Far beneath the frigid surface of the South Pole of Mars is probably the last place where you might expect the first large body of Martian liquid water would be found. It’s -170 F on the surface, there are no known geothermal sources that could warm the subterranean ice to make a meltwater lake, and the liquid water is calculated to be more than a mile below the surface.
Yet signs of that liquid water are what a team of Italian scientists detected — a finding that they say strongly suggests that there are other underground lakes and streams below the surface of Mars. In a Science journal article released today, the scientists described the subterranean lake they found as being about 20 kilometers in diameter.
The detection adds significantly to the long-studied and long-debated question of how much surface water was once on Mars, a subject that has major implications for the question of whether life ever existed on the planet.
Finding the subterranean lake points to not only a wetter early Mars, said co-author Enrico Flamini of the Italian space agency, but also to a Mars that had a water cycle that collected and delivered the liquid water. That would mean the presence of clouds, rain, evaporation, rivers, lakes and water to seep through surface cracks and pool underground.
Scientists have found many fossil waterways on Mars, minerals that can only be formed in the presence of water, and what might be the site of an ancient ocean.
But in terms of liquid water now on the planet, the record is thin. Drops of water collected on the leg of NASA’s Phoenix Lander after it touched down in 2008, and what some have described as briny water appears to be flowing down some steep slopes in summertime. Called recurrent slope lineae or RSLs, they appear at numerous locations when the temperatures rise and disappear when they drop.
This lake is different, however, and its detection is a major step forward in understanding the history of Mars.… Read more