1) Copernicus probably hit upon his main idea sometime between 1508 and 1514. For years, however, he delayed publication of his controversial work, which contradicted all the authorities of the time.
2) The book opened the way to a truly scientific approach to astronomy. It had a profound influence on later thinkers of the scientific revolution, including such major figures as Galileo, Johannes Kepler, and Isaac Newton.
3) According to legend, Copernicus received a copy as he was dying, on May 24, 1543.
4) The historic book that contains the final version of his theory, De revolutionibus orbium coelestium libri vi ("Six Books Concerning the Revolutions of the Heavenly Orbs"), did not appear in print until 1543, the year of his death.