as its Galilean moons show off while they dance in their orbits around the gas giant. Tonight, Europa and Ganymede transit Jupiter together, as they have a few other times this month. However ...

Following the discovery of the Galilean moons in January 1610 by means of a ... in California – the largest telescope in the world at the time. The moon, discovered by Barnard, orbits Jupiter within ...

A report by the New York Times said these moons were possibly formed by “cosmic smashups” that sent debris into Saturn’s orbit about 100 million years ago. “Many of these moons are rocks ...