New analysis of images from the New Horizons probe has revealed that the luminous, icy surface of Pluto's Satellite Plane is formed by multiple active cryovolcanoes.
In 2015, the New Horizons space probe visited Pluto for the first time and examined it up close. Among other finds on the dwarf planet's surface, cryovolcanoes were discovered. Similar to Earth's volcanoes, in the extreme cold they spew not molten rock but a liquid mixture of light substances such as water and ammonia.
Cryovolcanism exists on some satellites of Saturn and Jupiter, on the largest body in the asteroid belt, Ceres, and, apparently, on Pluto. Moreover, cryovolcanoes dwarf planet quite numerous, active and play a prominent role in the formation of its surface. This is the conclusion reached by the authors of a new paper published in the journal Nature Communications.
"Not erosion or any other geological process, but it is cryovolcanic activity that brings large amounts of material to Pluto's surface, forming an entire region that New Horizons has studied at close range," said Kelsi Singer of the American Southwestern University in Boulder, one of the authors of the new paper.
We are talking about the Plutonian Plain of Sputnik, part of the Tombo Area, famous for its heart-like shape. Its left half, bright and smooth, is the Plain of Sputnik. Several large cones have been discovered there, reaching heights of up to seven kilometres and diameters of up to 100 kilometres.
The nature of these structures of the Sputnik Plain remains uncertain. However, after studying New Horizons images, astronomers have concluded that the ice-bound surface and the peaks on it are formed by cryovolcanism. The erupted material covers an area of at least 300 by 600 kilometres, which shows no sign of impact craters. They have apparently all been 'wiped out' by the high activity of the local volcanoes.
Such activity requires a large quantity of liquid water in the bowels of the dwarf planet, and hence the operation of some internal mechanism that could heat it up. It is possible that the matter underlying the plain of Sputnik somehow retains residual heat from the early stages of Pluto's existence. Only the liquid brought to the surface freezes in the extreme cold, despite the presence of ammonia and other impurities that lower the melting point of water.