🌙 Moon
Io
The most volcanic world in the solar system.
- Size
- 3,600 km across, 29% as wide as Earth
- Goes round Jupiter
- every 42.5 hours
- Discovered
- 1610, by Galileo
Did you know?
- It has hundreds of volcanoes, some shooting lava fountains dozens of kilometres high.
Photographed or visited by
Galileo
Fourteen years at Jupiter, and a probe dropped into its clouds.
Compare Io with EarthSide by side, to scale, in the app
More NASA photos of IoStraight 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.