The scientist known for the laws of planetary motion is Johannes Kepler. Kepler, a German mathematician and astronomer, formulated three laws that describe the motion of planets in our solar system. His first law states that planets move in elliptical orbits around the Sun, with the Sun at one focus of the ellipse. The second law explains that a line joining a planet and the Sun sweeps out equal areas during equal intervals of time, indicating that planets move faster when closer to the Sun. Kepler's third law relates the orbital period of a planet to its distance from the Sun, laying the groundwork for modern astronomy.