Explanation: What's causing those strange dark streaks in the rings of Saturn?
Prometheus. Specifically, an orbital dance involving
Saturn's moon Prometheus keeps creating unusual light and dark streamers in the
F-Ring of Saturn. Now
Prometheus orbits Saturn just inside the thin
F-ring, but ventures into its inner edge about every 15 hours. Prometheus' gravity then
pulls the closest ring particles toward the 100-km moon. The result is not only a stream of bright
ring particles but also a
dark ribbon where ring particles used to be. Since
Prometheus orbits faster than the ring particles, the icy moon pulls out a new streamer every pass. Sometimes, several streamers or
kinks are visible at once. The
above photograph taken in mid-January by the robotic Cassini Spacecraft orbiting Saturn. The oblong moon Prometheus is visible on the far left of the image.