🌙 Moon
Callisto
The most heavily cratered world in the solar system.
- Size
- 4,800 km across, 38% as wide as Earth
- Goes round Jupiter
- every 16.7 Earth days
- Discovered
- 1610, by Galileo
Did you know?
- It is almost as wide as the planet Mercury.
- Its surface is one of the oldest in the solar system, covered in craters from billions of years of impacts.
Photographed or visited by
Galileo
Fourteen years at Jupiter, and a probe dropped into its clouds.
Compare Callisto with EarthSide by side, to scale, in the app
More NASA photos of CallistoStraight from NASA’s image library, in the app
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All of solar system
Mercury
The smallest planet, and the closest to the Sun.
Venus
The hottest planet, hidden under thick clouds.
Earth
Our home, the only world known to have life.
Mars
The red planet, with the tallest volcano in the solar system.
Jupiter
The biggest planet, with a storm larger than Earth.
Saturn
The ringed giant, light enough to float in water.