7 Things We've Learnt About Pluto Since New Horizons

3. It Has Frozen Volcanoes

New Horizons recently beamed back some detailed photos of something that seems to belong in the world of sci-fi: Cold volcanoes. These cryovolcanoes are the first of their kind to be discovered in the solar system. They work exactly like a volcano here on Earth, except that, instead of spewing out hot, molten lava, the cryovolcanoes erupt with a volatile slush of water ice, frozen nitrogen, ammonia and methane. These things are huge too, reaching over three miles high, 100 miles wide and with a depression in the middle spanning 35 miles. Although we didn't catch them erupting, it sounds like it would be pretty spectacular if it did. As the Earth's volcanoes are powered by the molten magma in its hot mantle, the presence of these ice volcanoes might indicate some kind of subterranean ocean of water or liquid nitrogen beneath the surface of Pluto.