Editing Prometheus (moon) (section)

==Interactions with F Ring and other moons==

Prometheus is a [[Shepherd moon|shepherd satellite]] for the inner edge of Saturn's narrow [[F Ring]]. [[Pandora (moon)|Pandora]] orbits just outside the F Ring, and has traditionally been viewed as an outer shepherd of the ring; however, recent studies indicate that only Prometheus contributes to the confinement of the ring.<ref name = "LakdawallaE2014">{{cite web
 | last = Lakdawalla | first = E. | author-link = Emily Lakdawalla
 | title = On the masses and motions of mini-moons: Pandora's not a "shepherd," but Prometheus still is
 | publisher = [[Planetary Society]] | date = 2014-07-05
 | url = http://www.planetary.org/blogs/emily-lakdawalla/2014/07010001-ringmoons-shepherds.html
 | access-date = 2015-04-17 }}</ref><ref name="Cuzzi2014">{{cite journal|last1=Cuzzi|first1=J. N.|last2=Whizin|first2=A. D.|last3=Hogan|first3=R. C.|last4=Dobrovolskis|first4=A. R.|last5=Dones|first5=L. |last6=Showalter|first6=M. R.|last7=Colwell|first7=J. E.|last8=Scargle|first8=J. D.|title=Saturn's F Ring core: Calm in the midst of chaos|journal=Icarus|volume=232|date=April 2014|pages=157–175|issn=0019-1035|doi=10.1016/j.icarus.2013.12.027|bibcode = 2014Icar..232..157C }}</ref>

Images from the [[Cassini–Huygens|''Cassini'' probe]] show that Prometheus's gravitational influence creates kinks and knots in the F Ring as it shepherds material from it. The orbit of Prometheus appears to be chaotic, due to a series of four 121:118 [[orbital resonance#Types of resonances|mean-motion resonances]] with [[Pandora (moon)|Pandora]].{{sfn|Renner et al. 2005}} The most appreciable changes in their orbits occur approximately every 6.2 years,{{sfn|Spitale Jacobson et al.|2006}} when the [[apsis|periapsis]] of Pandora lines up with the apoapsis of Prometheus, as they approach to within approximately 1400&nbsp;km. Prometheus is itself a significant perturber of [[Atlas (moon)|Atlas]], with which it is in a 53:54 mean-longitude resonance.{{sfn|Spitale Jacobson et al.|2006}}

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