1-153-662 - Ann Ronan Picture Library/Heritage-Images

Copernicus' heliocentric model of the Universe, 1543. Polish astronomer Nicolaus Copernicus (1473-1543) is considered to be the father of modern astronomy and founder of heliocentric cosmology. Prior to his work, the Earth was considered to be the stationary centre of the universe, a notion first advocated by the Egyptian astronomer Ptolemy. Copernicus' pioneering work De revolutionibus orbium coelestium (The Revolutions of Celestial Spheres) describes his idea of a Sun-centred universe, in which the Earth is merely one of the planets revolving around the Sun and rotating on its axis. From De revolutionibus orbium coelestium. (Nuremberg, 1543).