Kepler’s laws of planetary motion
Newton demonstrated that the gravitational force is responsible for Kepler’s laws of planetary motion. Consider Kepler’s 3rd law (in its original form): p2 = a3, and then the form Newton derived for it. Because the Sun’s mass plays a role in determining the p values for a given value of a, comparing values of p and a for planets around other stars can provide insight into whether that star is more or less massive than the Sun. Rank the hypothetical planets based on their host star’s mass by examining their semimajor axis (a) and period (p) values.
