In Depth | Europa – NASA Solar System Exploration
Formation 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, …
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 | Asteroids – NASA Solar System Exploration
Early in the history of the solar system, the gravity of newly formed Jupiter brought an end to the formation of planetary bodies in this region and caused the small bodies to collide with one another, …
In Depth | Amalthea – NASA Solar System Exploration
Amalthea and Thebe rotate on their axes once for each orbit around Jupiter, always keeping the same side facing the planet. This orbit takes about one-half an Earth day for Amalthea and two-thirds an …
In Depth | Io – NASA Solar System Exploration
The composition of this material is not yet entirely clear, but theories suggest that it is largely molten sulfur and its compounds (which would account for the varied coloring) or silicate rock (which would …
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.
In Depth | Titan – NASA Solar System Exploration
Vast regions of dark dunes stretch across Titan’s landscape, primarily around the equatorial regions. The "sand" in these dunes is composed of dark hydrocarbon grains thought to look something like …
In Depth | Sun – 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 | 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 …