Dwarf planet
Eris
A distant dwarf planet almost exactly the size of Pluto. Its discovery in 2005 forced astronomers to define what a planet is.
| Diameter | 2,326 km |
|---|---|
| Mean distance from the Sun | 67.900 AU (10,158 mln km) |
| Rotation period | 15.8 days |
| Orbital period | 558.1 year |
| Known moons (2025) | 1 |
| Naked-eye visible | No |