There is no shortage of water on Mars. Astronomers believe that under the dusty regolith of the planet no less than 5 million cubic kilometers of ice are. In the nineteenth century, the American astronomer Percival Lowell popularized the idea that channels cross the surface of Mars and carry water from the poles.
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The best telescopes and the advent of space probes in the 1960s showed channels like a mirage. Low temperature of Mars and the weak pressure of its thin atmosphere means that no liquid water will remain on the surface. In 2006, seasonal changes in a pair of Martian craters have led astronomers to suggest that during the summer of Mars, a small amount of liquid water could be a small bubble on the surface.
Ten years later, this hypothesis remains unproven.
In an article published in the journal Science on July 25, Roberto Orosei of the National Institute of Astrophysics in Italy and his colleagues reported discovering lakes with 20 km of liquid water beneath the surface of the lake Mars, near the southern ice cap. The lake seems to be Marscousin of Lake Vostok, an underground lake in the Antarctic.
Different materials reflect radar waves with different intensity. The team used radar sensors on the Mars Express spacecraft to explore the area 200 km south of the planet's Arctic Plains. After more than three years of data collection, Dr. Orosei pretty confident that water is the only explanation for the evidence team.
The fact that the lake is underground is the key to its conservation, says Suzanne Spencer. a planetary scientist from the Open University in the UK. As in Antarctica, the thickness of the ice cover isolates the water from freezing on the surface of the planet. At the same time, the pressure of ice, lowers the freezing point of water below 0 ° C. If the water are "aromatized" salts of sodium, magnesium and calcium, which are all discovered on Mars, the freezing temperature can be further reduced.
The discovery is exciting from a purely geological point of view. But the big question is, can life exist? Life exists in Lake Vostok, although it has been cut off the surface for several tens of millions of years.