A waxing Moon brightens the sky as we catch our last looks at Uranus and view Venus, Mercury, Jupiter, and Mars in the sky ...

Ganymede, Jupiter's largest moon and the solar system's largest, is bigger than Mercury and the dwarf planet Pluto, with a diameter of 5,268 kilometers.

Fluorescent cave minerals are helping scientists explore how life could survive in harsh places like Europa. Far beneath ...

But it hasn’t always been this way. Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo ...

Io is an incredibly active and extreme place, with glistening lava lakes and volcanic eruptions shooting sulfur and magma to huge heights.

Fluorescent caves deep below America show how alien life could exist on one of Jupiter's moons, say scientists. The chemistry ...

1:42 P.M. Today starts a run of events taking place around mighty Jupiter, as its Galilean moons show off while they dance in their orbits around the gas giant. Tonight, Europa and Ganymede ...

Jupiter's second-largest moon has more impact craters on its surface than any other planetary body in the solar system, and it has tons of ice on its surface as well. For decades. researchers ...

(Earth's Moon is 2,159 miles across, while Jupiter's largest moon, Ganymede, measures 3,270 miles.) They're also considered irregular, meaning their orbits are variably inclined, eccentric (oval ...