Gravitational Disturbances

Caption NASA:"This mosaic of two Cassini images shows Pan and Prometheus creating features in nearby Rings.
Pan (approx. 28 Km, or about 17 miles across), in the Encke Gap at left, is trailed by a series of edge waves in the outer boundary of the gap. Prometheus (approx. 86 Km, or about 53 miles across at its widest point) just touches the inner edge of Saturn's F-Ring at right, and is followed by a series of dark channels in the Ring, which were caused by the passage of Prometheus through the F-Ring on previous orbits.

This view looks toward the unilluminated side of the rings from about 3° above the Ring-Plane. The images were taken in visible light with the Cassini Spacecraft narrow-angle camera on Aug. 15, 2008. The view was obtained at a distance of approx. 1,2 MKM (746.000 miles) from Pan and Prometheus.
Image scale is roughly 7 Km (about 5 miles) per pixel on both moons".