Johannes Kepler's house. Cyclist riding past a house where Johannes Kepler (1571-1630) once lived. Johannes Kepler was an eminent German astronomer. He is best known for devising the fundamental laws of planetary motion. This house is located in Graz, Austria, where Kepler was a teacher. Graz is also the place where he is purported to have had an epiphany that led to the publication of his first major work, Mysterium Cosmographicum.