Copernican solar system. 18th-century illustration of the 1543 Sun-centred (heliocentric) solar system of Polish astronomer Nicolaus Copernicus, with notes on the planets plus the twelve signs of the zodiac. The corners show the Sun compared in size to the planets (upper left), a solar eclipse (lower left; lunar eclipse at right), calculations by Dutch astronomer Christiaan Huygens from 'Cosmotheoros' (1698, upper right), and the cosmologies of Ptolemy and Tycho Brahe and Copernicus with a muse (lower right). This depiction is designed after Johann Gabriel Doppelmayr and published by German geographer and cartographer Johann Baptist Homann.