The mountains of Pluto are covered in snow, but not for...

In 2015, the New Horizons spacecraft discovered spectacular snow-capped mountains on Pluto that are strikingly similar to the mountains on Earth. Such a landscape had never been observed anywhere else in the solar system. However, when the atmospheric temperatures on our planet drop in altitude, they warm up on Pluto as a result of solar radiation at altitude.

Where does this ice cream come from? An international team led by CNRS scientists1 carried out this study. They first discovered that the “snow” on Pluto’s mountains actually consists of frozen methane, traces of this gas being present in Pluto’s atmosphere, just like water vapor on Earth. To understand how the same landscape can be created under such different conditions, they used a climate model for the dwarf planet that showed that Pluto’s atmosphere is rich in gaseous methane due to its special dynamics at high altitudes.

As a result, only at the tops of mountains high enough to reach this enriched zone does the air contain enough methane for it to condense. At lower altitudes, the air is too low in methane for ice to form. This research, published in Communication with naturecould also explain why the thick methane glaciers observed elsewhere on Pluto are dotted with spectacular, rugged ridges, as opposed to the flat glaciers on Earth, which are made of water.

More information:
The equatorial mountains on Pluto are covered in methane frosts resulting from a unique atmospheric process. Communication with nature (2020). DOI: 10.1038 / s41467-020-18845-3