17:46, 7 March 2007 (UTC)RicefountianJohannes Kepler's primary contributions to astronomy/astrophysics were his three laws of planetary motion. Kepler, a brilliant German mathematician, derived these laws, in part, by studying the observations of the legendarily precise Danish astronomer Tycho Brahe. The article on Johannes Kepler gives a less mathematical description of the laws, as well as a treatment of their historical and intellectual context. [[Kepler's laws of planetary motion]]

Isn't it nice to know we have such exact time stamps?