While ancient Greek philosophers like Aristarchus of Samos had proposed heliocentric models, Copernicus's work, *De Revolutionibus Orbium Coelestium* (On the Revolutions of the Heavenly Spheres), published in 1543, was the first detailed and influential model to challenge the prevailing geocentric (Earth-centered) model of Ptolemy.
Copernicus's heliocentric model, though still imperfect, laid the foundation for the modern understanding of our solar system.
