In the initial animation included in the scene, the idea was to show a few seconds of a comfortable orbitable rate for Earth (where Pluto barely moves) and then a comfortable orbital rate for Pluto (where the inner solar system flies). To accomplish that, all the orbital scripts are tied to an attribute in the TimeScale object called counter. At a normal rate, counter advances by 1 for each frame. But then to get the speeding up motion that amount is gradually keyed up to a faster rate.
The orbit lines are paintFX that can fade in and fade out. So all of them are controled by a shader called RingsAlphaController. The Color and Transparency are keyed and drive the incandensance and transparency of the paint fx brush being used on them. Basically Color=black, and Trans=white means the rings are visible. The opposite colors means they are not.
Also included is a paintFX asteroid belt and Ort cloud. As well as Halley's Comet with the correct orbital path and a particle based tail that adjusts direction based on its location relative to the sun.