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.
Additionally, Saturnâs moons were discovered over a period of time. Christian Huygen discovered Titan, which is Saturnâs largest moon. Giovanni Domenico Cassini discovered four moons â Iapetus, Rhea, Tethys, and Dione. In 1789, the astronomer William Herschel discovered two more moons â Mimas and Enceladus. In 1848, British scientists discovered a moon called Hyperion.