DPS 2001 meeting, November 2001
Session 29. Rings I
Oral, Chair: L. Spiker, Thursday, November 29, 2001, 11:40am-12:40pm, Regency GH

[Previous] | [Session 29] | [Next]

[29.06] Saturn's Coupled Companions, Prometheus and Pandora

L. Dones, H. F. Levison (Southwest Research Institute), J. J. Lissauer (NASA Ames Research Center), R. G. French, C. A. McGhee (Wellesley College)

Saturn's moons Prometheus and Pandora, the putative shepherds of the F Ring, orbit Saturn at rates that differ significantly from the rates at the time of the Voyager flybys in 1980/1981 (C.~A. McGhee et~al., Icarus 152, 282-315, 2001). Specifically, Prometheus is running slow, and Pandora is running fast. Soon after Prometheus' lag was discovered, collisions between Prometheus and the F Ring, occurring every ~19~years when their apses were anti-aligned, were proposed to explain the lag (C.~D. Murray and S.~M. Giuliatti Winter, Nature 380, 139-141, 1996). Pandora's orbital advance cannot be explained in this way, since it does not come as close to the F~Ring as Prometheus does. Instead, chaos is likely to be important for Pandora (F.~Poulet and B. Sicardy, MNRAS 322, 343-355, 2001). The recent discovery that Prometheus and Pandora have nearly equal and opposite longitude anomalies suggests that their motions are coupled (R.~G. French et~al., this meeting). We will present numerical integrations of bodies with orbits similar to those of Prometheus and Pandora, and will discuss ways in which two- and three-body resonances involving Saturn's inner moons might couple the orbits. We thank the NASA Planetary Geology & Geophysics program for grants to LD, HFL, JJL, and RGF, and to STScI for grant GO­06806.01­95A to RGF.

If you would like more information about this abstract, please follow the link to http://www.boulder.swri.edu/~luke/. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.

[Previous] | [Session 29] | [Next]