Mars Express, one of the orbiting satellites at Mars, has discovered huge water deposits under the surface. Using the radar sounder, known as MARSIS, large expanses of water as ice in layered deposits surrounding the North Polar Cap were found. Scientists believe that an almost pure glacier of water ice about one mile thick underlies the surface beyond the polar cap’s outer margin.

At the South Pole, MARSIS discovered buried water ice that extends about two miles deep in some places. That ice appears to be very pure too.

Another huge quantity of ice may be under the surface of a large plain located beyond the South Polar Cap called Dorsa Argentea. It covers about 2,000,000 square miles, or about 2% of the surface of Mars. The ice is stacked to depths up to 1,600 feet. If it is all water ice, it’s enough water to cover the entire surface of Mars to a depth of about 30 feet.

Mars Odyssey, another orbiting satellite, discovered that ice lies less than three feet below the surface everywhere from 60 degrees latitude to 90 degrees latitude, reaching to the North and South Poles in both hemispheres. Scientists believe the ice may be the tip of a vast, underground iceberg.

In the next few months, the Mars Reconnaissance Orbiter (MRO) will use its radar capabilities to study the ice further. MRO has a very sensitive radar sounder and it may be able to reveal more information about the subterranean, or underground, icebergs. MRO went into orbit around Mars on March 10th.