to today,” Tarnas added.
For the study, the researchers wanted to see if the ingredients for radiolysis-driven habitats could exist on Mars. They drew on data from NASA’s Curiosity rover and other orbiting spacecraft, as well as compositional data from a suite of Martian meteorites, which are representative of different parts of the planet’s crust.
The study found that in several different types of Martian meteorites, all the ingredients are present in adequate abundances to support Earth-like habitats.
Unlike Earth, Mars lacks a plate tectonics system that constantly recycle crustal rocks. So these ancient terrains remain largely undisturbed, the researchers noted.
“The subsurface is one of the frontiers in Mars exploration,” said Jack Mustard, Professor at Brown University.
“We’ve investigated the atmosphere, mapped the surface with different wavelengths of light and landed on the surface in half-a-dozen places, and that work continues to tell us so much about the planet’s past. But if we want to think about the possibility of present-day life, the subsurface is absolutely going to be where the action is,” Mustard said.