The ExoMars probe discovered large reserves of ice in one of the deep canyons located in the center of the Mariner valleys of Mars. The results of the study were published by the scientific journal Icarus.
“The TGO probe can search and study “oases” of Martian water, hidden under a multimeter layer of dust and soil, which in the past we simply could not detect. In particular, the FREND device discovered an area in the system of canyons in the Mariner valleys, 40% of the surface of which is covered with deposits of ice”, – said one of the study authors, head of the Department of Nuclear Planetology Institute of Space Research Igor Mitrofanov.
The Mariner Valleys were discovered by Mariner-9 probe
The Mariner Valleys is a giant system of canyons in the southern hemisphere of Mars. In the early 1970s, it was discovered by the American Mariner-9 probe. Their length scientists estimate about 4.5 thousand km, and a depth of about 11 km. That is, the Mariner valleys – the largest canyon on all the planets of the solar system.
For quite a long time, scientists have suggested that the darkest corners of the Mariner valleys may hide a lot of ice. However, until recently, it was not possible to find unambiguous traces of their existence. Planetary scientists from Russia and the Netherlands, led by Mitrofanov, have coped with this task.
The FREND neutron spectrometer onboard the ExoMars probe played a key role in the discovery. It can pick up traces of water and other hydrogen compounds in the interior of Mars by the way they interact with the cosmic neutron flux. A year ago, FREND already detected several “water oases” on the slopes of volcanoes at the equatorial latitudes of Mars, where ice was not supposed to exist.
Mitrofanov and his colleagues analyzed FREND data from their 2018-2021 flyby of the Mariner Valleys. It turned out that one of the central regions of these canyons, which planetary scientists call the “Chaos of Candor,” harbors significant reserves of water ice.
Astronomers estimate that the proportion of water in the near-surface rocks of “Chaos Kandor” is at least 40%. That is, it is there in the form of pure ice, and not hidden inside any minerals. That is, this part of the Mariner valleys is particularly interesting to study, including during future robotic and manned expeditions to Mars.
Of particular interest to scientists, as noted by Mitrofanov and his colleagues, is how the water ice remains stable in this part of Mars, where its deposits must gradually evaporate and volatilize into space. This suggests either unique climatic and geological conditions in the Mariner valleys, or evidence that local water supplies are constantly being replenished, the scientists concluded.