Unprecedented find in the mountains of Mars

It is the first time that deposits of frozen water have been detected, the tallest mountains of Mars, the Tharsis volcanoes, the largest in the solar system that rise up to three times the height of the Everest, in the equatorial part of the planet. Due to there location, this frost formation was not expected, being found at lower latitudes on the planet.

During the coldest months, a layer of ice thinner than a human hair forms in the craters of volcanoes and in sections of their rims. Subsequently, it evaporates a few hours after sunrise. Despite the thinness of this layer, it covers a very large surface area. In fact, scientists estimate that in the coldest seasons on Mars, 150,000 tons of water, equivalent to 60 Olympic swimming pools, condense daily on the tops of these mountains.

The first time water ice has been found in the equatorial regions of Mars

This study has just been published in the journal Nature Geoscience and has been carried out by the team led by the University of Bern (Switzerland), thanks to the Martian camera CaSSIS, on board the ExoMars Trace Gas Orbiter probe of the European Space Agency (ESA). Adomas Valantinas, one of the scientists at the University of Bern, states in an ESA press release that “we thought it was impossible for frost to form around Mars’s equator, as the mix of sunshine and thin atmosphere keeps temperatures relatively high at both surface and mountaintop.”

To identify the frost, the team of scientists analyzed more than 5,000 images taken by this camera since April 2018. The CaSSIS has provided observations of local dust activity, seasonal changes in CO2 ice deposits and the existence of dry avalanches on Mars.

This study was corroborated by using independent observations from the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express orbiter and the Nadir and Occultation for Mars Discovery (NOMAD) spectrometer aboard the TGO.

It is not the first time that water has been found on Mars

Spacecraft orbiting Mars have on other occasions transmitted evidence of frozen and liquid water on the red planet, with more considerable amounts at the north and south poles. Based on the landscape, scientists predict that the planet was once wetter and even habitable, full of giant lakes and rivers. “What we’re seeing may be a remnant of an ancient climate cycle on modern Mars, where you had precipitation and maybe even snowfall on these volcanoes in the past,” says Valantinas.

Scientists considered this finding unlikely

The frost appears as a bluish tone at the bottom of the volcano and is not perceived on its well-lit slopes. Despite this discovery, scientists considered it unlikely that frost could form on the tops of the volcano due to sunlight and the thin atmosphere of the red planet.

Both of these conditions maintain temperatures very high throughout the day, at the tops as well as at ground level. However, in the Nature Geoscience article, these scientists state that winds can transport humid air from the slopes of mountains to the calderas of volcanoes, where it condenses. and settles in the form of frost.

The Tharsis region on Mars is a vast volcanic plateau near the planet’s equator. It is home to a dozen large volcanoes, including Pavonis Mons and Olympus Mons, which at more than 8.6 and 16 miles high, respectively, are almost two and three times higher than Everest. Olympus Mons is much wider than it is high and covers an area the size of France.