Charon (moon) but they are not large enough to be spherical, and they are simply considered to be satellites of Pluto (or of Pluto–Charon). Charon (moon) Charon, also known as (134340) Pluto I, is the largest of the five known natural satellites of the dwarf planet Pluto. It has a mean radius of 606 km. It was discovered in 1978 at the United States Naval Observatory in Washington, D.C., using photographic plates taken at the United States Naval Observatory Flagstaff Station (NOFS). With half the diameter and one eighth the mass of Pluto, Charon is a very large moon in comparison to
Timeline of United States discoveries alcohol 2003 Sedna 2003 Psamathe 2003 Mab 2003 Perdita 2003 Cupid 2004 Orcus 2005 Makemake 2005 Eris Eris, formal designation 136199 Eris, is the largest-known dwarf planet in the Solar System and the ninth-largest body known to orbit the Sun directly. It is approximately 2,500 kilometres in diameter and 27% more massive than the dwarf planet Pluto. Eris was discovered in 2005 at W. M. Keck Observatory by American astronomer Michael E. Brown. 2005 Dysnomia Dysnomia, officially (136199) Eris I Dysnomia, is the only known moon of the dwarf planet Eris. In conjunction of finding Eris, American astronomer Michael E.