Charon, discovered by James Christy in 1978, is the largest satellite of Pluto. Its name reminds Caronte, a boatman from the Aqueront river. in Greek mythology, he was in charge of taking souls to hell. Its shape is spherical and is mainly formed by ice. It has the particularity of always showing the same face to Pluto and always seeing the same face of it while rotating both on its center of mass. For many years Charon was thought to be the only satellite orbiting Pluto, but as of 2005, 4 more have been discovered. Charon has a diameter of 1,208 km, just over half of Pluto, and both orbit at an average distance of 19,570 km around a barycenter. Charon's surface appears to be made of water ice.
