Enough water has been discovered on Mars to cover the entire surface of the planet with an ocean 1.5 to 2.7 meters deep.. This conclusion was presented by the scientific mission of the European Space Agency (ESA) Mars Express, which has been exploring the Red Planet for 20 years.. The authors of the discovery claim the largest amount of water ice found on Mars, which seems to be in line with the findings of previous researchers.
Proposed deposits of water ice under the equator of Mars / Image source: Planetary Science Institute
“It is surprising that the radar signals match what we would expect to see from layered ice, and are similar to the signals we see from the polar caps of Mars, which we know are very ice-rich,” lead researcher Thomas said in an EKA statement. Watters (Thomas Watters) from the Smithsonian Institution in the USA.
According to scientists, the thickness of the ice belt, covered with a “crust” of hardened volcanic ash and dry dust, reaches 3.7 km. The ice is not crystal clear, it is heavily contaminated with dust. While the presence of ice near the equator makes it more accessible for future human expeditions, a layer of ice covering several hundred meters thick will make access much more difficult.
About 15 years ago, the Mars Express probe discovered an unusual deposit of soft rock stretching nearly 5,000 km near the equator of Mars.. The formation was named Medusae Fossae Formation (MMF). According to scientists, the formation of MMF was a turning point in the history of Mars. It is assumed that the eruptions that created it released a huge amount of gases and water vapor into the atmosphere, radically changing the climate of the planet.
Medusae Fossae Formation / Image source: Smithsonian Institution
The MMF is believed to have formed over the last 3 billion years from lava flows and was then covered by a thick layer of volcanic ash. Today the MMF is the most abundant source of dust for giant seasonal dust storms. New observations from the Mars Express MARSIS radar suggest that the Medusae Fossae formation contains more than just dust.
“Given the thickness of the layer, if the MFF were just a giant pile of dust, it should have compacted under its own weight, ” says Andrea Cicchetti of Italy’s National Institute of Astrophysics. “ This would create something much denser than what we actually see with MARSIS.”. The sediments are low-density and quite transparent to the MARSIS radar, which is most similar to the signature of water ice.
An area of Mars scanned by the MARSIS radar / Image source: Smithsonian Institution
Water ice on Mars has been discovered many times before.. In 2008, NASA's Phoenix mission discovered ice just beneath a layer of dust at the lander's landing site, and remnants of relict glaciers were discovered in Noctis's Eastern Labyrinth, which lies just 7.3 degrees south of the equator. The presence of underground water ice at low and equatorial latitudes hints at how very different Mars' climate was in the distant past.
The formation of huge deposits of water ice in the equatorial region of Mars may be the result of a change in the tilt of the Red Planet's axis, which changed quite chaotically. Currently, the poles of Mars are tilted to the ecliptic by 25 degrees (Earth's tilt is 23 degrees), but in the past this angle could vary from 10 to an extreme 60 degrees. During periods of strong tilt, when the poles of the planet alternately found themselves much closer to the Sun than the equatorial part of the planet, water ice formed in large quantities near the equator, which was then buried under a layer of ash and dust.
The new discovery is described in an article published in the journal Geophysical Research Letters.