Figure 12-20: R I V U X G
Details of Saturn’s F Ring This Cassini image shows Saturn’s F ring (compare Figure 12-19). The bright central ringlet is about 50 km wide. As the small satellite Prometheus orbits just inside the F ring, its gravitational pull causes disturbances called “drapes” in the ringlets. The narrowness of the F ring is the result of gravitational forces exerted by Prometheus and another small satellite called Pandora (see Section 12-11). This image also shows two divisions in the A ring, the Encke gap and the Keeler gap.

(NASA/JPL/Space Science Institute)