Saying it' maths is simplifying it a bit. They use simulations. They can simulate how an object orbits and eventually fall down to earth. They can test those si

Saying it' maths is simplifying it a bit. They use simulations. They can simulate how an object orbits and eventually fall down to earth. They can test those simulations everyday by predicting where a know object in orbit will be in the future. Multiply that by a billion and you can predict that earth's rings would have fall down eventually.