The MRO probe instruments helped scientists to measure the amount of water ice on Mars hidden beneath the soil on one of the planet’s plains, whose cumulative mass was comparable to the amount of water in the Great Lake, the largest freshwater body of the Earth, according to an article published in the journal Geophysical Research Letters.
“The water in these deposits is likely to be more accessible to us than other ice deposits on Mars, since it is located at rather low latitudes and is located on a fairly flat and level plain, where it is much easier to land a spacecraft than in other regions with underground ice reserves, “said Jack Holt of the University of Texas at Austin, USA.
In recent years, scientists have found many hints that on the surface of Mars in ancient times there were rivers, lakes and entire oceans, containing almost as much liquid as our Arctic Ocean.
At the same time, some planetary scientists believe that even in ancient times Mars could be too cold for the constant existence of the oceans, and its water could be in a liquid state only at the time of volcanic eruptions.
Recent observations of Mars with ground-based telescopes have shown that in the past 3.7 billion years the planet lost an entire ocean of water, which would be enough to cover the entire surface of the red planet with a 140-meter-thick ocean. Where this water disappeared, scientists are trying to find out today.
Holt and his colleagues found one possible trace of this “missing” water, studying unusual structures on the surface of the plain of Utopia, located in the middle latitudes of Mars, using the instruments of the probe MRO, studying the red planet since 2005.
As scientists explain, unusual “holes”, cracks and structures resembling cracked soil or a set of polygons, made them suspect that under the given plain, considerable water reserves can hide. Similar forms of relief, according to planetologists, can be seen in those regions of Canada and other northern countries where there are zones of permafrost.
They tested this idea with the help of the SHARAD radar onboard the MRO, which allows to scan the ground for several hundred meters and determine its chemical composition and structure. Premonitions have not deceived the planetologists – under the Utopia plain, a whole sea of water, roughly equal in area to the Caspian Sea or to a large European state, really hides.
It is a giant glacier about 80-170 meters thick, 85% of water, and 15% of dust or large cobblestones. The volume of water in it, according to researchers, is not inferior to how much moisture is contained in Lake Great, the largest freshwater pond in North America and the Earth.
This water, according to researchers, was able to “survive” on the modern dry Mars and not evaporate into space thanks to a 10-meter “crust” of dust and soil covering it from the atmosphere of the red planet. Scientists suggest that this glacier was formed in the distant past at the time when the axis of Mars was tilted to the other side, and the plain of Utopia was closer to the poles of the planet.
As noted by planetologists, this “secret sea” represents only 1% of the total volume of water ice, but its discovery actually doubles the known reserves of underground ice in the northern hemisphere of Mars. In addition to the obvious “colonization” goals, these same ice reserves can be used to uncover the secrets of the Mars climate in the past, Holt and his colleagues conclude.