He was by birth a Swabian Protestant, was educated at Tubingen as a pupil of Apian, and, after a period of travel, was settled as deacon in the little parish of Backnang, when the comet of 1577 gave him an occasion to apply his astronomical studies.

His minute and accurate observation of it is to this day one of the wonders of science.

It seems almost impossible that so much could be accomplished by the naked eye.

His observations agreed with those of Tycho Brahe, and won for Maestlin the professorship of astronomy in the University of Heidelberg.

No man had so clearly proved the supralunar position of a comet, or shown so conclusively that its motion was not erratic, but regular.