Kepler’s astronomy, 1609
Johannes Kepler’s book, outlining his theories of planetary motion, made the radical claim that the planets move in ellipses, not perfect circles. Kepler’s work provided significant support for the Copernican theory of a Sun-centred universe.
Kepler’s theories were based on data collected by astronomer Tycho Brahe. He had to make thousands of calculations to work out the peculiarities of Mars’s orbit, describing the experience as ‘my war with Mars.’