A large underground lake near the South Pole of Mars is the announcement made by an Italian team in the journal Science of July 25, 2018. This discovery was made using Marsis radar installed on the European probe Mars Express. Does this open a new page in the history of the search for life on Mars?
The radar of the European Mars Express spacecraft, in orbit around the red planet since 2003, has detected a large lake under the South Martian pole.
It has been known for a long time that there were oceans on the surface of Mars in the distant past, that there is now ice, and we have even discovered signs of presence of small amounts of liquid water . But this is the first time that we have detected a large mass of water on Mars.
In a study published in the journal “Science”, a team led by Roberto Orosei, of the Institute of Astrophysics of Bologna (Italy) analyzes the radar data of Mars Express and describes a subglacial lake located in the region of Planum Austral, in the Arctic Circle.
This lake, some twenty kilometers long, is 1.5 km below the surface, and can be compared to lakes that have been discovered on Earth under the ice caps of Antarctica or Greenland.
On Mars, however, the temperature is much lower. It is estimated that the water of this lake should be around – 68 degrees. Yet it is liquid water and not ice. The explanation lies in the fact that this water must contain large amounts of magnesium, calcium and sodium salts. This salinity allows the water to remain liquid up to – 74 ° under the pressure conditions encountered under the Martian surface.