Analysis of data and images collected by the New Horizons mission has revealed surface structures that appear to have been produced by a phenomenon known as cryovolcanism, of a type and scale unheard of elsewhere in the world. Solar system.
Strange domes of ice
In 2015, the probe New Horizons from NASA was flying over Pluto, giving us an unprecedented glimpse of the distant dwarf planet. Years later, the data gleaned continues to shed new light on this frozen world, as shown in this new study, led by scientists from Southwest Research Institute and published in the journal Nature Communications.
Measuring between 1 and 7 kilometers high and 30 to 100 wide, the strange domes described by the researchers were discovered in an area located south-west of the famous plain Sputnik. It seems that several of them merged to form the most imposing structures, presenting an irregular relief characterized by the alternation of hills, mounds and depressions.
According to the team, this type of geology bears an uncanny resemblance to that produced by the cryovolcanisme, a phenomenon very similar to classical volcanism where sticky liquids composed of ice, water and ammonia replace hot, molten rocks. Although it has already been observed on other cold bodies in the Solar System, such as Enceladethe moon of Saturnand the dwarf planet Ceresand that it had long been suspected of occurring on Plutothis new research provides additional evidence.
« The particular structures we have studied are unique to Pluto, at least so far “, Explain Kelsi Singer, lead author of the study. ” Rather than erosion or other geological processes, cryovolcanic activity appears to have emitted large amounts of material to the surface, having reshaped an entire region of the hemisphere that New Horizons has been able to observe up close. »
Discoveries raising new questions
The fact that the area is almost completely free of craters suggests that it is geologically relatively young. But that only raises new questions.
Since cryovolcanism involves a minimum amount of heat (allowing matter to be kept in a viscous state), it is probable that Pluto’s entrails received more of it in the past, or that they were able to keep it much longer than expected.
« One of the benefits of exploring new places within the Solar System is that we find things we didn’t expect. “, valued Singer. « These bizarre-looking giant cryovolcanoes observed by New Horizons are helping to expand our knowledge of volcanic processes and geological activity in icy worlds. »
