Tycho Brahe (1546-1601)

Acknowledge as one of the greatest observational astronomers who ever lived, Tycho (TY-ko) Brahe (BRAH-ee) managed to make enormous strides without the help of telescopes. During his lifetime he discovered that comets are the product of interplanetary space rather than of the earth, as had long been believed. His inventions included a number of highly accurate instruments, and among his publications was a most valuable table of refractions. Toward the end of his life, he was joined by Johannes Kepler, who functioned as Brahe’s assistant and, after the great astronomer’s death, continued the work his friend had begun.