Nicolaus Copernicus proposed his theory that the planets revolved around the sun in the 1500s, when most people believed that Earth was the center of the universe. Although his model wasn't completely correct, it formed a strong foundation for future scientists, such as Galileo, to build on and improve humanity's understanding of the motion of heavenly bodies. Indeed, other astronomers built on Copernicus' work and proved that our planet is just one world orbiting one star in a vast cosmos loaded with both, and that we're far from the center of anything.