Made from 127 raw images received from the Cassini spacecraft on April 17th, this sequence shows the varied structure of the F ring as it is influenced by passing moons, clumps of material and its own twisted composition.
Initially calm, with only background stars marking the passage of time, a passing moon outside the ring casts a thin shadow over it as it travels by. Then the shepherd moon Prometheus cruises along the opposite side, churning up a wake of streaming ring material behind it. This disturbance takes some time to reorganize itself. Then a small thorny nub of material within the ring passes by, followed by a slightly larger globule on the opposite side, seemingly separated from the central channel of the ring, and this is in turn followed by a swollen, hazy section of the F ring in its wake. Eventually this smooths over as well, and the ring splits into several glowing cords just before the final frame.
The Cassini site describes the F ring as containing “kinky ringlets with wandering moons and transient clumps.” An oddity amongst the more orderly and serene discs of the other ring structures, Saturn’s F ring is always a fascinating subject for Cassini’s camera…and even moreso when given movement.
Raw images: NASA/JPL/Space Science Institute. GIF file: J. Major.