Aster › Space program › Sedna
Sedna
Position on the route: 33/45 · level needed 540 · journey (Mk0 engine) 142.7 h
By the numbers
| Diameter | ≈ 1,000 km |
|---|---|
| Orbit | 11,400 years |
| Distance from the Sun | 76–937 AU |
| Colour | very red |
The story
When found in 2003 it was the most distant known object of the Solar System: 76 AU at perihelion, 937 AU at aphelion. It is named for the Inuit goddess of the sea because it lives in such a cold and dark place. Its surface is redder even than Mars.
Its orbit is so long that Neptune’s gravity cannot explain it. That gave rise to the idea that it was shaped by a passing star or by a still-undiscovered ‘Planet Nine’.
Missions
- No mission so far; it will be nearest to the Sun (perihelion) in 2076
Colony note
A rock-and-ice world on the edge of the inner Oort Cloud: the farthest outpost of the Solar System.
What probes bring back
- Its orbit takes 11,400 years, 76–937 AU from the Sun: among the most distant known large bodies.
- It is very red; its orbit may be the trace of a passing star or of a ninth planet.