Buried lakes of liquid water discovered on Mars - BBC News

Liquid water is vital for biology, so the finding will be of interest to researchers studying the potential for life elsewhere in the Solar System.

Billions of years ago, water flowed in rivers and pooled in lakes on the Martian surface.

But Mars has since lost much of its atmosphere, which means water can't stay liquid for long on the surface today.

"The main lake is surrounded by smaller bodies of liquid water, but because of the technical characteristics of the radar, and of its distance from the Martian surface, we cannot conclusively determine whether they are interconnected.".

"The interpretation that best reconciles all the available evidence is that the high intensity reflections (from Mars) are coming from extended pools of liquid water," said co-author Sebastian Lauro, also from Roma Tre University.

There's not enough heat at these depths to melt the ice, so scientists believe the liquid water must contain high concentrations of dissolved salts.

In fact, recent experiments have shown that water with dissolved salts of magnesium and calcium perchlorate (a chemical compound containing chlorine bound to four oxygens) can remain liquid at temperatures of -123C.

"These experiments have demonstrated that brines can persist for geologically significant periods of time even at the temperatures typical of the Martian polar regions (considerably below the freezing temperature of pure water)," said co-author Graziella Caprarelli, from the University of Southern Queensland, Australia.

"By finding more of these bodies of water, this means it's something different - it's not a unique phenomenon, it's not a unicorn

He added: "For this reason, they could still retain traces of any life forms that could have evolved when Mars had a dense atmosphere, a milder climate and the presence of liquid water on the surface, similar to the early Earth."