Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Flybys of Jupiter ...

"Io represented a big mystery because its surface doesn't hold a record of its history the way that the surfaces of less active moons do." When you purchase through links on our site, we may earn an ...

Roughly 40 years ago, the Voyager 1 spacecraft sailed past one of Jupiter’s large moons, and it revealed something amazing: The rocky moon, called Io, is a volcanic champion, featuring the first ...

The most volcanic body in the solar system, Io is an infernal hellworld that constantly spits sulfurous magma into space. And a new study suggests that it’s been that way for a long, long time. The ...