Because of the toxic and arid surface of Mars, water cannot thrive on it. However, scientists have discovered that beneath its unaccommodating surface, there lies a massive deposit of underground water ice.

According to the report published in the journal Geophysical Research Letters, the water ice makes up half or more of an underground layer in a large region of Mars about halfway from the equator to the North Pole. For reference, it is larger than Mexico and, if melted, will create enough water to fill the Lake Superior -- the largest of the Great Lakes in North America and, by volume, is the Earth's third largest lake.

Earth Sky reported that researchers assessed data on part of Mars' Utopia Planitia region, as obtained by a ground-penetrating radar instrument on NASA's Mars Reconnaissance Orbiter. Utopia Planitia is a basin with a diameter of about 3,300 kilometres, Top Examiner said.

The deposit ranges in thickness from about 260 feet (80 meters) to about 560 feet (170 meters), with a composition that's 50 to 85 percent water ice mixed with dust or larger rocky particles.

"This deposit probably formed as snowfall accumulating into an ice sheet mixed with dust during a period in Mars history when the planet's axis was more tilted than it is today," said Cassie Stuurman of the Institute for Geophysics at the University of Texas, Austin, lead author of the study, in a press release.

The scientists said that one of the reasons why water is still present in the area is because it is shielded by soil that is about 3 to 33 feet (1 to 10 meters) thick. Because the water ice lies at a relatively low latitude and in a flat and smooth area, it could provide resources to astronauts who will soon go on a Red Planet mission.

The newly discovered deposits represent just less than one per cent of all known water ice on Mars.