Named after their discoverer Galileo Galilei, the four moons which orbit around Jupiter are easily seen in binoculars and small telescopes.
The moons of Jupiter are some of the most fascinating things to observe in the night sky. The reason being is that they change their position from night to night and are relatively easy to see; a pair of 7×50 or 10×50 binoculars will show them well.
First recorded in 1610 by the Italian astronomer Galileo, the moons of Jupiter have proved to be an endless source of fascination for amateur and professional astronomers ever since. Jupiter, we now know, has dozens of moons orbiting around it, but the four largest are the only ones visible using ground-based amateur telescopes.
Among the most interesting things to observe with respect to these moons are the ways they move almost on an hourly basis. They can change their position from two moons each side of the planet to all being in a row on just one side as well as various other combinations. Even more interesting are the occultations and transits. An occultation is where the moons pass behind the planet, so for a short time being obscured to us here on Earth, whereas when they pass in front of the disc of Jupiter, it is known as a transit.