Tall structures, presumably caused by moonlets, near the outer edge of Saturn’s A Ring, photographed by Cassini, 26 July 2009.  (The photos in this sequence weren’t taken frequently enough to actually follow the motion of individual peaks.)  More descriptions here; the tallest of the peaks is about 2.5km above the ring plane.

Tall structures, presumably caused by moonlets, near the outer edge of Saturn’s A Ring, photographed by Cassini, 26 July 2009.  (The photos in this sequence weren’t taken frequently enough to actually follow the motion of individual peaks.)  More descriptions here; the tallest of the peaks is about 2.5km above the ring plane.