• DOI:10.1038/277097a0
• Corpus ID: 4232962

Towards a theory for the uranian rings

@article{Goldreich1979TowardsAT,
  title={Towards a theory for the uranian rings},
  author={Peter Goldreich and Scott Tremaine},
  journal={Nature},
  year={1979},
  volume={277},
  pages={97-99}
}

• P. Goldreich, S. Tremaine
• Published 1 January 1979
• Physics, Geology
• Nature

Interparticle collisions, radiation drag and differential precession all tend to disrupt the rings of Uranus. The first two effects lead to radial spreading which would disrupt a free ring in ≲108 yr. We propose that the rings are confined in radius by gravitational torques from a series of small satellites that orbit within the ring system. Differential precession tends to destroy the apse alignment of the elliptical ε ring. We suggest that apse alignment is maintained by the self-gravity of the ring. The resulting mass of the ε ring is ∼5 ×1018 g. Its radial confinement requires (for example) a pair of satellites of mass ∼1019 g, in circular orbits roughly 500 km away on either side of the ring.