About 300 B. C., Aristarchus suggested that the sun was at the center of the universe. Why?

The brightness of the planets would change.

The planets appeared to move among the constellations.

The planets always moved opposite to the stars.

The planets disappeared periodically.

The correct answer is option A and B

About 300 B. C., Aristarchus suggested that the sun was at the center of the universe because a) the brightness of the planets would change and b) the planets appeared to move among the constellations.

18 centuries before Copernicus, Aristarchus predicted that all planets orbit the sun. In other words, he suggested the Solar System is heliocentric.