Who was Tycho Brahe?

Tycho Brahe (14 December 1546 - 24 October 1601) was a Danish nobleman, astronomer, astrologer, alchemist and writer, best known for his astronomical and especially, planetary, observations. He was described as "the first competent mind in astronomy to feel ardently the passion for exact empirical facts."

Brahe was born on the Danish Scanian peninsula, an heir to several of the best known noble Danish families. He received a comprehensive education, being strongly drawn to astronomy and the development of more accurate astronomical tools, which in his time were fairly rudimentary. Developing his own model of the universe, and designating it the Tychonic system, he correctly saw the moon as orbiting the earth and the planets orbiting the sun, but incorrectly saw the sun as orbiting the earth. The last of the major naked eye astronomers, he disputed Aristotle's belief of an unchanging celestial realm.

Brahe's astronomical fervor dominated his life and his unquenchable fire was always for better instrumentation with which to measure the cosmos, realizing that naked eye astronomy was far from perfect.

Later in life he worked with Johannes Kepler at Brahe's observatory at Benatky Nad Jizerou. After Brahe's death Kepler used Brahe's data in his three laws of planetary motion.