Moons · Moon of Jupiter
Io
778 million km from the Sun · Light crosses it in 0.012 seconds
- Across
- 3,643 km
- Vs Earth
- 0.29× Earth
- Mass
- 1.5% of Earth
About
Io is squeezed between Jupiter's gravity and the pull of the other large moons, and the friction melts its insides. The result is the most volcanically active world known: hundreds of erupting volcanoes, lava lakes, and plumes that rise hundreds of kilometres.
The most volcanic world known, with over 400 active volcanoes.
At a glance
| Orbits | Jupiter, every 1.8 days |
|---|---|
| Volcanoes | 400+ active |
| Surface flex | Up to 100 m of tides |
| Discovered | 1610, Galileo |
Did you know
- Its surface is repaved so fast that it has essentially no impact craters.
- The yellows, oranges and whites are sulfur and sulfur dioxide frost.
- Loki Patera, a lava lake 200 km wide, brightens on a roughly 500-day cycle.
Real photo
- Io in true colour, from Galileo — NASA/JPL/University of Arizona · source