THE WATERS OF MARS
A lake could be a likely location for life on Mars, but anything there needs to have a taste for salt and dark places
Has water finally been found on Mars? In July, ESA announced that radar data taken by Mars Express showed evidence of a lake deep beneath the surface.
“We detected very strong echoes coming from 1.5km below the surface of the south polar cap,” says Roberto Orosei, principal investigator of Mars Express’s radar instrument, MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding). “They point to the presence of liquid water, the natural material that best reflects radar waves.”
As past ‘discoveries’ of Martian water have turned out to be unfounded, the team checked for other possibilities. After several months, they are convinced their theory remains the best explanation. “It’s a body of water 20km across,” says Orosei. “We know that the liquid water must be about 1m thick, or else the radar would not be able to see it.”
Some have wondered whether the lake could harbour Martian life, but any microbes calling the pond home would need to be extremely hardy. To avoid freezing, the water must be so salty no life as we know it could survive there. But as we would currently struggle to drill through 1.5km of ice on Earth, let alone on another planet, it will probably be some time until we can check what the water’s like on Mars.
Radar data from Mars Express’s MARSIS equipment may have found a subsurface lake on Mars under its south pole. Corroborating evidence came in the form of an ExoMars image from May 2018 (bottom) that also revealed layered deposits at the south pole of Mars