[Izzy Dunne]

Yeah, I totally don't understand that alignment stuff. I read that if you made a scale model of Saturn's rings, if it was as thick as a CD, it would have to be four miles in diameter. That's how strict the alignment is.

For what you suggest to be true, they would have to be quite thin in one dimension, and aligned with the planet in that dimension. I don't suggest that that is impossible, but I have no concept of how the physics could make it so.

[Steely Tom]

I think I remember reading somewhere that the structure of the rings has something to do with the gravitational pull of the other moons of the planet; these are called “shepherd moons.” The gentle, cyclic tidal forces they exert over long periods of time (hundreds of millions of years) act to “filter out” all but a very select population of ring particle energy states. As a result, a number of "forbidden orbits" are defined over time; the more moons, the more complex is the structure. The gaps in the rings of Saturn (and, presumably, Uranus) are the result of these tidal forces.

Imagery acquired by the Cassini spacecraft revealed that the rings of Saturn are unbelievably complex, made up of countless thin ring sections that look almost like the grooves of an LP phonograph record.