This is the new version of Comet Course. It's slower, so I would suggest using turbo mode in the flash player. This version is much more accurate though, although the old version is still very cool. Shoot a commet into a field of up to 3 planets! Click and drag the planets around, and click them to set their mass. I suggest not making the mass more than about 300. Click the screen to change the gravitational constant. Click and drag the ball to determine it's starting velocity. This is actually what a ball will do in the given circumstance. The little green dot shows the ball's velocity. Also, if you want the ball to start somewhere besides the lower left corner, simply put your mouse where you want it to start and press space.