Earth-like snow, ice features found on Pluto

Scientists have found evidence of Earth-like snow and ice features on Pluto, using a model similar to what meteorologists use to forecast weather on our planet and a computer simulation of the physics of evaporating ices.

"Penitentes" which are formed by erosion, are bowl-shaped depressions with spires around the edge, and are several metres high.

The groundbreaking research, done in collaboration with researchers at NASA and Johns Hopkins University, indicates that these icy features may exist on other planets where environmental conditions are similar.

"The identification of the ridges of Tartarus Dorsa as Penitentes suggests that the presence of an atmosphere is necessary for the formation of penitentes, which would explain why they have not previously been seen on other airless icy satellites or dwarf planets," said Professor John Moores, from York University in Canada.

"But exotic differences in the environment give rise to features with very different scales. This test of our terrestrial models for penitentes suggests that we may find these features elsewhere in the solar system, and in other solar systems, where the conditions are right," said Moores.

Moores and colleagues compared their model to ridges on Pluto imaged by the New Horizons spacecraft in 2015.

Pluto's ridges are much larger - 500 metres tall and separated by three to five kilometres - as compared to their meter-sized earthly counterparts.

"This gargantuan size is predicted by the same theory that explains the formation of these features on Earth," said Moores.

"In fact, we were able to match the size and separation, the direction of the ridges, as well as their age: three pieces of evidence that support our identification of these ridges as penitentes," he said.

Moores said though Pluto's environment is very different from the Earth - it is much colder, the air much thinner, the sun much dimmer and the snow and ice on the surface are made from methane and nitrogen instead of water - the same laws of nature apply.
The finding was published in the journal Nature.