The South Pole of Mars contains enough ice to cover the planet in 35 feet (11 meters) of water if it melted, new radar scans have determined. The north pole, researchers said, probably holds about as much.

While scientists have known for some time that Mars has large amounts of ice at its poles, the newest measurements are said to be the most precise and revealing. They found, for instance, that some of the ice deposits are more than two miles thick, and that the crust beneath the ice sheet is often rugged and cratered.

The finding suggests the existence of liquid water at the bottom of the South Pole.

The warmer temperatures required to melt the ice would probably come from geothermal heat deep within the planet.