Two icy moons of Jupiter, though neighboring and of similar size, exhibit radically different internal structures. A new study suggests this dichotomy stems from their very formation, ...

Jupiter is the largest planet in our solar system with 80 moons. Galileo was the first to discover the moons of Jupiter on this day in history, Jan. 7, 1610.

On this date, Jan. 7, 1610, astronomer Galileo Galilei, with a homemade telescope, noticed three points of light near Jupiter ...

Recent flybys of the fiery world refute a leading theory of its inner structure—and reveal how little is understood about ...

Jupiter’s four largest and most well-studied moons were first discovered more than 400 years ago. And they still make for wonderful observational targets.

The first astronomer to discover moons around Jupiter was Galileo, back in the year 1610, but astronomers are still finding more and more moons around this gas giant.

On this date, Jan. 17, 2002, the Galileo probe made it’s 33 rd pass of Jupiter’s moon, Io.. After Voyager 1’s pass in 1979, Io was dubbed the most volcanically active place in the solar system.

As ruler of the skies, Jupiter absolutely reigns supreme as the giant of our solar system. It has a mass 318 times that of Earth’s, a volume 1,321 times larger, and a surface area 120 times greater.

The four "Galilean moons" were named after Italian astronomer Galileo Galilei, who is thought to have discovered them in 1610. As night falls, Jupiter will rise in the east-northeast, ...

On November 5, 2002, NASA's old Galileo spacecraft was almost out of fuel. But the Jupiter mission still had some science to do. ‘On This Day in Space’ Video Series on Space.com Galileo flew ...