Kepler’s Laws of Planetary Motion
1)The planets move in elliptical orbits, with the Sun at one focus.
2) A line between a planet and the Sun sweeps out equal areas of the ellipse in equal amounts of time.
Notes: There is nothing at the other focus or in the center. The Second Law means that planets swing around the Sun faster when they are closer to it. These laws work for anything orbiting around anything due to gravity.