A Glacial, Habitable Environment Discovered on a Martian Volcano: Life on Mars?

Could Mars have hosted life in the past? Scientists think it's certainly a possibility, and a recent discovery certainly hints that this could be the case. Researchers have found that the Martian volcano Arsia Mons may have been home to one of the most recent habitable environments yet found on the Red Planet.

Arsia Mons is nearly twice as tall as Mount Everest, and is the third tallest volcano on Mars. One of the largest mountains in the solar system, it was once volcanically active. Now, scientists have found that during the same time it erupted, around 210 million years ago, there was also a glacier in the region. The heat from the volcanic eruptions would have melted massive amounts of ice in order to form englacial lakes, which are bodies of water that form within glaciers like liquid bubbles in a half-frozen cube. In fact, these lakes would have held hundreds of cubic kilometers of meltwater.

"This is interesting because it's a way to get a lot of liquid water very recently on Mars," said Kat Scanlon, one of the researchers, in a news release. "If signs of past life are ever found at those older sites, then Arsia Mons would be the next place I would want to go."

In fact, Arsia Mons is much younger than the habitable environments spotted by the Curiosity rover and other Mars rovers. The other sites are older than 2.5 billion years, whereas Arsia Mons is a mere 210 million years old.

Could life actually exist within these englacial lakes, though? Even in the frigid conditions of Mars, the ice-covered water would have remained liquid for a substantial period of time-either hundreds or even a few thousand years. That might have been long enough for the water to be colonized with microbial life forms.

"There's been a lot of work on Earth-though not as much as we would like-on the types of microbes that live in these englacial lakes," said Scanlon in a news release. "they've been studied mainly as an analog to [Saturn's moon] Europa, where you've got an entire planet that's an ice covered lake."

Yet this glacial ice may not just be a thing of the past. It's also possible that remnants may still be present.

"Remnant craters and ridges strongly suggest that some of the glacial ice remains buried below rock and soil debris," said James Head, one of the researchers, in a news release. "That's interesting from a scientific point of view because it likely preserves in tiny bubbles a record of the atmosphere of Mars hundreds of millions of years ago. But an existing ice deposit might also be an exploitable water source for future human exploration."

The findings are published in the journal Icarus.