Mountain ridges and volcanic plains on Pluto’s moon, Charon.

Mountain ridges and volcanic plains create a rugged landscape on Pluto’s moon Charon. Credit: NASA

Planetary science

The forbidding terrain on Pluto’s biggest moon

Huge ridges and troughs on Charon hint at icy body's chilly past.

Pluto’s moon Charon features some of the most dramatic topography in the outer Solar System.

NASA’s New Horizons spacecraft flew past Pluto and Charon in 2015. Paul Schenk at the Lunar and Planetary Institute in Houston, Texas, and his colleagues analysed the resulting images and found that Charon’s highest point soars 19 kilometres above its lowest, one of the largest elevation ranges known on a medium-sized icy body.

Much of Charon’s surface is broken into enormous blocks tens to hundreds of kilometres across, separated by troughs as deep as 13 kilometres. These formations suggest that Charon’s surface has not experienced any recent heating events, which would have smoothed its rough terrain.

In a companion analysis of Pluto, Schenk and his colleagues found that the rim of a mountain called Piccard Mons is 11 kilometres higher than the mountain’s bowl-shaped central depression. That’s the largest elevation gap on Pluto.