Io
The most volcanically active body in the solar system and innermost Galilean moon.
About
Io is the innermost and third-largest of Jupiter's four Galilean moons. It is the most volcanically active body in the solar system, with over 400 active volcanoes driven by tidal heating from Jupiter's immense gravity. Its surface is covered in sulfur and sulfur dioxide frost.
Properties
Notable Facts
Io has over 400 active volcanoes, making it the most volcanically active body in the solar system
Tidal heating from Jupiter generates enormous internal heat
Its surface is constantly being reshaped by volcanic activity, with no impact craters visible
Io's volcanoes can eject plumes of sulfur up to 500 km above the surface
Other Moons of Jupiter
Europa
Jupiter moon with a subsurface ocean considered a prime candidate for extraterrestrial life.
3,121.6 km
Diameter
3.6 d
Orbit
1610
Discovered
Ganymede
The largest moon in the solar system, bigger than Mercury, with its own magnetic field.
5,268.2 km
Diameter
7.2 d
Orbit
1610
Discovered
Callisto
Jupiter's second-largest moon with the most cratered surface in the solar system.
4,820.6 km
Diameter
16.7 d
Orbit
1610
Discovered