A recent paper led by Matthew Telfer, a lecturer in physical geography at the University of Plymouth, reveals a quite intriguing discovery on the dwarf planet Pluto. Methane ice dunes have been observed at the bottom of a major mountain range on the planet, in the Sputnik Planitia region, Pluto’s heart-shaped plain. A landscape that looks familiar to us was unveiled through detailed images from the New Horizons probe. Wind-blown ice or sand dunes are also found on Earth, as well as on Mars, Titan, Venus and even on comet 67P, even though it lacks a substantial atmosphere.
An international team of researchers analyzed the surface of the planet based on the images that have been taken by the NASA spacecraft. It has been observed that these dunes could be composed of sand-sized grains of solid methane ice carried through the regular winds from Pluto.
At an average temperature of -230°C, the freezing planet’s surface is mostly covered with solid forms of methane, carbon monoxide and nitrogen. Also, Pluto’s atmosphere is 100,000 times thinner than ours, so it might come as a surprise that dune-like landforms could be found there. Matthew Telfer said in a statement that “It turns out that even though there is so little atmosphere, and the surface temperature is around -230C, we still get dunes forming.”
After observing the size and the shape of the dunes and judging by the wind streaks on the planet’s surface, scientists came to the conclusion that sand-sized grains of methane were most likely released into the atmosphere from solid nitrogen, through the process of sublimation. Afterwards, these tiny grains must have been blown by the winds until they settled at the bottom of the mountain range.
Such discovery was quite surprising, due to the weak atmosphere of Pluto, but through the data that scientists gathered, we should be able to gain more insight into how this small planet is influenced by geological processes. Understanding the formation of dunes on Pluto, while taking the planet’s conditions into account, will help researchers make sense of similar features found elsewhere in the solar system.