Io, one of the four Galilean moons of Jupiter, as seen by the Galileo probe, 1997. Two volcanic eruptions are visible, one at the top, from the Pillan Patera, and the Prometheus plume at the ...

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 ...

The Galilean moon Io has already lost sextillions of tons of sulfur, and will someday run out of this element. ... Jupiter’s moon Io has likely been active for our solar system’s entire history.

Because Io is so close to its massive host planet, the moon is subjected to a tremendous gravitational pull as it orbits ...

Io orbits closest to Jupiter, out of the four Galilean moons. Io has been studied by spacecraft from Pioneer 10 and 11 in 1973 and 1974, all the way up to New Horizons in 2007, augmented by Earth ...

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 ...

As the innermost of Jupiter’s four Galilean moons, Io is stuck between the planet’s immense gravitational force and the gravitational tug of its sister moons Europa and Ganymede.

If you look at the gas giant with a telescope as it’s rising, you’ll spot three of its Galilean moons: Io alone to the west, with Ganymede (closer) and Callisto (farther) to the east.

Io, one of the four Galilean moons of Jupiter, as seen by the Galileo probe, circa 1997. Space Frontiers/Hulton Archive/Getty Images. Io is the solar system's most volcanically active world.

In the latest of more than 50 flybys, NASA's Juno spacecraft is slated to pass Jupiter's volcanic moon Io on Tuesday. The agency said this will be the closest flyby to date.

Hay and his colleagues modeled the gravitational interactions among Jupiter's four large Galilean moons — Io, Europa, Callisto and Ganymede.The latter three are thought to harbor huge oceans of ...

The second-smallest of the four large so-called Galilean Moons—the others being Ganymede, Europa and Callisto—Io is the most volcanic world in the solar system.