Tycho was the preeminent observational astronomer of the pre-telescopic period, and his observations of stellar and planetary positions achieved unparalleled accuracy for their time. After his death, his records of the motion of the planet Mars enabled Kepler to discover the laws of planetary motion which provided powerful support for the Copernican heliocentric theory of the solar system. Tycho himself was not a Copernican, but proposed a compromise system in which the planets other than earth orbited the sun while the sun orbited the earth.
While a student, he lost part of his nose in a duel. For the rest of his life, he wore a silver replacement.
Because he disagreed with the new king of his country, he moved to Prague in 1599. There he built a new observatory and worked there until his death.