NASA's Cassini spacecraft has found evidence of rings around Saturn's second largest moon, Rhea. This would be the first discovery ever of rings around a moon.
A podcast now available at http://www.jpl.nasa.gov/multimedia/podcast/cassini20080306/ and through iTunes and other podcast sites includes space sounds from Cassini data, and an interview with a scientist about the finding.
The discovery was made when Cassini monitored "signatures" of electrons around Rhea. Gaps in the electron signatures on either side of Rhea indicated something was blocking the electrons.