Water frost on Mars volcanoes was discovered “unexpectedly” for the first time

CNN
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A new study has found that the equatorial region of Mars is home to the tallest volcanoes in the solar system, which – in addition to being as tall as three Mount Everest in some cases – likely hides an unexpected frosty phenomenon.

The largest volcano – Olympus Mons – is 16 miles (26 km) high and 374 miles (602 km) in diameter, making it about 100 times larger than the largest volcano on Earth, Mauna Loa, in Hawaii. In fact, the entire Hawaiian island chain could fit on a Martian volcano, According to NASA.

These giants are topped with large calderas, which are bowl-shaped depressions created by the collapse of the volcano’s summit after an intense eruption.

The enormous size of the caldera – up to 75 miles (121 km) wide. — creates a special microclimate inside them. Using cameras mounted on probes orbiting Mars, researchers have observed morning frost forming inside the caldera for the first time.

“Sediments form on the floor of the caldera, but we also see a little bit of frost on its edge. We also confirmed “It’s ice and potential water.”

“It’s important because it shows us that Mars is a dynamic planet, but also that water can be found almost everywhere on Mars.”

The team of more than two dozen researchers observed frost at four volcanoes: Arsia Mons, Askraeus Mons, and Seronios Tholos, as well as Olympus Mons, according to Stady Published Monday in the journal Nature Geoscience.

The sediments are very thin — only one-hundredth of a millimeter thick, or one-sixth of a human hair, according to Valentinas — but they are spread over such a large surface area that they reach a lot of water. “Based on rough estimates, there are about 150,000 metric tons of water ice, the equivalent of 60 Olympic-size swimming pools,” he said.

To monitor the sediments, the team first looked at about 5,000 images taken by… Cassis – The University of Bern’s Color and Surface Stereo Imaging System – a high-resolution camera that has been imaging Mars since 2018. It is among the instruments on board the spacecraft. ExoMars gas tracking vehiclea spacecraft launched in 2016 in cooperation between the European Space Agency and the Russian space agency Roscosmos.

“This is also the first discovery coming from CaSSIS, which is very exciting,” Valentinas said.

The team validated its observations using two other instruments: NOMAD, a spectrometer also on board the Trace Gas Orbiter, and HRSC, or High Resolution Stereo Camera, an older camera on board the ESA Mars Express, a spacecraft launched in 2003.

Valentinas says the discovery came about with a degree of chance, because he was originally looking for carbon dioxide frost but didn’t find any. The sediments have not yet been monitored because they only form during the early morning and in the colder months, making the observation window narrow.

However, it is unlikely that human astronauts on Mars will ever be able to harvest frost. “It will be very difficult, because even though they are large deposits, they are also very thin and ephemeral, which means they are only present during the night and early morning, and then they are blown back into the atmosphere,” Valentinas said.

Valentinas said the volcanoes are located near the equator of Mars, the warmest region on the planet, which makes the discovery of water particularly interesting.

“Mars is a desert planet, but there is water ice in the polar caps, and there is water ice in the mid-latitudes. Now we also have water frost in the tropics, and the tropics are generally quite dry. So this was completely unexpected,” he said.

He added that in the past, when Mars had a thicker atmosphere and a different climate, there might have been that Glaciers On these volcanoes. The team now wants to expand the search for frost to include more than a dozen named volcanoes on Mars.

If humans are to explore the Red Planet, we will need to know where water is found, so the Martian water cycle is an important area of ​​study, said John Bridges, a professor of planetary science at the University of Leicester in the US. Kingdom, who did not participate in the study.

“This paper is a remarkable use of the CaSSIS camera on the ExoMars Trace Gas Orbiter, which gives visible color and infrared light reflected from the surface of Mars,” Bridges said, calling the results “a remarkable achievement.”

In addition, the water cycle on Mars is not as active as it was billions of years ago, so it is difficult to measure how water moves around the surface, noted J. Taylor Perron is the Cecil and Ida Green Professor of Earth, Atmospheric and Ocean Sciences. Planetary Science at MIT. Perron was also not affiliated with the new research.

“If the frost on these volcanoes is confirmed to be water (and not carbon dioxide), it would be surprising,” he said.

Perron added that everywhere on Mars is cold and dry, but the area around the equator is drier and less cold than the poles, so it is one of the last places you would expect to see water frost. It would also raise the question of where the water vapor that forms the frost comes from, he concluded, from volcanoes, even though they are dormant, or from much further away, such as the polar ice caps.