Water frost has been observed on Mars’ equator for the first time. In this region of the Red Planet, similar to the tropics, it was previously thought impossible for frost to exist.
The discovery could be crucial for modeling where water exists on Mars and how it is exchanged between the Red Planet’s atmosphere and its surface. This could be crucial for future human explorations of Mars.
The water frost was observed by two European Space Agency (ESA) spacecraft, first by the ExoMars Trace Gas Orbiter (TGO), which arrived at Mars in 2016, and then by the Mars Express mission, which will view the Red Planet from orbit explored the Earth. since 2003.
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The frost is located in the Tharsis region, the largest volcanic region on Mars, which is home to twelve major volcanoes. This includes Olympus Mons, which is not only the tallest volcano on Mars, but at 29.9 kilometers high it is also the highest peak in the solar system, making it about 2.5 times as high as Mount Everest, the highest mountain on Mars. Soil.
Adomas Valantinas made the discovery of “forbidden frost” on Mars as a PhD student at the University of Bern, Switzerland.
‘We thought it was impossible for frost to form around Mars’ equator because the mix of sunshine and a thin atmosphere keeps temperatures both on the surface and on the mountaintop relatively high – unlike what we see on Earth, where you would expect to see icy peaks,” Valantinas, now a postdoctoral researcher at Brown University, said in a statement. “Its existence here is exciting and indicates that there are exceptional processes at play that allow frost to form.”
The frost patches only appear for a few hours around sunrise and then evaporate as sunlight hits the Red Planet’s equator. The frost is also incredibly thin, with a thickness equivalent to that of a human hair (about one-hundredth of a millimeter) thick. Despite this, the frost patches cover a large area of each of the volcanoes, and their water contents could fill about 60 Olympic swimming pools, covering a surface area of almost 29.4 million gallons (111 million liters) of water.
This water constantly cycles between the surface and Martian atmosphere every day, taking about 24 and a half hours during the Red Planet’s cold seasons.
Mountain high, caldra deep
The Tharsis region is home to several massive volcanoes that tower over the plains of the Red Planet’s equator that surround them. Along with Olympus Mons, these peaks include the Tharsis Montes volcanoes known as Ascraeus, Arsia Mons and Pavonis, the latter of which is around the height of Mount Everest.
The frost was observed on the Tharsis volcanoes of Olympus, Arsia Ascraeus Mons and Ceraunius Tholus.
Each of these volcanoes contains deep cavities at their peaks, called “calderas”, which are created as magma chambers during eruptions. The team thinks that the strange way the air circulates above the Tharsis region generates a microclimate with the calderas that are unique from the broader climate in which the volcanoes are located. It is these microclimates that ensure that frost spots can form.
“Winds move along the slopes of mountains and bring relatively moist air from near the surface to higher altitudes, where it condenses and settles as frost,” said Nicolas Thomas, principal investigator of TGO’s Color and Stereo Surface Imaging System (CaSSIS), and said a researcher at the University of Bern said in a statement. “We actually see this happening on Earth and other parts of Mars, with the same phenomenon causing Mars’ seasonal Arsia Mons Elongated Cloud.”
Thomas added that the frost the team observed atop Martian volcanoes appears to settle in the shady areas of the calderas, especially in areas with colder temperatures.
Adomas explained that there are a few reasons why this frost on Mars’ equator went unnoticed until now.
‘First, we need an orbit that allows us to observe a location in the early morning. While ESA’s two Mars orbiters – Mars Express and TGO – have such orbits and can observe at any time of day, many from other organizations are instead synchronized with the satellite. sun and can only observe in the afternoon,” Adomas said. “Second, frost deposition is associated with colder seasons on Mars, making the chance of seeing it even lower.”
That means that in order to spot the short-lived frost, the team had to know exactly where and when to look for it, or they had to be extremely lucky.
“We happened to be looking for frost near the equator for another study, but didn’t expect to see it on the volcanic peaks of Mars!” Adamas added.
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“Finding water on the surface of Mars is always exciting, both for its scientific importance and for its implications for human and robotic exploration,” said Colin Wilson, ESA project scientist for both ExoMars TGO and Mars Express. “Yet this discovery is particularly fascinating.”
Wilson added that Mars’ low atmospheric pressure creates an unknown situation on the Red Planet, meaning the planet’s mountain peaks are usually no colder than the plains. Nevertheless, this study shows that moist air blowing up mountainsides can still condense into frost, something Thomas called a “decidedly Earth-like phenomenon.”
“This discovery was possible thanks to the successful collaboration between both ESA Mars orbiters and additional models,” Thomas concluded. “Understanding exactly which phenomena on Earth and Mars are the same or different will test and improve our understanding of fundamental processes taking place not only on our home planet, but also elsewhere in the cosmos.”
The team’s research was published Monday (June 10) in the journal Nature Geoscience.