frost-detected-on-martian-mountains

Researchers have detected frost atop volcanoes on Mars, so far considered "improbable" owing to hot temperatures on the planet.

 

The discovery marks the first time that frost has been detected near the planet's equator, challenging current perceptions of the planet's climate, said the international team of researchers, led by those at the University of Bern, Switzerland.

 

The volcanoes in the Mars' Tharsis region, where the frost was observed, are the tallest in the entire solar system. The frost sits in the calderas of the volcanoes, which are large hollows at their summits created during past eruptions, the researchers said.

 

They proposed that the way the air circulates above these mountains, it creates a unique "microclimate" allowing for the thin patches of frost to form.

 

"We thought it was improbable for frost to form around Mars' equator, as the mix of sunshine and thin atmosphere keeps temperatures during the day relatively high at both the surface and mountaintop, unlike what we see on Earth, where you might expect to see frosty peaks," explained Adomas Valantinas, who led the work as a PhD student at the University of Bern.

 

"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," said Valantinas.

 

In their study, published in the journal Nature Geoscience, the researchers described that the frost is present for only a few hours after sunrise before it evaporates in sunlight.

 

Further, at about a hundredth of a millimetre thick, roughly the width of a human hair, the frost is "incredibly thin," yet "quite vast," the authors said.

 

The frost is part of at least 1.5 lakh tons of water cycling between the surface and air each day during the cold seasons -- about the same as 60 Olympic-size swimming pools, they said.

 

The Tharsis region on Mars hosts numerous volcanoes, which tower above the surrounding plains at heights ranging from one to two times that of Earth's Mount Everest. Olympus Mons, for instance, is as wide as France, the researchers said.

 

They said that modelling how frosts form could help scientists understand Mars's other secrets, including those about the existence of water, along with those of the planet's atmosphere.

 

The knowledge is essential for future exploration and the search for possible signs of life, they said.

 

For the study, the researchers analysed more than 30,000 images obtained from the Colour and Stereo Surface Imaging System (CaSSIS) onboard the European Space Agency's (ESA's) Trace Gas Orbiter (a spacecraft). The findings were validated through independent observations, including those from the ESA's Mars Express orbiter.

 

The efforts helped in initially finding the frost and then confirming its existence, the researchers said.