Mars

Mars. Michael Scot, Liber de signis et ymaginibus celi. Wellcome Library MS 509 (ca.1450-60, North Italy), f.23v

Mars completes its circuit in two years. The thickness of its sphere is 218,083,446 miles and its diameter is 7,572 miles. Mars is fiery and radiant, and causes harm and wars in the sublunar realm.