Io

Io (Jupiter I) is a moon of Jupiter, discovered by Galileo Galilei in 1610. It orbits Jupiter every 42 hours and shines at about magnitude 5.0.

The most volcanic world known. It circles Jupiter in 42 hours, so its place changes visibly in an evening.

Other moons of Jupiter: Europa, Ganymede, Callisto.

Open AstroPilot to see where Io is next to Jupiter tonight and how easy it is with your telescope.