Saturn has 128 more moons than astronomers previously thought - The sixth planet from the Sun now has a grand total of 274 ...

While Galileo Galilei first observed Io in 1610 ... Io’s tidal response is a direct result of its proximity to Jupiter. The moon’s elliptical orbit causes varying gravitational forces to ...

Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo Galilei more than 400 years ago ...

Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – were the first ever discovered orbiting another planet. They were spotted by Galileo Galilei more than 400 years ago ...