September 30, 1550 - October 20, 1631
Michael Maestlin was a German astronomer and mathematician, known for being the mentor of Johannes Kepler.
Maestlin studied theology, mathematics, and astronomy at the Tübinger Stift in Tübingen, a town in Württemberg. In 1580 he became a Professor of mathematics, first at the University of Heidelberg, then at the University of Tübingen were he taught for 47 years from 1583. In 1582 Maestlin wrote a popular introduction to astronomy.
Among his students was Johannes Kepler (1571-1630). Although he primarily taught the traditional geocentric Ptolemaic view of the solar system, Maestlin was also one of the first to accept and teach the heliocentric Copernican view. Maestlin corresponded with Kepler frequently and played a sizable part in his adoption of the Copernican system. Galileo Galilei's adoption of heliocentrism was also attributed to Maestlin .
The first known calculation of the (inverse) golden ratio as a decimal of "about 0.6180340" was written in 1597 by Maestlin in a letter to Kepler.
Maestlin catalogued the Pleiades cluster on December 24, 1579. Eleven stars in the cluster were recorded by Maestlin, and possibly as many as fourteen were observed. He also observed the occultation of Mars by Venus on October 3, 1590, at Heidelberg.
In Jules Verne's Cinq semaines en ballon (Five Weeks in a Balloon) the character of Joe, the manservant, is described as enjoying, "in common with Moestlin, Kepler's professor, the rare faculty of distinguishing the satellites of Jupiter with the naked eye, and of counting fourteen of the stars in the group of Pleiades, the remotest of them being only of the ninth magnitude."
The Lunar crater Maestlin, the Lunar rille Rimae Maestlin and the asteroid 11771 Maestlin, discovered in 1973, are named in his honor.