Brightness variations in the F-Ring may be due to clumping in the ring material. The features are seen at the top and again near the left edge of the ring in this image. The “gap” in the ring (left center) is not real but is the location of a reseau mark on the camera’s vidicon tube. These bright features in the F-Ring appear to move at the orbital rate of the ring particles and may be larger bodies or thicknesses in the rings. Saturn’s thirteenth and fourteenth satellites, which orbit on either side of the F-Ring, may act like “sheepdogs,” herding the F-Ring particles between them. Less than 100 kilometers (60 miles) wide, the F-Ring is located outside of the A-Ring. Satellite 14, discovered by Voyager 1, is seen just inside the F-Ring.] The Satellites [Illustration: In only twelve hours, Saturn’s satellites grew from names in ancient mythology into dazzling worlds with personae of their own. As Voyager 1 sailed through the Saturn system, it returned photographs of Mimas, Enceladus, Tethys, Dione, and Rhea—all part of a class of intermediate-sized icy bodies heretofore unstudied by planetary spacecraft. All but Enceladus show heavily cratered surfaces, evidence of aeons of meteorite bombardment. Enceladus hints at internal processes, as yet unidentified, which may have erased from its surface the evidence of early bombardment—but we must await Voyager 2’s arrival next August to better understand this body.] [Illustration: 11/9/80 4.5 million km (2.8 million mi) The surface of giant Titan, now dethroned from its seat as the solar system’s largest satellite (Jupiter’s Ganymede is larger), remains an enigma, shrouded beneath thick layers of haze.] [Illustration: 11/12/80 22,000 km (14,000 mi) Tiny moons—three new ones and three confirmed from previous sightings—may tell us much about ring dynamics since gravitational forces from satellites probably influence the ring structure. Two of these tiny moons are on the verge of collision in the same orbit, while several others appear to bound the A- and F-Rings. Iapetus, whose two hemispheres differ dramatically in brightness, was photographed in its orbit, almost 3.6 million kilometers (2.2 million miles) from the planet.] [Illustration: 11/12/80 425,000 km (264,000 mi)