Planets
Move the planets around their respective orbits.
It was not until the 17th century that a German astronomer by the name of Johannes Kepler was able to explain planetary motion. It was originally believed that the orbits of planets occured in spheres which were nestled in pyramids and other polyhedra. Kepler soon realized that he was unable to fit the orbit of Mars inside a sphere and thus realized that their orbits were instead in the form of an ellipse.
While kepler was the one who was successfully able to correctly describe the orbit of the planets, it was Newton's laws of motion and gravity that were able to explain why such motion occured. Newton explained that any object that is affected by the gravitational pull of another object will have its orbit occur in the shape of an ellipse. Planets & satelites follow elliptical orbits around the sun. Comets follow elliptical orbits around the solar system.