the icy cap that covers Mars’ south pole, composed of frozen water and carbon dioxide.

Mars’s south pole may have an underground lake surrounded by ponds

The ice cap that covers Mars’s south pole is composed of frozen water and carbon dioxide

ESA/DLR/FU Berlin / Bill Dunford

A lake of liquid water surrounded by smaller ponds may be buried under 1400 metres of ice near the south pole of Mars. Radar observations had already suggested that there may be a lake, but new measurements have provided more evidence of its existence and may have found even more liquid water nearby.

The European Space Agency’s Mars Express spacecraft has been orbiting the planet since 2003. Elena Pettinelli at Roma Tre University in Italy and her colleagues …