European planetary scientists have found topographical evidence in images from the Mars Express probe that several subglacial lakes are hidden under the southern polar cap of the fourth planet in the solar system. This discovery contradicts recent statements by their US colleagues about the absence of liquid water on Mars, the press office of the University of Cambridge said on Thursday.
“The combination of radar images, computer models, and the topographical evidence we have obtained is a strong argument that at least one region of liquid water exists under the ice cap of the south pole of Mars. If so, then the interior of the planet must remain geothermally active in order to keep this water from freezing.Neil Arnold, a professor at the University of Cambridge (UK), said.
In July 2018, Italian astronomers working with instruments from the European Mars Express probe reported a surprising discovery. They were able to detect on radar images of the south pole of Mars traces of the existence of three subglacial lakes located at a depth of 1.5 km from the surface of the southern ice cap of the planet.
Subsequently, astronomers discovered several more similar anomalies in radar images, which led scientists to actively discuss the nature of these findings. Many planetary scientists immediately doubted these findings and suggested that the instruments of the Mars Express probe discovered deposits of clay or other rocks, and not subglacial lakes of water. This has generated a lot of controversy around radar anomalies.
In particular, at the beginning of 2022, US planetary scientists analyzed images from Mars Express and came to the conclusion that the liquid water reserves discovered by the probe are a kind of “radar mirage”. A group of European astronomers, led by Professor Arnold, have discovered topographical evidence that their fellow skeptics are wrong in their estimates.
As planetologists note, subglacial lakes that exist on Earth have a special effect on the topography of the ice surface in their vicinity. This is due to the fact that these reservoirs reduce the friction force between the base of the glacier and the rocks along which the ice mass moves, as a result of which it “sags” at the point where the under-ice reservoir is invisible to the eye, and then the glacier rises sharply.
Based on similar considerations, Professor Arnold and his colleagues calculated how the glaciers of Mars would behave under similar conditions. Scientists used this information to analyze detailed images of the southern polar cap of the fourth planet in the solar system at the points where Mars Express supposedly discovered subglacial reservoirs.
As it turned out, on the southern polar cap of Mars there are several regions at once with characteristic depressions and rises, similar to how subglacial lakes on Earth influence the topography of the area. The position of many of them coincides with the points where the radars of the Mars Express probe found traces of the existence of lakes. This, according to Professor Arnold and his colleagues, speaks in favor of the fact that liquid water on Mars exists rather than absent.