Satellite of Pluto
Diameter 1,212 km
753 miles
Discovery date July 7, 1978
Discovered by James Christy

Charon is the largest satellite of the dwarf planet Pluto. It was discovered in 1978 at the United States Naval Observatory Flagstaff Station (NOFS).


Unlike Pluto's surface, which is composed mainly of nitrogen and methane ices, Charon's surface appears to be composed mainly of water ice. Observations made in 2007 showed patches of ammonia hydrates and water crystals on the surface of Charon that suggest the presence of active cryogeysers and cryovolcanoes.


The New Horizons spacecraft, to date the only probe to have visited the Pluto system, approached within 27,000 km (17,000 mi) of Charon.