Cosmic Scale
Sedna
Distant dwarf planet · About 83 AU from the Sun
How big is Sedna?
Sedna is about 1,000 km across.
See Sedna in 3D, at true scale
Sedna is one of the most distant known worlds in the Solar System. Its stretched orbit never brings it closer than 76 AU from the Sun and carries it out to about 900 AU, so a single trip around takes some 11,000 years.
At a glance
| Diameter | 1,000 km |
|---|---|
| Diameter compared with Earth | 0.079 × Earth |
| Size | About 1,000 km |
| Orbit | About 11,000 years |
| Closest to the Sun | 76 AU, in 2076 |
| Discovered | 2003 |
Good to know
- It is one of the reddest objects in the Solar System, coloured by sunlight-cooked ices.
- Nothing known could have pushed it onto its orbit, which is one reason people suspect a distant unseen planet or a passing star.
- It is named after the Inuit goddess of the sea.