1. Jupiter’s moon lo is the innermost of the four Galilean moons of Jupiter and the fourth-largest moon in our Solar System.
2. lo is approximately 3,630 km (2,556 miles) across, slightly bigger than our own Moon.
3. It is the only known place in the Solar System with volcanoes erupting hot lava like that on our planet.
4. Io has more than 400 active volcanoes, which are caused by tidal heating.
5. Io has a thin atmosphere that can teach us about the exotic moon’s volcanic activity.
6. NASA’s Juno spacecraft spotted stunning images of the lunar surface - a mountain and an island amidst a lava lake.