Copernicus' heliocentric model — Cropped image of page 9 verso of the autograph manuscript of Nicolaus Copernicus' De Revolutionibus Orbium Coelestium Photo Credit: By Nicolaus Copernicus - Commons file De_Revolutionibus_manuscript_p9b.jpg, Public Domain, https://en.wikipedia.org/w/index.php?curid=58001466
