Wiggly Ring

Saturn's outermost ring, the F Ring, shows wiggles, spikes, curls, and other structures in these two images from the Cassini spacecraft, which were snapped about two months apart. Saturn itself has been blocked out. Most of the structures (which have been exaggerated) are caused by the gravitational pull of the moon Prometheus. Others, such as the spoke at top left in the left image, are caused by odd objects that may be tiny moons or clumps of ring material. Cassini has spotted many of these objects in the F Ring, which spans about 175,000 miles (280,000 km). [NASA/JPL/SSI]