Aristarchus (Greek: Ἀρίσταρχος; 310 BC - ca. 230 BC) was a Greek astronomer an mathematician, born on the island of Samos, in Greece. He was the first person to present an explicit argument for a heliocentric model of the solar system, placing the Sun, not the Earth, at the center of the known universe (hence he is sometimes known as the "Greek Copernicus"). He was influenced by the Pythagorean Philolaus of Kroton, but in contrast to Philolaus he had both identified the central fire with the Sun, as well as putting other planets in correct order from the Sun. His astronomical ideas were rejected in favor of the geocentric theories of Aristotle and Ptolemy until they were successfully revived by Copernicus and extensively developed and built upon by Johannes Kepler and Isaac Newton nearly 2000 years later.