Dwarf Planet
Sedna
The most distant large body known in the Solar System: even its perihelion of 76 AU lies beyond the Kuiper Belt, and its aphelion is ~900 AU. With an ~11,400-year orbit and a surface as red as Mars, it is regarded as the first member of the inner Oort Cloud; it reaches perihelion in 2076.
| Type | Dwarf Planet |
|---|---|
| Parent body | Sun |
| Radius | 500 km · 0.0785 R⊕ |
| Mass | 1.000 × 10²¹ kg · 1.67 × 10⁻⁴ M⊕ |
| Mean density | 1.91 g/cm³ |
| Surface gravity | 0.267 m/s² · 0.027 × Earth |
| Escape velocity | 0.517 km/s |
| Rotation period | 10.3 hours |
| Orbital radius | 506 AU (Sun) |
| Eccentricity | 0.850 |
| Orbital period | 11,400 years |
| Discovery | 2003, Brown, Trujillo, Rabinowitz |
| Perihelion | 76 AU (2076) |
| Orbital period | ≈ 11,400 years |