Io — Jupiter's fifth moon — is the most volcanically active body in the solar system. Io's surface is peppered with hundreds of volcanoes, some spewing sulfurous plumes hundreds of miles high.

Because Io is so close to its massive host planet, the moon is subjected to a tremendous gravitational pull as it orbits Jupiter once about every 42 hours, according to the Planetary Society.

Jupiter's volcanic moon Io doesn't appear to have a subsurface ocean of magma, resolving some issues about how Io's volcanoes erupt and raising broader questions about similar magma oceans within ...

Jupiter's moon Io is the solar system's most volcanic body thanks to a gravitational tug of war that rages below its surface. But now scientists know the violent moon has always been this way.

Jupiter moon of Io is famed for its volcanoes. NASA just spotted the most powerful one yet Not only was the hot spot larger than Earth’s Lake Superior, but it also was seen belching out ...

A NASA spacecraft made its closest-ever approach to Jupiter's moon Io, coming within 930 miles of the "surface of the most volcanic world," and the space agency released new images of the flyby ...

Jupiter's moon Io is a volcanic hellscape—and has been since the solar system began Io is the most volcanic body known to science, and researchers have puzzled over its history for years. A new ...

Recent flybys of the fiery world refute a leading theory of its inner structure—and reveal how little is understood about geologically active moons.

The spacecraft came to within 930 miles of Io's surface—the closest any spacecraft has flown by the Jovian moon in over 20 years.

Jupiter's moon Io, the most volcanic world in the solar system, was imaged from just 7,260 miles away.

On the fiery Io, the innermost and third-largest of Jupiter’s four Galilean moons, Juno's observations have provided more insights about its incessant volcanic activity.

On March 9, 1979, Linda Morabito discovered a volcanic plume on Io, a moon of Jupiter, in one of the photos from Voyager 1. She wrote, “I could feel tears begin to roll down my face at the sight ...