Sedna is the outermost TNO in the Solar System orbiting a distance from the Sun 5 times further than Pluto and Eris.
| |
| Sedna | |
|---|---|
| Orbital characteristics | |
| Aphelion |
937 AU |
| Perihelion |
76.361 AU |
| Semi-major axis |
518.57 AU |
| Eccentricity |
0.8527 |
| Orbital |
11,400 years |
| Synodic period |
Unknown |
| Average orbital speed |
1.04 km/s |
| Mean anomaly |
358.01° |
| Inclination |
11.927° |
| Longitude of ascending node |
144.26° |
| Argument of perihelion |
311.02° |
| Satellites |
None |
| Physical characteristics | |
| Mean radius |
600 to 800 km |
| Flattening |
N/A |
| Surface area |
N/A |
| Mass |
1.8–4.3 x 1021 kg |
| Mean density |
2.0? g/cm3 |
| Equatorial surface gravity |
0.33 to 0.50 m/s2 |
| Escape velocity |
0.62 to 0.95 km/s |
| Sidereal rotation period |
10 hours |
| Equatorial rotation velocity |
Unknown |
| Axial tilt |
Unknown |
| North pole right ascension |
N/A |
| North pole declination |
N/A |
| Albedo |
0.16 to 0.30 |
| Surface temp. |
12 K |
| Apparent magnitude |
Unknown |
| Angular diameter |
N/A |
| Atmosphere | |
| Surface pressure |
Unknown |
| Compositions |
Unknown |
Orbit[]
Sedna is famous for it's eccentric orbit. It goes as close as 76 AU and as far as 718 AU. In 2114 it will overtake Eris as the farthest dwarf planet orbiting the Sun. Close-up, Sedna probably looks like a reddish version of Neptune's moon Triton.