× Sell your old school/college notes here at www.studyalways.com and make money for free
Johannes Kepler was a German mathematician, astronomer, and astrologer. A key figure in the 17th century scientific revolution, he is best known for his laws of planetary motion, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican Astronomy. These works also provided one of the foundations for Isaac Newton's theory of universal gravitation. In astronomy, Kepler's laws of planetary motion are three scientific laws describing the motion of planets around the Sun. Kepler's laws are now traditionally enumerated in this way:
(1) The orbit of a planet is an ellipse with the Sun at one of the two foci.
(2) A line segment joining a planet and the Sun sweeps out equal areas during equal intervals of time.
(3) The square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit.