One of the most mysterious discoveries made by the apparatus of the mission “New Horizons” on the farthest planet of the solar system was the “wind-and-sand” dunes on the edge of the giant glacier Sputnik Planitia. They look like terrestrial analogues, which the wind builds from the sand in the form of long, sinuous crests. There is no wind, no sand in the icy darkness of Pluto.
The atmosphere of the ninth planet is about 1000 times less dense than the earth’s, it is impossible to form a wind of such strength that it lifts the ground. And at a temperature of about -230 ° C, the surface of Pluto is covered mainly by frozen gases – methane, carbon monoxide, nitrogen. Conditions for the formation of dunes are not, and they are, and recently scientists finally figured out why.
The thing is in the extremely low gravity of Pluto, because of which the “symbolic” wind with speed of only 30-40 km / h can already move light particles of matter. These are the crystals of methane and nitrogen, which are formed during the transformation of ice into gas due to sublimation under the influence of solar radiation. Both the first and second phenomena are very rare, but only their combination allows the formation of alluvial structures similar to dunes. Therefore, by finding on the Planet Satellite, more than 500,000 years, for which they did not change at all.
“Every cosmic body in the solar system with its atmosphere and solid surface has its dunes, but everywhere their structure and mechanisms of education vary,” says Matt Telfer, a teacher of physical geography from the University of Plymouth. “The conditions on Pluto seem simply unrealistic for the appearance of dunes there, but now we have learned how they formed.”
