Copernicus publishes On the Revolutions of the Heavenly Spheres

Nicolaus Copernicus, a canon of Frombork in Poland, spent decades developing a model in which the Earth is a planet that turns daily on its axis and travels around a motionless Sun once a year. His book De revolutionibus orbium coelestium was printed in Nuremberg in 1543, and legend holds that he received a copy on his deathbed. The system explained the apparent backward loops of the planets simply, though it still used circles and so was not much more accurate than Ptolemy's. Over the next century Kepler, Galileo and Newton turned the idea into the foundation of modern astronomy.

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