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 Hubble Space …
In Depth | Titan – NASA Solar System Exploration
This mammoth moon is the only moon in the solar system with a dense atmosphere, and it’s the only world besides Earth that has standing bodies of liquid, including rivers, lakes and seas, on its surface.
Callisto - NASA Solar System Exploration
Jun 26, 2019 · Italian astronomer Galileo Galilei discovered Callisto and Jupiter’s other three large moons: Ganymede, Io and Europa. The discovery led to the understanding that planets in our solar …
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 orbits and …
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.
In Depth | Callisto – NASA Solar System Exploration
Callisto was discovered Jan. 7, 1610, by Italian scientist Galileo Galilei along with Jupiter’s three other largest moons: Ganymede, Europa and Io. Callisto is named for a woman turned into a bear by Zeus …
Galleries | Callisto – NASA Solar System Exploration
Oct 21, 2025 · This composite image includes Jupiter with its Great Red Spot. and from top to bottom: Io, Europa, Ganymede, and Callisto.
In Depth | Europa – NASA Solar System Exploration
Jupiter’s large Galilean moons – Io, Europa, Ganymede, and Callisto – likely formed out of leftover material after Jupiter condensed from the initial cloud of gas and dust surrounding the sun, early in …
Ganymede 3D Model – NASA Solar System Exploration
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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.