ITV News — July 25, 2018
A huge 12-mile wide lake of liquid water lies beneath the southern ice cap of Mars, scientists have learned.
Dissolved salts are thought to keep the water fluid, despite having a temperature below freezing point.
The discovery, which has major implications for the chances of life surviving on the Red Planet, was made by an orbiting European probe using ground-penetrating radar.
It is the first time a large stable body of liquid water has been confirmed to exist on Mars.
The lake, similar to those beneath the Antarctic and Greenland ice sheets on Earth, lies about 1.5 kilometres (0.9 miles) below the surface of a region called Planum Australe, close to the Martian south pole, and stretches out for 20 kilometres.
With surface temperatures as low as minus 68C, it would not exist as a liquid under normal conditions.
But dissolved salts of magnesium, calcium, and sodium – known to be present in Martian rocks – are thought to maintain the briny miniature sea by reducing the melting point of water to minus 74C.
An Italian team of scientists detected the lake while carrying out a radar survey using the Mars Express spacecraft.
Between 2012 and December 2015 the Planum Australe region was mapped by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (Marsis) instrument carried on the orbiter.
Radio waves beamed down to the surface by Marsis penetrated through the ice and bounced back to the spacecraft.
Far beneath the ice cap at Mars’s south pole lies a lake of liquid water—the first to be found on the Red Planet: https://t.co/VBue3BcEgn
— News from Science (@NewsfromScience) July 25, 2018