Johann Kepler was a German astronomer. He was born in 1571 at Weil and died in 1630 after contracting a fever. At the age of seventeen he was admitted to the University of Tubingen and in 1594 was appointed professor of mathematics and astronomy at Graz. In 1600 he went to Prague as an assistant to Tycho Brahe whom he succeeded the following year. During the next 25 years Johann Kepler was astronomer and mathematician to Upper Austria, at Ulm and to Wallenstein. Research Johann Kepler