Earth - moon - asteroid orbit game?

While this is a question with a factual answer, it’s pretty mundane and pointless.

There was a flash or java game out there somewhere - There was a planet earth in the center, with a moon orbiting it. You’d click in it to add ‘asteroids’ and they’d be affected by the gravity of the earth & the moon.

I think I first saw it in a thread here, but I’ve searched and googled and just can’t find it!

Anyone know what I’m talking about? Thanks!

http://www.colorado.edu/physics/2000/applets/satellites.html