Moons · Moon of Jupiter

Callisto

778 million km from the Sun · Light crosses it in 0.016 seconds

Across
4,821 km
Vs Earth
0.38× Earth
Mass
1.8% of Earth

Open Callisto in Cosmic Scale

About

Callisto is the most heavily cratered object in the Solar System — a surface so old and so unchanged that it records four billion years of impacts. It orbits far enough out to sit mostly outside Jupiter's fierce radiation belts.

The most heavily cratered surface in the Solar System.

At a glance

OrbitsJupiter, every 16.7 days
Surface ageAbout 4 billion years
Valhalla basinRings out to 1,900 km
Discovered1610, Galileo

Did you know

  1. Its low radiation makes it the usual choice in studies of where a crewed base in the Jupiter system might go.
  2. It probably has a salty ocean 100 km or more beneath the surface.
  3. Unlike Io, Europa and Ganymede, it is not caught in the tidal resonance that heats them.

Real photo