In Depth | Europa – NASA Solar System Exploration
Jupiter’s moons Io, Europa, and Ganymede are in what is called a resonance – every time Ganymede orbits Jupiter once, Europa orbits twice, and Io orbits four times.
In Depth | Ganymede – NASA Solar System Exploration
Jupiter’s moon Ganymede is proving to be a fascinating world. Not only is it the largest moon in our solar system, bigger than the planet Mercury and the dwarf planet Pluto, but NASA’s …
In Depth | Jupiter Moons – NASA Solar System Exploration
NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
In Depth | Moons – NASA Solar System Exploration
Jupiter's menagerie of moons includes the largest in the solar system (Ganymede), an ocean moon (Europa) and a volcanic moon (Io). Many of Jupiter's outer moons have highly elliptical …
Callisto - NASA Solar System Exploration
Jun 26, 2019 · Galileo spotted what he thought were bright stars near Jupiter, but eventually figured out that the “stars” were moons orbiting Jupiter. The German astronomer Simon …
Jupiter - NASA Solar System Exploration
4 days ago · Jupiter has 95 moons that have been officially recognized by the International Astronomical Union. But the number doesn't capture the complexity of the Jovian system of …
In Depth | Callisto – NASA Solar System Exploration
Jupiter and its moons orbit about 484 million miles (778 million kilometers) from our Sun. It takes the Jovian system—Jupiter and all of its moons—about 12 Earth years to complete one orbit …
In Depth | Io – NASA Solar System Exploration
Jupiter's rocky moon Io is the most volcanically active world in the solar system, with hundreds of volcanoes, some erupting lava fountains dozens of miles (or kilometers) high.
Planet Compare - NASA Solar System Exploration
Oct 21, 2025 · NASA’s real-time science encyclopedia of deep space exploration. Our scientists and far-ranging robots explore the wild frontiers of our solar system.
Europa By the Numbers – NASA Solar System Exploration
Oct 21, 2025 · Europa is one of the largest of Jupiter’s more than 90 moons. It's the sixth-closest moon to the planet.