Aristarchus of Samos (Samos, c. -310 / Alexandria, -230) was a Greek astronomer and mathematician, the first scientist to propose the heliocentric model of the Solar System, placing the Sun, and not the Earth, at the center of the known universe. He made this proposal after studying the distance and size of the Sun and having determined that the Sun was much larger than Earth. Aristarchus' model was opposed to the commonly accepted geocentric system, defended by Plato and Aristotle, which assumed the Earth as the center of the universe, around which the Sun, the Moon and all the planets revolved. The geocentric model seemed more logical based on what was observed from Earth, but Aristarchus deduced that it must have been the Sun that occupied the center and not Earth. Of the Aristarchus model, only remain quotes from Plutarch and Archimedes.
