Frost is discovered on Mars volcanoes where it was thought impossible for ice to exist

A team of scientists has discovered frost on the Tharsis volcanoes on Mars – the highest in the Solar System – located near the planet's equator, a place where it was believed impossible for ice to exist. The discovery has cast doubt on hypotheses about the climate dynamics of the red planet.

“We thought it was unlikely that frost would form around the equator of Mars, since the mixture of sun and thin atmosphere keeps temperatures relatively high during the day, both on the surface and on top of mountains, unlike what we thought. “We see on Earth, where you might expect to see icy peaks.”explains Adomas Valantinas, who led the study as a doctoral student at the University of Bern, Switzerland.

But its existence shows that there are “exceptional processes at play that allow the formation of frost,” the researcher acknowledges.

Valantinas believes that “What we are seeing may be a remnant of an ancient climate cycle on modern Mars, where there was precipitation and perhaps even snowfall on these volcanoes in the past.”

Water on Mars

Understanding where water may be on Mars and how it behaves is important for future missions and for human exploration on that planet.

To find out more about all this, the European Space Agency (ESA) has the Trace Gas Orbiter (TGO) of the ExoMars mission, which is equipped with the Mars Surface Color and Stereoscopic Imaging System (CaSSIS), which since April 2018 has been observing Mars and sending high-resolution color images of the planet's surface.

Thanks to these images, the team led by Valantinas has been able to discover Martian frost for the first time very close to the planetary equator.

According to the study, whose details were published this Monday in the journal Nature Geoscience, The frost only lasts a few hours after sunrise, before evaporating in sunlight, and is extremely thin, one hundredth of a millimeter thick, or as wide as a human hair.

Nevertheless, It is estimated that this frost occupies a very vast area that hides some 150,000 tons of water that pass from the surface to the atmosphere every day during the cold seasons, the equivalent of about sixty Olympic swimming pools.

The colossi of Mars

Tharsis, the region of Mars where the frost was found, is home to numerous volcanoes, many of them colossal, rising above the surrounding plains to heights ranging from one to two times that of Earth's Mount Everest. Mount Olympus, for example, is as wide as France.

Frost settles in the calderas of volcanoes, which are large cavities in their summits created during past eruptions. Researchers propose that the way air circulates above these mountains creates a unique microclimate that allows the thin patches of frost to form.

The team believes that modeling how frost forms could help unlock secrets about Mars, such as understanding where water exists and how it moves, as well as understanding the planet's complex atmospheric dynamics, essential for future exploration and the search for possible signs of life. .

The team also detected the frost thanks to CaSSIS images that were validated by independent observations from the High Resolution Stereo Camera on board ESA's Mars Express probe and the Nadir and Occultation for Mars Discovery spectrometer on board the probe. Trace Gas Orbiter.

For it, More than 30,000 images were analyzed both to initially find the frost and to confirm its existence.

The team filtered the images based on where and when they were taken, such as time of day and season, which helped them isolate spectral signatures indicative of water frost and location on the Martian surface. where it was formed.