The true proportions of the Copernican cosmic system, 1745.
© Science Museum / Science & Society Picture Library
Engraving showing the orbits of the planets in the solar system, minus Neptune and Pluto which had not yet been discovered. Polish astronomer Nicolaus Copernicus (1473-1543) is considered to be the 'father' of modern astronomy and founder of heliocentric cosmology. Prior to the work of Copernicus, the Earth was considered to be the stationary centre of the universe, a notion first advocated by the Egyptian astronomer Ptolemy (c 90-168 AD). Copernicus was the first to describe a Sun-centred universe, in which the Earth is merely one of the planets revolving around the Sun and rotating on its axis. Illustration from 'Mathematischer Atlas' (Mathematical atlas) by Tobias Mayer (1723-1762) published in Augsburg in 1745.