Tycho Brahe isn't as famous as Galileo or Copernicus, but in some circles he's considered the father of modern astronomy. He spent much of his life compiling the world's first truly accurate and complete set of astronomical tables -- all before the invention of the telescope. Brahe's assistant, Johannes Kepler, later used the tables to deduce the laws of planetary motion. In 1628 Kepler published the Rudolphine Tables, a list of remarkably accurate logarithmic astronomical tables based on Brahe's observations and Kepler's subsequent analysis.
In 1566 Brahe lost most of his nose in a duel, and wore a metal replacement the rest of his life.