He was a Greek astronomer who lived in the 3rd century BC. While his theory was largely ignored in his time, he proposed a heliocentric model where the Earth and other planets revolved around the Sun.
This was in contrast to the prevalent geocentric model of the time, championed by Ptolemy, which placed the Earth at the center of the universe.
It was only much later, with the work of Copernicus in the 16th century, that the heliocentric model gained traction and eventually became the accepted model of our solar system.
