History of Planetary Rings 13 November 2018
Key ideas for ring origin Roche limit Clumping in the tidal environment Genetic relation of moons and rings: not just brothers and sisters, but parents and children Theories for ring formation Cassini results show the rings are young, but provides no good models
Interspersed moons and rings Dotted: Roche Dashed: Synchronous Interspersed moons and rings
Jupiter’s rings
Saturn with its rings
Phoebe’s dust ring
Uranus rings
Uranus’ new rings from Hubble
Enceladus and Saturn’s E ring
F ring and ‘shepherds’
Clump in Saturn’s F ring
Daphnis in Keeler Gap
Anthe ring
The propeller “Bleriot”
Theories for the origin of Saturn's rings One theory suggests that the ring particles are leftover debris from the formation of the planet itself. Another idea is that the rings are debris from a satellite that was unable to form. Probably the most likely theory is that the particles are the result of an icy satellite that was shattered by an impact with a comet. A recent proposal by Canup is they are from a differentiated moon, torn apart by tides