Every planet follows an oval-shaped path, or orbit, around the sun, called an ellipse.
The sun is located at one focus of the elliptical orbit. This means that planets move faster when they are closer to the sun. The time taken by a planet to make one complete trip around the sun is its period. The squares of the periods of two planets are proportional to the cubes of their mean distances from the sun. He accepted an offer to teach at the Lutheran school in Graz, Austria.