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 | Callisto – NASA Solar System Exploration
That finding put the once seemingly dead moon on the list of worlds that could possibly harbor life. Callisto was discovered Jan. 7, 1610, by Italian scientist Galileo Galilei along with Jupiter’s …
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 …
In Depth | Io – NASA Solar System Exploration
Although Io always points the same side toward Jupiter in its orbit around the giant planet, the large moons Europa and Ganymede perturb Io's orbit into an irregularly elliptical one.
Jupiter - NASA Solar System Exploration
Sep 3, 2025 · The giant planet has thousands of small objects in its orbit. This composite image shows the edge of Jupiter, and Jupiter's four largest moons. From top to bottom, the moons …
In Depth | Amalthea – NASA Solar System Exploration
Orbiting within Io's orbit, which is the innermost of the four largest moons of Jupiter (called the Galilean moons), are four smaller moons named Metis, Adrastea, Amalthea, and Thebe.
In Depth | Titan – NASA Solar System Exploration
Titan is bigger than Earth's moon, and larger than even the planet Mercury. This mammoth moon is the only moon in the solar system with a dense atmosphere, and it’s the only world besides …
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.
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.
In Depth | Our Solar System – NASA Solar System Exploration
The giant planets Jupiter and Saturn lead our solar system’s moon counts. In some ways, the swarms of moons around these worlds resemble mini versions of our solar system.