A massive underground lake has been detected for the first time on Mars, raising the possibility that more water - and maybe even life - exists there.
According to a report led by Italian researchers in the US journal Science, the lake is about 20 kilometres wide, located under a layer of Martian ice. It is the largest body of liquid water ever found on the Red Planet.
Mars is now cold,
barren and dry but used to be warm and wet. It is believed that the planet was home to plenty of liquid water and lakes at least 3.6 billion years ago.
Scientists are eager to find signs of contemporary water because such discoveries are key to unlocking the mystery of whether life ever formed on Mars in its ancient past, or if it might persist today.