Layers of the South Pole of Mars

Explanation: What lies beneath the layered south pole of Mars? A recent measurement with ground-penetrating radar from ESA's Mars Express satellite has detected a bright reflection layer consistent with an underground lake of salty water . The reflection comes from about 1.5 kilometers down and covers an area 20 kilometers across. Liquid water evaporates quickly from the surface of Mars , but a briny confined lake , such as implied by the radar reflection, could last much longer and be a candidate to host life such as microbes . Pictured , an infrared , green, and blue image of the south pole of Mars taken by Mars Express in 2012 shows a complex mixture of layers of dirt, frozen carbon dioxide , and frozen water .