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The researchers say that they first found a lake of liquid water on Mars. The lake, about 20 kilometers wide, is about 1.5 kilometers below the
ice floe of the south pole of Mars.
A team of Roberto Orosei of the Italian National Institute of Astrophysics
reports to Bologna ] in the American journal "Science". Liquid water is a prerequisite for life as we know it. The signs of life in the Marssee, however, can not be inferred from radar observations with the space probe "Mars Express" from the European Space Agency Esa.
The observation concludes a ten-year debate on the existence of liquid water on Mars, says the American Society of Science Promotion (AAAS), publisher of Science. Rivers and dried sediments show that there must have been liquid water on the red planet billions of years ago. At that time, the climate
was warmer and the Martian atmosphere was more dense than it is today. Even an entire ocean could have covered much of the young Mars. For decades, researchers have been looking for liquid water on our neighboring planet. Today, however, water exists on Mars, especially in the form of ice in the polar ice caps. There is a low level of water vapor in Mars' thin air.
In recent years, scientists have discovered various traces of liquid water on Mars. For example, drops of water were deposited on NASA's "Phoenix" lime module, and on some of the steep slopes of the red planet, there are flow patterns that may come from melting ice. In addition, there is evidence that liquid water could form regularly, but briefly, in a thin layer below the surface of Mars in some places, albeit in minute amounts.
The liquid water on the surface of Mars can not exist today. For over 30 years, however, researchers have suggested that under the ice caps, there could be bags of liquid water – similar to the subterranean lakes of Antarctica and Greenland on Earth. The Mars Express radar data now confirm this hypothesis. With the probe
of the European Space Agency Esa researchers around Orosei excavated parts of the South Pole Planum Austral region on the Red Planet. There, they came across a well-defined region with the same radar signatures as they create lakes hidden under the ice of terrestrial polar regions.
It is unclear whether there may be life in the underground glacial lake on Mars. When other explorers buried the underground Whillans Lake in Antarctica on Earth, they encountered many microbes in eternal darkness. However, Whillans Lake is not a closed ecosystem, its waters are slowly but regularly exchanged through an underground river. In addition, it is much colder at the south pole of Mars than at the Antarctic terrestrial. Researchers estimate the temperature of the underground lake now uncovered at minus 68 degrees C.
To remain liquid in this icy cold, the underground lake must be full of salts that can significantly lower the freezing point. Magnesium, calcium and sodium salts are widespread on Mars. It is therefore quite plausible that they also occur in the underground lake, say the researchers around Orosei. The necessary salinity does not make life easier for people, but the Earth is known for its microorganisms that even survive high salt levels.
The underground oceans on different ice orbits on the Jupiter and Saturn planets are currently considered the most promising places for extraterrestrial life. in our solar system. If the underground glacial lake on Mars in this row of rank remains to be seen. It may not be an isolated case: only a fraction of the south pole cap was radar and the method could only prove underground lakes of a certain minimum size in Because of their limited spatial resolution, there is no reason for Mars, the authors point out.
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