In 2009 Pluto's catigorization was changed from 'Planet' to 'Dwarf Planet'.
- Mass: 1.303x1022kg /
0.002 Earths /
- Mean radius: 1'187km
- Satellites: 5
- Distance from sun: 4'437 to 7'311 Million km
- Orbital period: 248 years or 90'581 days
Official definition for the term "planet"
- The object must be in orbit around the Sun.
- The object must be massive enough to be rounded by its own gravity.
More specifically, its own gravity should pull it into a shape of hydrostatic equilibrium.
- It must have cleared the neighborhood around its orbit.
|Name||Diameter (km)||Discovery Date
|Nix||51 × 41 × 36||15/06/2005
|Hydra||55 × 40||15/06/2005
|Kerberos||12 × 4.5||28/06/2011
|Styx||7 x 5||26/06/2012