In Astronomy’s 2022 list of the 20 greatest astronomers of all time, Associate Editor Michael Bakich ranked Tycho Brahe No. 2, second only to Galileo, noting: “Danish astronomer Tyge (Tycho) Ottesen Brahe was history’s greatest pre-telescopic observer.”
Born Dec. 14, 1546, Tycho was raised by an uncle who funded his education at the University of Leipzig. There, he discovered that most existing publications of stellar and planetary positions were hugely inaccurate, and decided to devote his life to rectifying this problem. Among the career highlights that prompted Bakich to rank him so high: “Although Brahe didn’t have a telescope, he constructed many observing instruments: several quadrants, an armillary sphere, a sextant, and a large globe. Two of his famous observations were of the supernova that appeared in 1572 (now called Tycho’s Nova) and the Great Comet of 1577. When he measured their positions, he saw no parallax, meaning that their distances placed them beyond the Moon.”
Tycho died Oct. 24, 1601, in Prague, leaving his data to his protégé, Johannes Kepler. His careful observations allowed Kepler to determine the laws of planetary motion; these laws, in turn, became the basis for the work of Isaac Newton.
