A simplified illustration of the parallax of an object against a distant background due to a perspective shift. When viewed from Viewpoint A, the object appears to be in front of the blue square. When the viewpoint is changed to Viewpoint B, the object appears to have moved in front of the red square.
From top to bottom: Io, Europa, Ganymede, Callisto. The Galilean moons are the four largest moons of JupiterâIo, Europa, Ganymede, and Callisto. They were discovered by Galileo Galilei around January 1610 and were the first group of objects found to orbit another planet. Their names derive from the lovers of Zeus.
Jupiter is the fifth planet from the sun, and has the most moons out of all the planets in our solar system. Some of the planets (Mercury and Venus) have no moons, while Jupiter has a whopping 63! These are just the known moons - so thereâs always a chance that more will be discovered! The four largest of Jupiterâs moons are known as the Galilean moons: Callisto, Europa, Ganymede, and Io. They were discovered by Galileo Galilei, an Italian astronomer, in 1610. Io is the closest moon to Jupiter, and is covered in many volcanoes.