General Astronomy. Rings ‘n’ Things. Rings are swarms of orbiting particles. Orbits have to be very circular Elliptical orbits will result in collisions, destroying the ring. Rings Have to be Very Flat. Inclined orbits will result in collisions and destruction of the ring.
Rings ‘n’ Things
Inclined orbits will result in collisions and destruction of the ring
Jupiter's ring was discovered by Voyager 1 in a single image that was targeted specifically to search for a faint ring system.
The ring is now known to be composed of three major components. The main ring is about 7000 km wide and has an abrupt outer boundary 129,130 km from the center of the planet.
The main ring encompasses the orbits of two small moons, Adrastea and Metis, which may act as the source for the dust that makes up most of the ring.
At its inner edge the main ring merges gradually into the halo. The halo is a broad, faint torus of material about 20,000 km thick and extending halfway from the main ring down to the planet's cloud tops.
Just outside the main ring is a pair of broad and exceedingly faint gossamer rings, one bounded by the moon Amalthea and the other bounded by the moon Thebe.
Saturn's rings make the planet the most spectacular object in the solar system.
Much of the elaborate structure of some of the rings is due to the gravitational effects of nearby satellites. This phenomenon is demonstrated by the relationship between the F-ring and two small moons that shepherd the ring material.
Shepherd Moons help maintain the sharp edges of rings
A Shepherd Moon Outside a Ring Tends to Drag Stray Particles Back, Causing Them to Fall Back Into the Ring
A Shepherd Moon Inside a Ring Tends to Speed Stray Particles Up, Causing Them to Rise Back Into the Ring
Radial, spoke-like features in the broad B-ring were also found by the Voyagers. The features are believed to be composed of fine, dust-size particles. The spokes were observed to form and dissipate in the time-lapse images taken by the Voyagers. While electrostatic charging may create spokes by levitating dust particles above the ring, the exact cause of the formation of the spokes is not well understood.
Purple > 5 cm
Green < 1 cm
White: too dense
Here is Rhea