Using high-resolution color images from the European Space Agency’s (ESA) Trace Gases Orbiter (TGO) and Mars Express missions, planetary researchers have found evidence of morning frost deposits in the calderas of the Tharsis volcanoes on Mars (Olympus Mons, Arsia Mons, Ascleius Mons and Ceraunius Turus).
This image, taken with the High Resolution Stereo Camera on ESA’s Mars Express spacecraft, shows Olympus Mons, the tallest volcano not only on Mars but in the entire Solar System. Image credit: ESA / DLR / Free University Berlin.
The Tharsis region of Mars contains numerous volcanoes, including Olympus Mons and the Tharsis Mountains (Ascraeus Mons, Pavonis Mons, and Arsia Mons).
Many of these volcanoes are enormous, towering above the surrounding plains at heights between one (Mont Pavonis) and three times (Mont Olympus) higher than Earth’s Mount Everest.
At the summit of these volcanoes are large cavities called calderas, which were formed when magma chambers were emptied during past eruptions.
“We thought it would be impossible for frost to form near the equator on Mars because of the relatively high temperatures both on the surface and on mountain tops, caused by a combination of sunlight and a thin atmosphere. On Earth, we would expect frost to form on mountain tops, but that would not be the case near the equator on Mars,” said Dr. Adomas Valantinas, a postdoctoral researcher at Brown University.
“Its presence here is intriguing and suggests that there are exceptional processes at work that allow frost to form.”
The frost patches appear for a few hours before and after sunrise, then evaporate in the sunlight.
Although it is thin, perhaps only one-hundredth of a millimeter thick (about the thickness of a human hair), it covers a vast area.
The amount of frost is equivalent to about 150,000 tonnes of water that moves between the earth’s surface and the atmosphere every day during the cold season, which is roughly the equivalent of filling about 60 Olympic swimming pools.
The researchers propose that air circulates in a special way above Tharsis, creating a unique microclimate within the volcano’s caldera there and allowing the frost patches to form.
“Winds move up the mountain slopes, carrying relatively moist air from close to the surface to higher altitudes, where it condenses and falls as frost,” said Dr Nicolas Thomas from the University of Bern, principal investigator of TGO’s Colour Stereo Surface Imaging System (CaSSIS).
“We actually see this happening on Earth and other parts of Mars, where the same phenomenon causes the seasonal elongated clouds on Mars’ Arsia Mons.”
“The frost we see on the summits of Martian volcanoes appears to have accumulated in the shadowed parts of the calderas, where temperatures are particularly cool.”
Scientists have found frost on the Tharsis volcanoes of Olympus, Arsia, Mount Ascraeus and Ceraunius Turus.
By modeling how these frosts form, scientists could potentially unlock more of Mars’ mysteries, like where any remaining water on Mars resides, how it moves between reservoirs, and even understanding the dynamics of the planet’s complex atmosphere.
This knowledge is essential for future exploration of Mars and the search for signs of extraterrestrial life.
“The discovery of water on the surface of Mars is always an exciting prospect, both for scientific interest and for its implications for human and robotic exploration,” said Dr Colin Wilson, ESA’s project scientist for both ExoMars TGO and Mars Express.
“Even so, this discovery is particularly intriguing because Mars’ low atmospheric pressure creates the unusual situation where Martian mountaintops are typically less cold than the plains. But moist air blowing up the mountain slopes can still condense into frost, a phenomenon that is clearly similar to Earth.”
“This discovery was made possible thanks to successful collaboration between ESA’s two Mars rovers, as well as additional modelling.”
“Understanding exactly which phenomena are the same and which are different on Earth and Mars will really test and improve our understanding of the fundamental processes occurring not only on our home planet but elsewhere in the universe.”
of Investigation result Published in the journal Nature Chemistry.
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A. Valantinus othersEvidence for episodic morning frost accumulation at the Tharsis volcano, Mars. National GeographyPublished online June 10, 2024; doi: 10.1038/s41561-024-01457-7
Source: www.sci.news
