Water frost detected on Mars' volcanoes in 'significant' first discovery: Study

Planetary researchers announced a major discovery from the solar system's Red Planet on Monday – patches of water frost equating to "60 Olympic-size swimming pools" have been detected on Mars.

The thin yet widespread layers of water frost were discovered atop three of Mars' Tharsis volcanoes, located on a plateau at the planet's equator, according to a new study published in the journal Nature Geoscience.

The Tharsis volcanoes, a string of 12 large peaks, are the tallest volcanoes in our solar system, according to the study, which notes that the water frost was discovered on the volcanoes Olympus, Arsia Ascraeus Mons, and Ceraunius Tholus.

"The researchers calculate the frost constitutes at least 150,000 tons of water that swaps between the surface and atmosphere each day during the cold seasons," researchers from Brown University reported in a press release Monday, adding, "That's the equivalent of roughly 60 Olympic-size swimming pools."

The European Space Agency's ExoMars and Mars Express missions orbiting the planet captured over 30,000 images of the water frost, which were then analyzed by a team of international researchers, according to the study.

Researchers discovered that the thin layer of frost – approximately "one-hundredth of a millimeter thick or about the width of a human hair," according to the study – forms during sunrise and then evaporates during daylight hours.

"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," Adomas Valantinas, a postdoctoral fellow at Brown University who led the study, said in a press release.

"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," Valantinas said.

The water frost sits in the calderas of the volcanoes, which are massive depressions at the top of the summit that formed after past eruptions, according to the study.

Researchers hypothesize the air circulating above the calderas creates a "unique microclimate that allows the thin patches of frost to form."

The findings challenge scientists' previous understanding of Mars' climate and offer an exciting avenue for further Martian exploration, according to researchers.

Valantinas, who began analyzing the images in 2018, said, "This notion of a second genesis, of life beyond Earth, has always fascinated me."