1. History of Planetary Rings
13 November 2018

2. 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

3. Interspersed moons and rings
Dotted: Roche
Dashed: Synchronous
Interspersed moons and
rings

4. Jupiter’s rings

5. Saturn with its rings

7. Phoebe’s dust ring

8. Uranus
rings

9. Uranus’
new rings from
Hubble

13. Enceladus and Saturn’s E ring

14. F ring and ‘shepherds’

15. Clump in Saturn’s F ring

17. Daphnis in Keeler Gap

20. Anthe ring

21. The propeller “Bleriot”

23. 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