# Eris

*In the Solar System*

The dwarf planet that cost Pluto its title: found in 2005, almost exactly Pluto's size and 27% more massive, which made it impossible to keep calling one of them a planet and not the other. It is currently about 96 AU out, three times Neptune's distance, on an orbit tilted 44° to everything else here. Its surface is nitrogen and methane ice, and its moon Dysnomia is what the mass was measured from.

| | |
| --- | --- |
| Radius | 1,163 km |
| Around the equator | 7,307 km |
| Mass | 1.64 x 10^22 kg |
| Compared with the Earth | 0.003 × |
| From the Sun | 14,281,232,297 km (-37,043 km/d) |
| From the Earth | 14,171,420,871 km (-1,687,811 km/d) |
| A signal takes | 13 h 8 m |

Distances and speed are computed from JPL Horizons trajectories and are true of 2026-09-05, changing at the rate given beside each. The interpolation itself is good to a few kilometres; what ages these figures is the date, not the arithmetic.

## Elsewhere

- On the live map: https://www.orbitalmap.space/?world=solar-system&focus=eris
- This object as a page: https://www.orbitalmap.space/o/eris/
- Every object: https://www.orbitalmap.space/o/
- What this site is and what it reads: https://www.orbitalmap.space/llms.txt