Space Swoon: Liquid water on Mars found in underground aquifer according to scientists

Oh fuck. Is this it? Have scientists really found liquid water on Mars? Well, they certainly fucking think so.

Gizmodo:

After decades of debate, scientists have spotted hints of liquid water trapped beneath the planet’s south polar ice cap.

A team of Italian researchers analyzed radar data taken between May 2012 and December 2015 with an instrument on board the European Space Agency’s Mars Express spacecraft, according to a new paper. Parts of the ice returned strange signals in the instrument.

“We interpret this feature as a stable body of liquid water on Mars,” the authors write in the paper published today in the journal Science.

At this point, there’s lots of evidence that Mars used to have liquid water, based on its topography and other clues. And obviously the planet has frozen water, as evidenced by its ice caps. But whether there’s liquid water currently, either in the dirt or hidden beneath its poles, has long been a matter of discussion and debate.
Artist impression of the Mars Express spacecraft using its radar and finding a bright spot
Graphic: ESA, INAF, Davide Coero Borga

From May 29, 2012 to December 27, 2015, the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on board the Mars Express spacecraft took data on a 200-kilometer-wide (124-mile) area near the planet’s south pole. It shot radio waves at the ground, then recorded how the waves that bounced back had changed. There was nothing strange about the area itself. But a 20-kilometer-wide (12-mile) region beneath the surface seemed to reflect way more of the radar signal than its surroundings.

The bright reflection implied that the region had a much higher value of its dielectric permittivity, an important electrical property for studying penetrating radar. The researchers weighed the options: Could carbon dioxide ice have caused the signal, or some other material? Their analysis suggested that, no, the most likely explanation would be water, which has a much higher dielectric permittivity than ice. That water would have lots of dissolved salts, either as a brine pool or a sludge where water saturated soil, according to the paper.

Why doesn’t the water freeze? First, there’s the dynamics of ice sheets, which can experience sub-surface melting due to the specific pressure and temperature environment (as they do on Earth). Then there’s the dissolved salts. You might remember the phrase “perchlorates” from past Mars water studies—these are molecules that contain chlorine atoms linked to four oxygen atoms. The presence of perchlorate salts can greatly reduce the melting point of water.