Callisto
moon of Jupiter
5.36 AU from Earth
The most heavily cratered world in the Solar System, almost as wide as Mercury. Its dark, icy surface has barely changed in billions of years, and a salty ocean may lie deep beneath it.
- radius 2,410 km · 99% as wide as the planet Mercury
- Valhalla, its biggest impact, has rings 3,000 km across
Numbers that change with time are from 8 November 2026.
open Callisto in the atlas ›- kind
- place in the Solar System · moon or small world
- distance
- 0.01 AU from Jupiter
- size
- 4,820 km across
- orbits
- Jupiter