Aristarchus of Sámos

Aristarchus of Sámos (310?-250?bc), Greek astronomer who was the first to assert that the earth revolves around the sun. His belief that the earth revolves around the sun is known only through the writings of Greek mathematician and inventor Archimedes; none of the works written by Aristarchus on the subject have survived. In his only surviving work, On the Dimensions and Distances of the Sun and Moon, Aristarchus described a method for estimating the relative distances of the sun and moon from the earth. Although his method was essentially correct, his estimates were wrong because of his inadequate knowledge of mathematics and his lack of accurate instruments.