NASA / JPL-Caltech / SSI / montage by Emily Lakdawalla
Ten shots of the F ring
Cassini captured these 10 views of the F ring on July 5, 2008, as part of a survey to understand the F ring's structure. Prometheus, the inner shepherd of the F ring, is visible in the leftmost image (overexposed).
NASA / JPL-Caltech / SSI / QMUL
Fans in the F ring
This unusual view of the F ring is a mosaic of 10 images, reprojected to take the bend out of the ring, and then compressed by a ratio of 33 to 1 in order to reveal the odd structures that cross the rings. The moon Prometheus is a bright streak at the extreme right edge of the mosaic. The F ring has several strands that are crossed by dark channels, gores caused by Prometheus' once-per-orbit collision with the ring. Above each gore is a set of fans. The fans (marked "F" in the annotated version below) can be seen developing as a series of channels within the F ring's particles. They appear to have a common origin but spread outward radially in different directions. Gravitational perturbations on ring material by a moonlet or clump of material can create these fans. The moonlet or clump orbits more or less elliptically compared to the rest of the F ring. It is probably embedded in the ring and causes the base of the fan channels to meet.