Pluto has established itself as a diverse, dynamic and exciting world, packed with strange phenomena with which planetary scientists constantly have problems when trying to explain them. And now they have discovered the ice oddity, which highlights one of the key processes by which this surprisingly young surface of a dwarf planet is believed to have formed.
Recently, high-expansion images sent to Earth from NASA's New Horizons mission, which caught the buzz of Pluto on July 14, 2015, make it clear that a piece of ice has been ripped off Pluto's surface. Upper layers of methane are absent in the western plain called Piri Plain, the peculiarity of which is that it is enriched with water ice.
Further from the Piri Plain is a very old terrain with craters called Vega Terra, separated from the young plain by rocks (or “ledges”). Some of them seem to have broken off, creating isolated hills (or “table mountains”). But what led to this gap? Why was the surface rich in methane ice layers cut off from the rocks, giving way to a lowland plain with water ice?
According to scientists, the answer probably lies in how different types of ice react under extreme conditions when heated.
As we can probably assume, Pluto is a cold place. Although this icing is far from a static state. Chemicals that are usually on Earth in a gas or liquid state on Pluto are transformed into solid layers of ice. When the world receives even the smallest portions of heat, volatile substances — such as methane or ammonia ice — sublimate.
Sublimation occurs at atmospheric pressure or at low temperature (or both of these options). Ice water, for example, when the sea level pressure on Earth turns into a liquid, and then transforms into vapor (or gas) when heated. On Pluto, because of the cold and the pressure of the vacuum level, water in the liquid state does not occur at all, and the heated ice immediately sublimates from solid to gaseous. And it turns out that this is what happens with methane ice in the Piri Plain. Everything is explained by the process of sublimation in the thin atmosphere of the planet, which probably contributes to the atmospheric cycles of the surface ice of the dwarf planet.
This is comparable to the fact if Pluto received a rejuvenating facial scrub. For millions of years, its surface is slightly heated from our distant sun, and surface ice during sublimation creates new promising regions, free from ancient craters.