The Sun. Michael Scot, Liber de signis et ymaginibus celi. Wellcome Library MS 509 (ca.1450-60, North Italy), f.23v
The Sun is the largest planet and is in the fourth sphere. The Sun’s sphere is 375,762 miles thick and its diameter is 35,700 miles. It lies in the middle of the planets and its light shines in all directions. For Aristotle, the heat and light of the sun was due to its motion. Its motion was rapid and near to the Earth, unlike the Moon’s motion, which was slow and near or the motion of the fixed stars, which was rapid but distant. The Sun is white or yellow in colour.