Formations

As one of Earth’s most distant neighbours, the dwarf planet Pluto was only imaged in detail for the first time in 2015. This stunning image was taken by NASA’s New Horizons mission with a camera that enhanced the subtle colours to show Pluto’s complex features. Revealing mountains made of ice, frozen seas and even glaciers on this far-flung icy body, these images allowed scientists to suggest how these familiar yet exotic features formed

Mountain chains on Earth, such as the Andes of South America, form rocky spines that mark the collision of two tectonic plates, buckling the continent and thrusting rock upwards. Mountain scenes on Pluto, despite looking similar, are created by wildly different mechanisms. Pluto’s mountains are thought to be composed of water-ice, and while this is not unique in the solar system, only Pluto’s temperatures are cold enough to sustain ice with the strength to form mountains several kilometres high.

Scientists think Pluto’s mountains form when denser nitrogen ice fractures Pluto’s icy crust, a process not seen anywhere on Earth. Even the snowy caps of these mountains hide a surprise: they are made of methane.