Planetary Rings

Abstract

Planetary rings are the only nearby astrophysical disks, and the only disks that have been investigated by spacecraft. Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 1e-7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close-range and in real-time in planetary rings. We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The main rings of Saturn comprise our system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty rings, likely generated by embedded source bodies, are surprisingly found to sport azimuthally-confined arcs. Finally, every known ring system includes a substantial component of diffuse dusty rings. Planetary rings have shown themselves to be useful as detectors of planetary processes around them, including the planetary magnetic field and interplanetary impactors as well as the gravity of nearby perturbing moons. Experimental rings science has made great progress in recent decades, especially numerical simulations of self-gravity wakes and other processes but also laboratory investigations of coefficient of restitution and spectroscopic ground truth. The age of self-sustained ring systems is a matter of debate; formation scenarios are most plausible in the context of the early solar system, while signs of youthfulness indicate at least that rings have never been static phenomena.

82 pages, 34 figures. Final revision of general review to be published in "Planets, Stars and Stellar Systems", P. Kalas and L. French (eds.), Springer (http://refworks.springer.com/sss)

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Cited by in corpus (17)

• A ring system detected around the Centaur (10199) Chariklo
• Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks
• Detecting ring systems around exoplanets using high resolution spectroscopy: the case of 51Pegb
• Photometric and spectroscopic evidence for a dense ring system around Centaur Chariklo
• Constraints on the size and dynamics of the J1407b ring system
• A Framework for Characterizing Transmission Spectra of Exoplanets with Circumplanetary Rings
• Potential softening and eccentricity dynamics in razor-thin, nearly-Keplerian discs
• Probing the inner boundaries of Saturn's A ring with the Iapetus -1:0 nodal bending wave
• Secular Evolution Driven by Massive Eccentric Disks/Rings: An Apsidally Aligned Case
• A modified "Type I migration" model for propeller moons in Saturn's rings
• ALMA and NACO observations towards the young exoring transit system J1407 (V1400 Cen)
• The missing rings around Solar System moons
• Exploring Exoplanet Dynamics with JWST: Tides, Rotation, Rings, and Moons
• A search for transiting companions in the J1407 (V1400 Cen) system
• A simple model for the location of Saturn's F ring
• Sometimes You Just Can't Put a Ring on It: Setting Constraints on Rings around Moons from Magnetic Fields
• Observing Planetary Rings with JWST: Science Justification and Observation Requirements