Dusty Saturn: Planetary Slingshot and Ice Volcanoes

The dust detector CDA (Cosmic Dust Analyser) instrument on board the Cassini/Huygens spacecraft started to detect Saturnian dust particles already half a year before the spacecraft started its exploration of the Saturnian system. The sensor registered short collimated streams of nanometre-sized dust particles which were expelled from the inner Saturnian system into the interplanetary space. Based on the dynamical properties of the stream particles, Saturn's A ring was found to be one of the particle sources. This discovery offered the unexpected opportunity to analyze material of Saturn's main ring in situ which is not accessible otherwise. Observations during a close Cassini fly-by of the icy moon Enceladus gave strong indication for ice volcanism. This discovery eventually explained why this moon is effectively replenishing Saturn's vast E-ring with fresh dust particles.