Aristarchus of Samos, often referred to as the Copernicus of antiquity, was a Greek astronomer and mathematician, that laid
the foundation for much scientific examination of the heavens. Aristarchus was the first to propose not only a heliocentric universe, but one larger than any of the geocentric universes proposed by his predecessors.
Aristarchus was a student of Strato of Lampsacus, who was head of Aristotle's Lyceum. However, it is reasonable to believe that Aristarchus did not study with Strato in Athens but rather that he studied with him in Alexandria. Strato became head of the Lyceum at Alexandria in 287 BC and it is likely that Aristarchus studied with him there, starting his studies shortly after that date.
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 by Johannes Kepler and Isaac Newton nearly 2000 years later.
Aristarchus was born on the island of Samos in Greece, around 310 BC, and died around 230 BC. He was known as a celebrated astronomer even during his life time.
His only extant work is a short treatise: "On the Magnitudes and Distances of the Sun and Moon", where he used geometry to find the distances to the Sun and Moon. Although the heliocentric system is not mentioned in the treatise, a quotation in the Arenarius of Archimedes from a work of Aristarchus proves that he anticipated the great discovery of Copernicus.
Archimedes, who was twenty-five years younger than Aristarchus, wrote: “His hypotheses are that the fixed stars and the Sun remain unmoved, and that the Earth revolves about the Sun in the circumference of a circle, the Sun lying in the middle of the orbit.” Archimedes also added that according to Aristarchus, who is in contradiction to “the common account” of astronomers, the universe is many times larger than generally assumed by astronomers, and the fixed stars are at an enormous distance from the Sun and its planets.
Aristarchus also proposed an ancient Greek time period, his "Great Year" of 4868 solar years. Embedded in the Great Year was a length of the month agreeing with the Babylonian value to 1 part in tens of millions, decades before Babylon is known to have used it.