Commentariolus
 Copernicus offered seven postulates: #Celestial bodies do not all revolve around a single point #The centre of Earth is the centre of the lunar sphere—the orbit of the moon around the Earth #All the spheres rotate around the Sun, which is near the centre of the Universe #The distance between the Earth and the Sun is an insignificant fraction of the distance from the Earth and Sun to the stars, so parallax is not observed in the stars #The stars are immovable; their apparent daily motion is caused by the daily rotation of the Earth #Earth is moved in a sphere around the Sun, causing the apparent annual migration of the Sun; the Earth has more than one motion #Earth's orbital motion around the Sun causes the seeming reverse in direction of the motions of the planets.