Any tut on moving stars?

like little dots moving around an atom.

Electrons around a proton?
here's a quick one:

- make a new layer
- make an ellipse using the elliptical marquee tool
- go Edit/Stroke... and stroke Outside, 2 pixels
- with the Brush (Air-) draw one or two electrons on the line
- duplicate the layer once (Layer/Duplicate) (or twice, if you like)
- rotate (Edit/Transform/Rotate) one 60 and the other -60 degrees (if you have 3 electron layers, let the 3rd be)
- make a big, round proton on the center