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Artistic representation of Mars Express on the red planet
(Image: Spacecraft Photo Credit: ESA / ATG medialab; Mars: ESA / DLR / FU Berlin, CC BY -SA 3.0 IGO)
Researchers have long been searching for liquid water on Mars. now
an Italian team is reporting an entire lake.
Researchers found liquid water on Mars for the first time. The lake of about 20 kilometers wide is therefore about 1.5 kilometers under the ice of the South Pole of Mars. This is reported by a team led by Roberto Orosei of the Italian National Institute of Astrophysics in Bologna in the American Journal Science . Liquid water is a prerequisite for life as we know it. Signs of life in the Marssee, however, can not be read from radar observations with Mars Express's spacecraft from ESA.
The debate ends
The observation concludes a decade-long debate about the existence of liquid water on Mars, stresses the American Society for Advancement of Science (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 today.
The radar image
(Image: background map: NASA / Viking, THEMIS background: NASA / JPL-Caltech / Arizona State University, MARSIS data: ESA / NASA / JPL / ASI / Univ.Rome, R. Orosei et al 2018)
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. In the thin Martian air, there is a small amount of water vapor.
Still new traces
In recent years, scientists have already discovered various traces of liquid water on Mars. For example, drops of water were deposited on NASA's Phoenix landing module, and on some of the steep slopes of the red planet, there are seasonal flow patterns that could or would not come from melting ice water. In addition, there are indications that liquid water could form in a thin layer beneath the surface of Mars in some places regularly, but for a short time – but in minute amounts. Image 1 by 8
(Image: NASA / JPL-Caltech / ESA / DLR / FU Berlin / MSSS)
] Permanently, liquid water can not exist on the Martian surface 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. Radar data now confirm this hypothesis. With the probe from the European Space Agency ESA, researchers around Orosei have searched parts of the South Planum Austral region on the red planet. There, they came to a clearly defined area with the same radar signatures as they create lakes hidden under the ice of terrestrial polar regions.
Conditions hostile to life
It is not known whether there may be life in the glacier underground 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. The temperature of the underground lake now discovered, researchers estimate at minus 68 degrees Celsius.
To remain liquid in this freezing cold, the subterranean lake must be filled with salts which can considerably 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 salt content required does not make life easier, but it is known microorganisms of the earth that survive even with high salt concentration.
More lakes possible
The underground oceans on different ice probes of the Jupiter and Saturn planets are currently considered the most promising places for the search 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 to happen on Mars, the authors point out.
( dpa ) /
(mho)
