| Charon |
| Pluto's only known satellite is Charon, therefore making it Pluto's only moon. It was named for the mythological figure who ferried those who died across the river of Acheron into the underworld, or Hades. Though it was officially named for the mythological meaning, it was also named in the honor of the discoverers wife, Charlene. The discoverer of Charon was Jim Christy, in 1978. Before the discovery of Charon, Pluto was thought to be much bigger because it blended with Pluto. Charon is very unusual because it is the largest moon in scale to its planet in the entire solar system. Some say that Pluto and Charon are two different planets, instead of a planet and its moon. The radius of the moon isn't well known, as well as the mass and density. There is more than two percent of a difference in measurnments from differnet places. The composition of Charon is unknown, but it has low density, much like Saturn's moons. It seems to be covered in ice water, and is very different than Pluto. Some say the moon was formed by a giant impact, much like the one that formed Earth's Moon. It is also doubtful that Charon has a significant atmosphere. Diameter: 1172 km Mass: 1.90e21 kg Orbit: 19,640 km from Pluto |