Saturn

This Cassini image shows wavy edges and density waves appearing next to the 300 km wide Encke Gap in Saturn's rings:

A more detailed image of density waves in Saturn's A Ring:

Saturn's rings in natural color as seen by the Cassini spacecraft:

Close view of the brightest part of the F-ring along with twisted wispy material inside the F-ring. The twisting is caused by the gravitational influence of Saturn's moon, Prometheus.

The shepherd moon, Prometheus (about 63 miles across) interacting with the F ring: