Astronomy Cast 1.1: Johannes Kepler and His Laws of Planetary Motion (Episode 189)

This podcast was about Johannes Kepler, his contributions to modern astronomy, and how he made his conclusions.  He did not make very good observations because he had bad eyesight, but used Tycho Brahe's observations and data.  Kepler used Brahe's data to construct a workable theory of the solar system.  Kepler's laws of planetary motion state that the planets orbit the sun in a elliptical shape, that a line connecting a planet and the sun sweeps out equal areas during equal amounts of time, and that the square of the orbital period of a planet is directly proportional to the cube of the semi-major axis of the orbit.  As it turns out, Kepler's work was not recognized and accepted until after he was dead.  That must have been pretty frustrating for Kepler: he worked endlessly to develop these laws, and no one recognized them until after he was long gone.  However, Kepler's laws and mathematical calculations are still being taught and used today; a major accomplishment that took time to be realized.