Temporary lakes once filled and filled on the surface of Mars

Today, water on Mars is trapped in ice deposits or in deep underground lakes. But the water had once sunk to the surface of the planet and researchers found new evidence of its presence on the red planet.

A new study reveals that the Hellas impact basin on Mars once contained a number of ephemeral or generally dry lakes, but filling with water for brief periods.

Aquatic world

Researchers at the SETI Institute, located in the southern hemisphere of the Red Planet, have discovered many of these temporary lakes throughout the history of Mars. The depressions were filled with water from a variety of sources, including groundwater, snowfall, rivers and streams.

Known as paleolakes, these ancient Martian lakes were active when the climate of Mars was radically different from today's. The researchers found that one of the paleolakes is almost completely filled with smooth sediment, which is similar to what scientists have observed in salty lakes of the Andes. This similarity suggests that the conditions on Mars, during the formation of this paleolake, could have resembled those of the Andean mountains – cold and arid.

Paleolakes were found along the water drainage systems, which resulted in smaller surface depressions, or 'lakes', at the edge of Hellas Planitia, a plain in the basin. impact. The lakes were not all the same either. Some may have served as a source for canal systems hundreds of kilometers long, while others may have been crossed by rivers. Still others carry the traces of probable flash floods.

"In the highest resolution images, we could see sediments, deposits and what appeared to be shorelines in some cases in those craters and depressions in which the channels were heading," said Virginia C. Gulick, Senior researcher and researcher at SETI, in an email.