This vertically exaggerated view shows scalloped depressions in a part of Mars where such textures prompted researchers to check for buried ice, using ground-penetrating radar aboard NASA’s Mars Reconnaissance Orbiter. Image via NASA/JPL-Caltech/Univ. of Arizona

Water ice makes up half or more of an underground layer in a large region of Mars about halfway from the equator to the planet’s north pole, scientists say. The amount of water in this deposit is about as much as in Lake Superior, which holds 10 percent of Earth’s surface fresh water and by volume is Earth’s third-largest lake, behind Lake Baikal in Siberia and Lake Tanganyika in eastern Africa. A radar aboard NASA’s Mars Reconnaissance Orbiter assessed the amount of water present. The research was published September 26, 2016 in the journal Geophysical Research Letters.

The presence of water underground in this region may have implications for future human explorations of Mars.

Lake Superior holds about 3 quadrillion gallons of water – that’s 3,000,000,000,000,000, or a thousand trillion, gallons – enough water to cover both North and South America under a foot (0.3 meters) of water. Source: Just how big is Lake Superior?