In a fantastic bit of cosmic sleuthing, scientists have deduced the cause of the tightly wound spiral corrugations seen across the inner rings of Saturn and the rings of Jupiter. The culprit, as reported in the journal Science: impacts from cometary debris. (News release can be found here.)

		Mar 31, 2011:	Tilting Saturn's Rings - This graphic shows in a series of three images how Saturn's rings, after they became tilted relative to Saturn's equatorial plane, would have transformed into a corrugated ring.
		Mar 31, 2011:	Subtle Ripples in Jupiter's Ring - These images, derived from data obtained by NASA's Galileo spacecraft, show the subtle ripples in the ring of Jupiter that scientists have been able to trace back to the impact of comet Shoemaker-Levy 9 in July 1994.

		Sep 21, 2009:	Extensive Spiral Corrugations - Alternating light and dark bands, extending a great distance across Saturn's C and D rings, are seen for the first time in this Cassini image taken as the planet approaches its August 2009 equinox.