•1563 “Conjunction” Jupiter and Saturn show
problems with Ptolemaic
predictions of positions.
•
•1572 Tycho’s “supernova” challenges ideas of
unchanging nature of the
heavens
–Lack of
parallax shows it was at least as far away as the moon.
–
•1576 –
1596 Most precise observations of
positions of the planets
•
•
•1596 Moves to Prague, hires Johannes Kepler as
assistant
•
•1601 Collapses,
requests Kepler be appointed his replacement, then dies