"There is also possibility that some of that glacial ice may still be there."
Washington, May 28 - In a major breakthrough, geologists have discovered a giant volcano - once covered in glacial ice and nearly twice as tall as Mount Everest - on Mars that may have harboured life.
One of the largest mountains in the solar system, Arsia Mons is the third tallest volcano on Mars and may be home to one of the most recent habitable environments yet found on the Red Planet.
If signs of past life are ever found at older sites, then Arsia Mons would be the next place I would want to go, Kat Scanlon, a graduate student at Rhode Island-based Brown University said.
Using data from NASA's Mars Reconnaissance Orbiter, Scanlon found pillow lava formations, similar to those that form on earth when lava erupts at the bottom of an ocean.
She also found the kinds of ridges and mounds that form on earth when a lava flow is constrained by glacial ice.
This new analysis of the landforms surrounding Arsia Mons shows that eruptions along the volcano's northwest flank happened at the same time that a glacier covered the region around 210 million years ago.
The heat from those eruptions would have melted massive amounts of ice to form englacial lakes - bodies of water that form within glaciers like liquid bubbles in a half-frozen ice cube.
The ice-covered lakes of Arsia Mons would have held hundreds of cubic kilometres of meltwater, Scanlon noted.
Even in the frigid conditions of Mars, that much ice-covered water would have remained liquid for a substantial period of time.
That may have been long enough for the lakes to be colonised by microbial life forms, if in fact such creatures ever inhabited Mars.
In light of this research, it seems possible that those same kinds of environments existed on Mars at this site in the relatively recent past.
There is also possibility that some of that glacial ice may still be there.
The fact that the Arsia Mons site is relatively young makes it an interesting target for possible future exploration, scientists noted in a paper published in the journal Icarus.