CNN
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The equatorial region of Mars is home to the tallest volcanoes in the solar system, which, in addition to rising as high as three Mount Everests in some cases, are likely hiding an unexpected freezing phenomenon, according to a new study.
The largest, Olympus Mons, is 26 kilometers high and 602 kilometers in diameter, making it about 100 times larger than Earth’s largest volcano, Mauna Loa, in Hawaii. In fact, the entire Hawaiian island chain would fit inside the Martian volcano, according to NASA.
NASA/JPL/MSSS
The study results suggest that water can be found almost everywhere on the surface of the Red Planet, said lead author Adomas Valantinas.
These giants are topped by large calderas, bowl-shaped depressions caused by the collapse of the volcano’s summit after an intense eruption.
The sheer size of the calderas – up to 121 kilometers in diameter – creates a special microclimate inside them. Thanks to cameras installed on probes orbiting Mars, researchers observed for the first time the formation of morning frost inside the calderas.
“The deposits form on the bottom of the caldera, but we also see some frost on its edge. We also confirmed that it was ice and probably water,” said Adomas Valantinas, a postdoctoral researcher at Brown University who made the discovery as a doctoral student at the University of Bern, Switzerland. and lead author of the study.
“This is important because it shows us that Mars is a dynamic planet, but also that water can be found almost everywhere on the Martian surface.”
The team of more than twenty researchers spotted frost on four volcanoes: Arsia Mons, Ascraeus Mons and Ceraunius Tholus, as well as Olympus Mons, according to the study published Monday in the journal Nature Geoscience.
The deposits are extremely thin – just a hundredth of a millimeter thick, or one-sixth of a human hair, according to Valantinas – but they are spread over such a large area that they represent a large amount of water. “According to rough estimates, this represents around 150,000 tonnes of water ice, the equivalent of 60 Olympic swimming pools,” he said.
To observe the deposits, the team first examined around 5,000 images taken by CaSSIS – the University of Bern’s Color and Stereo Surface Imaging System – a high-definition camera that has been photographing Mars since 2018. It part of the instruments on board the ExoMars Trace Gas system. Orbiter, a spacecraft launched in 2016 as part of a collaboration between the European Space Agency and the Russian space agency Roscosmos.
“This is also the first discovery coming from CaSSIS, which is very exciting,” Valantinas said.
The team validated their observations with two other instruments: NOMAD, a spectrometer also aboard the Trace Gas Orbiter, and HRSC, or High Resolution Stereo Camera, an older camera aboard ESA’s Mars Express orbiter. a spacecraft launched in 2003.
ESA/DLR/FU Berlin
This image of Olympus Mons was taken early in the morning (7:20 a.m. local solar time) by the stereo camera aboard ESA’s Mars Express, as part of new research revealing freezing of Olympus for the first time. water near the equator of Mars, part of the planet. where freezing was thought to be impossible.
Valantinas says the discovery came with some serendipity, as he was originally looking for carbon dioxide frost but found none. The deposits have not been spotted until now because they only form early in the morning and during colder months, making the observation window narrow.
However, it is unlikely that frost could ever be harvested by human astronauts on Mars. “It would be quite difficult because although it is a large deposit it is also very thin and ephemeral, meaning it is only there during the night and early morning and then it sublime again in the atmosphere,” Valantinas explained.
The volcanoes are near Mars’ equator, the hottest area on the planet, making the water discovery particularly intriguing, Valantinas said.
“Mars is a desert planet, but there is water ice in the polar ice caps and water ice in the mid-latitudes. Today we also have freezing water in the equatorial regions, and the equatorial regions are generally quite dry. So it was quite unexpected,” he said.
He added that in the past, when Mars had a thicker atmosphere and a different climate, there might have been glaciers on these volcanoes. The team now wants to expand the search for the gel to more than a dozen named volcanoes on Mars.
If humans are ever going to explore the Red Planet, we’ll need to know where the water is. The Martian water cycle is therefore an important area of study, said John Bridges, professor of planetary sciences at the University of Leicester in the United States. Kingdom, which did not participate in the study.
“This paper is a fantastic use of the CaSSIS camera on the ExoMars Trace Gas Orbiter, which gives both visible color and infrared light reflected from the Martian surface,” Bridges said, calling the results a “remarkable achievement.” .
Additionally, the water cycle on Mars is nowhere near as active as it was billions of years ago, so it’s difficult to measure how water moves around the surface, noted J. Taylor Perron, Cecil and Ida Green Professor of Earth, Atmosphere and Planetary Sciences at the Massachusetts Institute of Technology. Perron was also not affiliated with the new research.
“If the gel on these volcanoes is confirmed to be water (and not carbon dioxide), that would be surprising,” he said.
Everywhere on the surface of Mars is cold and dry, Perron added, but the area around the equator is drier and less cold than the poles, so it’s one of the last places to be. expect to see water frost. This would also raise the question, he concludes, of knowing where the water vapor that forms the frost comes from: volcanoes, even if they are dormant, or from much further away, like the polar ice caps.