Satellite weather maps on Mars have shown that millions of "dust devils" appear on its surface every day, small sandstorms, whose number was underestimated by scientists dozens of times, according to an article accepted for publication in the Icarus journal.
“Dust on Mars plays the same role as water in the Earth's atmosphere - it is the main 'conductor' of Martian weather. Understanding how this dust lifts into the air is key to understanding the weather processes on Mars, and without it we simply cannot understand how the various atmospheric processes on the red planet work,”explains Mark Lemmon, an astronomer at Texas Tech. University of A&M at College Station (USA), quoted by New Scientist.
On Mars, unlike Earth, the main driving force of all climatic processes and the cause of soil and rock erosion are not rains, seas and rivers, but winds, air currents and dust storms. The first high-quality images of Mars taken by NASA in 1985 after the arrival of the Viking probe showed that such storms are incredibly frequent on the red planet, and that they can pose a great threat to future travelers and colonists.
In addition to large storms, on the surface of Mars, as shown by the mysterious dark lines on the surface of some dunes and craters, small hurricanes, the so-called "dust devils", often occur, with a diameter of about 100 meters and lasting several minutes. Due to their small size, they are almost impossible to see from orbit, which interferes with estimates of how often they occur and what kind of threat they can pose to Marsonauts.
Brian Jackson from Boise State University (USA) and his colleagues were able to count the number of such "dust devils" and estimate how much dust they emit the atmosphere, drawing attention to how they affect the local climate in different parts of Mars.
As scientists explain, the appearance or passage of the "dust devil" over this or that part of the planet's surface leads to the fact that atmospheric pressure drops sharply, and the speed and direction of the winds over this area change noticeably.
These changes, in turn, are reflected in weather and climate, which allows observations of fluctuations in pressure and wind patterns to be used to estimate the number of eddies on the surface of Mars.
Guided by these ideas, Jackson and his colleagues analyzed images of the surface taken by the MGS probe and its "successors", as well as measurements of barometers and other climatic scientific instruments installed on the Phoenix lander and on the Curiosity rover.
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As shown by these calculations, dust vortices appear on the surface of Mars about 10 times more often than scientists previously thought. Every day, according to Jackson and his colleagues, several million "dust devils" can simultaneously exist on Mars, whose diameter is about 10-20 meters, and not 100 meters, as previously thought. In fact, there must be at least one "devil" on every square kilometer of Mars' surface.
A large number of such vortices, according to Jackson, could pose a great danger to future expeditions to Mars, since the friction of dust particles in the dry air of Mars will generate powerful electric fields that can damage the electronics of the descent vehicles, spacesuits and other gadgets.
