Trail behind a comet....
... The trail from the comet acts and looks pretty much like this. Of course, the comet's trail is made up of ice crystals, rocky and dust materials.
Think of how the above would happen in a vaccum and far away from the gravity pull of another body besides the comet.
I know, Dan, that was probably one of my worst analogies yet.
Marcia (needs lots more coffee today.)
