🌙 Moon
Ganymede
The biggest moon in the solar system, bigger than Mercury.
- Size
- 5,300 km across, 41% as wide as Earth
- Goes round Jupiter
- every 7.2 Earth days
- Discovered
- 1610, by Galileo
Did you know?
- It is the only moon known to have its own magnetic field.
Compare Ganymede with EarthSide by side, to scale, in the app
More NASA photos of GanymedeStraight 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.