The new information from a probe in orbit around Mars (Mars Express) seems to reinforce the 2018 claim that there is a lake about 1.5 kilometers under the ice of Mars, near the south pole. A salty lake. The spacecraft emits radar pulses that are reflected in the underground material and in that year they discovered the lake using 29 observations of the areas and doing intelligent information processing. Now, the analysis of the new data collected, carried out by some of the same researchers from the previous find, also hints at several more bodies of water that surround the main reservoir , according to the authors in their study published in the journal Nature Astronomy.
If it finally exists, the central lake would cover approximately 600 square kilometers . To avoid freezing, the water would have to be extremely salty, possibly making it similar to the subglacial lakes of Antarctica, here on Earth.
“This area is the closest thing to ‘habitable’ on Mars that has been found so far,” says Roberto Orosei, a planetary scientist at the National Institute of Astrophysics in Bologna.
The experts used techniques that had previously been used to study subglacial lakes beneath the Antarctic and Greenland ice sheets. However, studying lakes on another planet is … something else. Observations on Earth are made by plane, 500 meters above the ice, while MARSIS (the instrument for surveying the Martian subsurface and ionosphere) operates at an average altitude of 400 kilometers.
“While it is not possible for water to remain stable on the surface today, the new result opens up the possibility that an entire system of ancient lakes exists underground, perhaps millions or even billions of years old. They would be ideal locations. to look for evidence of life on Mars, although very difficult to reach, “the experts explain.
A network of subglacial lakes separated by dry stone regions
If it’s liquid water, it’s probably salt water. Since it is so cold on Mars, even though the interior is warmer than the surface, it is still cold enough to freeze fresh water. In 2018, the team estimated that the lake would be around -68 ° C.
But salt lowers the freezing point of water and can do so significantly. For this reason, water impregnated with calcium and magnesium salts can remain liquid at such low temperatures for very long periods of time. And Mars is also rich in calcium and magnesium salts, in addition to sodium.
Researchers are increasingly convinced that more water is likely trapped under the ice at the South Pole of the Red Planet.
How were these lakes formed?
The assumption that geothermal activity had melted the polar ice to form underground lakes is no longer plausible when finding various lake formations. But they could have originated due to a warmer global climate in the Martian past.
In the future, scientists would like to look for similar networks of lakes in other parts of the south pole, and perhaps the planet’s north pole as well.
Referencia: Multiple subglacial water bodies below the south pole of Mars unveiled by new MARSIS data, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1200-6 , www.nature.com/articles/s41550-020-1200-6
