Algodoo

The blue object represents saturn, the purple object represents one of saturns larger minor moons, and the green object represents the smaller moon. Watch the green object's path relative to the purple one. What happens may surprise you! Instead of being pulled into the object when it gets near, it makes a U-turn and goes back around to the other side, and does it again! The interactions these objects have with each other form what is known as a horseshoe orbit, named after the shape the smaller object traces relative to the larger object. It is hard to get these exacly right, and the simulation only works for an orbit or two, but if you can create a better model, send it to me!