ケプラーの法則

Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun. They state that: 1) planets move in elliptical orbits with the Sun at one focus; 2) a line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time; and 3) the square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit.