The red Martian surface may be barren and arid, but about a mile underneath Mars’ south pole, scientists think they’ve found something remarkable.
Using a ground-penetrating radar aboard the European Space Agency’s (ESA) Mars Express orbiter, a team of researchers appear to have identified a 12-mile (20 kilometer) wide salty lake underneath a massive glacier on Mars.
Their research, published Wednesday in the journal Science, opens up the potential for human water supplies in similar Martian reservoirs, and even the possibility that microbial life may live in this liquid place on Mars.
“We’re very excited about the observation,” Jim Green, NASA’s Chief Scientist who had no involvement in the study, said in an interview.
“Their radar instruments indicate that out of all the things it could be, water is the most likely.”
While Green notes that scientists have spotted water on Mars before, those previous discoveries mostly centered around ephemeral surface water that might appear and disappear on very short time scales.
This new finding, led by ESA scientists, however, is different.
While some 12 miles in diameter, the researchers speculate the underground lake is at minimum 1 meter (over 3 feet) thick, meaning that it’s a long, if thin, underground lake.
“We’ve never found a reservoir of this size that’s like an aquifer [underground water layer] here on Earth,” said Green, noting that Mars was once likely a blue planet like Earth, covered in vast oceans.
This has obvious implications for human exploration of the red planet. It’s already well-known that Mars has thick sheets of ice underneath its north polar regions.
But now, Mars might also have a system of liquid reservoirs near the surface, which could be of great value to astronauts — or anyone trying to settle in for a life on the red planet.
Sure, this extraterrestrial water might be full of salts, but it can be filtered and made pure.
“We can handle that,” said Green.
What’s more, there also might be primitive, microbial life flourishing in these isolated waters, buried deep underground, hidden away from space radiation and Martian surface extremes.
Many astrobiologists — scientists who study life in the universe — usually aren’t too enthused about yet another water discovery on Mars, Rebecca Mickol, an astrobiologist at the Naval Research Laboratory’s Center for Biomolecular Science and Engineering, said in an interview.
“But,” said Mickol, “If there’s a place that can sustain life — that’s another story.”
Life in the Martian underworld?
While this research does provide good evidence that the lake exists, there’s still no definitive proof that such a large body of water really does live under Mars’ surface.
NASA hopes to improve upon this evidence with geologic observations from its InSight Lander, set to land in November.
But if there is indeed a briny pool of frigid water sitting beneath a Martian glacier, life very well could have once survived there over the last 3 billion years.
Or, it could still thrive today.
“Because the surface of Mars is so hostile, I wouldn’t be surprised if organisms lived deep down in the subsurface, especially if there’s a source of water nearby,” said Mickol, noting that microbial life is abundant deep in the Earth.
There are plenty of challenges, however, for anything making its home in this water.