The analysis of the subsoil led to the discovery of a huge reserve of frozen water under the North Pole of the red planet.
The amount of ice trapped between layers of underground sand is such that if it melts it could submerge the entire planet!
"It was a big surprise for us too," explains Stephen Nerozzi, of the University of Austin, Texas, lead author of the discovery.
A "lasagna" of sand and ice
The ice reserve has been located within several layers of water mixed with sand formed over millions of years, and extends over two kilometers below the planet's surface: it is more than double that assumed in a study carried out in the past weeks and not yet widespread on a large scale.
The study was published in the journal Geophysical Research Letters and it is the result of the analysis made by SHARAD, the depth radar supplied to the Mars Reconnaissance Orbiter.
The volume of water compared to that of sand varies from 61% to 88%: it is as if the entire surface of Mars could be covered by a small sea one and a half meters deep: it is a gigantic quantity.
Near the Martian North Pole, the layers of water also extend for 40 kilometers, and alternate with "thin" layers of sand ranging from 50 to 100 meters deep: they are the result of different periods that have seen the global temperature of the planet rise or fall, and therefore will also be an excellent system for recording how ( and when) the Martian climate has changed in the last million years.
The discovery now changes the entire perception of the planet in relation to its availability of water: it is likely that it is also found in different other latitudes and that it is really, really a lot.
Good news for the "settlers" of the coming years, therefore, were it not for the difficulty of reaching some of these underground "deposits", especially those over two kilometers deep.
