FANDOM


Io
Io-moon
Description
Satellite of Jupiter
Orbital period 42 hours
Diameter: 3,643 km
Radius: 1,822 km
Discovered January 8, 1610
Discoverer(s) Galileo Galilei

Io is the innermost of the four Galilean moons of the planet Jupiter. It is the fourth-largest moon, has the highest density of all the moons, and has the least amount of water of any known astronomical object in the Solar System.