Title:[0319] Jupiter and its Galilean satellites Caption:Jupiter and its four planet-sized moons, called the Galilean satellites, were photographed in early March 1979 by Voyager 1 and assembled into this collage. They are not to scale but are in their relative positions. Reddish Io (upper left) is nearest Jupiter; then Europa (center); Ganymede and Callisto (lower right). Twelve other smaller satellites circle Jupiter, four inside Io's orbit and the others millions of miles from the planet. Not visible is Jupiter's faint ring of particles, seen for the first time by Voyager 1. Copyright: Credit:NASA

Title:[0437] Jupiter, Io and Europa Caption:Io (reddish, over Great Red Spot) and Europa seen crossing in front of Jupiter in a Voyager 1 image of Jupiter taken on 13 January 1979. Copyright: Credit:A NASA/JPL PHOTO

Title:[0350] Jupiter's Galilean satellites Caption:Jupiter's four largest moons as seen by the Voyager spacecraft at the correct relative scale. Copyright: Credit:NASA

Title:[3031] Infrared image of Jupiter, its rings and inner moons Caption:A sequence of infrared images of Jupiter taken through a filter to suppress glare from the planet and enhance detection of the rings and faint inner satellites. The six images, running from upper left to lower right, cover a period of about 2 hours, during which the rotation of the planet and the orbital motion of two satellites can be seen. Metis is first seen in the second image and the brighter Amalthea first appears in the third image. Copyright: Credit:NASA Infrared Telescope Facility

Title:[4024] Family Portrait of Jupiter's Great Red Spot and the Galilean Caption:This "family portrait," a composite of the Jovian system, includes the edge of Jupiter with its Great Red Spot, and Jupiter's four largest moons, known as the Galilean satellites. From top to bottom, the moons shown are Io, Europa, Ganymede and Callisto. Copyright: Credit:NASA/JPL