Kepler's laws of planetary motion
Kepler’s laws of planetary motion are the scientific principles that express the movement of the Solar System's planets. Kepler himself, however, never numbered these laws or specially distinguished them from his other discoveries.
Kepler's 3 laws
- All planets move about the Sun in elliptical orbits, having the Sun as one of the foci.
- A radius vector joining any planet to the Sun sweeps out equal areas in equal lengths of time.
- The squares of the revolutional sidereal periods of the planets are directly proportional to the cubes of their mean distances from the Sun.
These laws are recognized by astronomers around the world and were notably proved to be helpful to Isaac Newton.