Saturday, July 03, 2004

Ring Cleaning

While some of us are busy Hoovering up spiders, Cassini has imaged Saturn's elusive shepherd moon Pan. The tiny moon is the caretaker of the 168-mile wide Encke gap in Saturn's rings. As it zips around Saturn, it keeps its own little orbit within the rings free of dust and debris.

Pan's existence was predicted before it was first observed due to its gravitational influence on the surrounding rings. The 12-mile wide moon was finally spotted by scientist Mark R. Showalter in a nine year old Voyager photograph in 1990.

And now on Cassini's return to Saturn, Pan has been spotted again -- still dutifully keeping its part of the rings tidy.