
Kepler’s third law
Fig. 1.13 . The orbital periods of the planets are plotted against their semimajor axes, using a logarithmic scale. The straight line that connects the points has a slope of 3/2, thereby verifying Kepler’s third law that states that the squares of the orbital periods increase with the cubes of the planetary distances. This type of relation applies to any set of bodies in elliptical orbits about a much larger mass, including Jupiter’s four largest satellites shown in the inset.
Copyright 2010, Professor Kenneth R. Lang, Tufts University

