Which astronomer is credited with discovering the concept that planets orbit the sun?

The correct answer is Niccolò Copernicus, who is recognized for formulating the heliocentric model of the universe, which posited that the Earth and other planets revolve around the Sun. Copernicus published his ideas in the book "De revolutionibus orbium coelestium" in 1543, which challenged the long-held geocentric model that placed the Earth at the center of the universe. His work laid the foundation for modern astronomy by shifting the perspective of celestial mechanics.

This revolutionary concept shifted the understanding of the cosmos, influencing subsequent astronomers and eventually leading to further discoveries by figures such as Johannes Kepler and Galileo Galilei, who built on Copernicus’s ideas. Kepler, for instance, later described the laws of planetary motion that clarified the orbits of planets, while Galileo made observations that supported the heliocentric theory.

While Isaac Newton developed the law of universal gravitation and explained the forces that govern planetary orbits, it was Copernicus who first proposed that the planets orbit the Sun, marking a significant turning point in the field of astronomy.