born 0441; 310 BC
died 0441; 230 BC
Greek astronomer.
His advanced ideas on the movement of the Earth (which he asserted revolved around the Sun) are known from Archimedes and Plutarch . His only surviving work is the short treatise "On the Sizes and Distances of the Sun and Moon"; though the values he obtained are inaccurate, he showed that the Sun and stars are at immense distances. A peak in the centre of a lunar crater named for him is the brightest formation on the Moon.