6 months ago
Last edited at 10:06AM on 6/18/2013
I'm not 100% sure. Kepler's law states that the planets revolve around the Sun in elliptical orbits too (as well as the moons' orbits around planets). Perhaps this applies to subatomic particles as well. I don't think anything in the universe can have an "absolutely perfect" spherical orbit, whether you're at the subatomic scale or the cosmic scale.
This is because electrons orbit the nucleus at set distances therefore they cannot move in any other orbital shape. Before the Bohr model was introduced, it was believed that electrons move in a circular orbit however it was determined that they move in an elliptical orbit.