[X] My Assistant

[Guest_AlexBlackwell_*]

From the November 25, 2005, issue of Science:

Cassini Discovers a Kinematic Spiral Ring Around Saturn
S. Charnoz, et al.
Science 310, 1300-1304 (2005).
Abstract
Supporting Online Material

See also the accompanying Perspectives piece by Mark Showalter:

Saturn's Strangest Ring Becomes Curiouser and Curiouser
Mark R. Showalter
Science 310, 1287-1288 (2005).
Summary

[Guest_BruceMoomaw_*]

Actually, it seems as though -- for once -- we have a ring phenomenon so simple in nature that even we unscientific dummies can perfectly understand what's going on. (I was intrigued to see, though, that Prometheus will plow through the F Ring in 2009. That should put on quite a display. We are only now coming to grasp just how changable at least the small-scale features of the rings are over time, as Larry Esposito's vision comes true of small "moonlets" in different parts of the rings slowly hauling in other material despite the Roche Limit, and then periodically getting splashed all over the place again by meteoroid impacts.)

[The Messenger]

Actually, it seems as though -- for once -- we have a ring phenomenon so simple in nature that even we unscientific dummies can perfectly understand what's going on.  (I was intrigued to see, though, that Prometheus will plow through the F Ring in 2009.  That should put on quite a display.  We are only now coming to grasp just how changable at least the small-scale features of the rings are over time, as Larry Esposito's vision comes true of small "moonlets" in different parts of the rings slowly hauling in other material despite the Roche Limit, and then periodically getting splashed all over the place again by meteoroid impacts.)

I don't think it is quite that simple, at least if I understand what appears to be happening - why on each revolution do the rings get smaller? If this is what is happening, why haven't all the rings collapsed, and a long time ago? The moonlets should introduce a periodicity, not a progressive march inward. Where is the braking force? Are there some orbital distances that are more stable than others? Are the rings truly an LP record, or is there a Saturn-iancarnation of Bode's Law??? Stay tuned