By Stephen Beech via SWNS
Water in the form of frost has been detected on the highest volcanoes on Mars.
Researchers found that the red planet’s Tharsis volcanoes – the tallest in the solar system – have “on and off” patches of water frost in what the international team described as a “significant” first.
They say their discovery, described in the journal Nature Geoscience, challenges previous assumptions about the Martian climate – and is a major breakthrough in the search for lifeforms on other planets.
Study leader Dr. Adomas Valantinas, of Brown University, Rhode Island, said: “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.
“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.”
The study suggests that the frost is present for only a few hours after sunrise before it evaporates in sunlight.
Dr. Valantinas says the frost is also “incredibly” thin – likely just one-hundredth of a millimeter thick or about the width of a human hair.
The researchers calculate the frost constitutes at least 150,000 tons of water that swap between the surface and atmosphere each day during the cold seasons – the equivalent of around 60 Olympic-size swimming pools.
Tharsis, the region of Mars where the frost was found, hosts several volcanoes. They tower above the surrounding plains at heights ranging from one to two times that of Mount Everest while Olympus Mons is as wide as France.
Dr. Valantinas says the frost sits in the calderas of the volcanoes, which are massive hollows at their summits created during previous eruptions.
The research team propose that the way the air circulates above these mountains creates a “unique” microclimate that allows the thin patches of frost to form.
They believe modeling how the frosts form could allow scientists to reveal more of Mars’ remaining secrets, including understanding where water exists and how it moves, as well as understanding the planet’s complex atmospheric dynamics, which is essential for future exploration and the search for possible signs of life.
The team detected the frost using high-resolution colour images from the Colour and Stereo Surface Imaging System (CaSSIS) onboard the European Space Agency’s Trace Gas Orbiter.
The findings were then validated using independent observations from the High-Resolution Stereo Camera onboard the ESA’s Mars Express orbiter and by the Nadir and Occultation for Mars Discovery spectrometer onboard the Trace Gas Orbiter.
The study involved analyzing more than 30,000 images to both initially find the frost and then confirm its existence.
Dr. Valantinas, who began analyzing the images in 2018, filtered them based on where they were acquired as well as when they were acquired, including the time of day and the season.
The meticulous approach helped isolate spectral signatures indicative of water frost and where it formed on the surface of Mars.
Dr. Valantinas now plans to look at ancient hydrothermal environments that could have supported microbial life on Mars.
He says samples from these environments may one day be brought back to Earth by the NASA-lead Mars Sample Return mission.
Dr. Valantinas, who began the work as a doctoral student at the University of Bern in Switzerland, added: “This notion of a second genesis, of life beyond Earth, has always fascinated me.”
