Another first from Pluto: frozen volcanoes in the distant solar system.

Recent detailed surface images from New Horizons show an interesting surface feature on Pluto. The mountain feature informally named Wright Mons is about 100 miles wide and 13,000 feet high. There are two interesting things about this feature. One is the deep depression on top that team members estimate to be about 35 miles across. The other is the distinctive rippled texture on its sides. It all suggests that Wright Mons, along with another feature called Piccard Mons, is a cryovolcano.

From New Horizons’ vantage point, these features looks just like volcanoes do on Earth when seen from orbit. But if they are cryovolcanoes, they’re doing something a little different. On Earth, volcanoes spew hot lava, volcanic ash, and gases from a subsurface magma chamber coating the surrounding land with a scorching hot layer of magma that eventually cools. A cryovolcano is different. Colloquially known as an ice volcano, these erupt with frozen volatiles. In the case of Pluto, it’s likely to erupt with a melted slurry containing water ice, frozen nitrogen, ammonia or methane.

Of course, New Horizons didn’t actually see any cryovolcanoes in mid-eruption, so this is just the team’s best guess on what these features are for the moment. If they are cryovolcanoes, the depression at the top would be from erupted material that collapsed, and the texture down the side would be from volcanic flows moving from the eruption site to the plains below.

It’s a compelling discovery. Cryovolcanism could provide an important clue in understanding Pluto’s geologic and atmospheric evolution.

Credit: NASA