Brahe (right) and Kepler discussing observations on the movement of the planet Mars. Tycho Brahe (December 14, 1546 - October 24, 1601) was a Danish astronomer and alchemist. After becoming interested in astronomy as a student in Copenhagen, Tycho Brahe realized the difficulty of making accurate measurements of celestial bodies with the instruments of the day. His designs for new methods and devices won him great fame. As an astronomer he worked to combine the geometrical benefits of the Copernican system with the philosophical benefits of the Ptolemaic system into his own model of the universe, the Tychonic system. He was the last of the major naked eye astronomers, working without telescopes for his observations. Tycho is credited with the most accurate astronomical observations of his time, and the data was used by his assistant, Johannes Kepler, to derive the laws of planetary motion. Johannes Kepler (December 27, 1571 - November 15, 1630) was a |