NASA’s Dawn spacecraft arrived at the dwarf planet Ceres in March of last year, and what it found there was rather unexpected. Scientists had always expected Ceres to be a lifeless chunk of rock, the furthest possible thing from geologically active. And yet, there are some interesting things going on across Ceres, including a cryovolcano half the size of Mount Everest on Earth.The NASA team detected the mountain, now known as Ahuna Mons, near the equator of the dwarf planet. At first, they weren’t sure how to classify this feature. It had the same basic shape as a volcano on Earth from the dome to the steep flanks surrounding it. The formation is also much younger than the surrounding terrain, as evidenced by the sharp lines and relative lack of craters. Of course, Ceres doesn’t have enough internal heat for volcanic activity. A cryovolcano was the only possible explanation.This isn’t the first time Ceres has surprised scientists. It was discovered in 1801 and thought to be a planet, but that was before we knew that asteroids existed. It was demoted to an asteroid a few decades later, though a huge one. Then, in 2006 it was promoted to a dwarf planet along with Pluto.With a more geologically active surface, Ceres is looking more planet-like. It is believed that Ahuna Mons has spewed salt water into space within the last billion years. The water freezes and falls back down to cover the cryovolcano in an icy dome. This was happening quite recently for what was believed to be a static ball of rock and ice.At three miles tall and twelve miles wide, Ahuna Mons stands out on a dwarf planet the size of Texas. NASA plans to make a series of mapping runs across Ahuna Mons to get a better idea of its mineral composition. The hope is Dawn can find something unique about that area of Ceres that could explain the formation of such a giant cryovolcano.