While others had proposed similar ideas before, Copernicus's *De Revolutionibus Orbium Coelestium* (On the Revolutions of the Heavenly Spheres), published in 1543, was a landmark work that laid out a detailed heliocentric model of the solar system. His work was revolutionary for its time, as it challenged the prevailing geocentric model (Earth-centered) that had been accepted for centuries.
It's important to note that Copernicus was not the first to propose a heliocentric model. Greek astronomers like Aristarchus of Samos had proposed it centuries earlier, but their ideas were not widely accepted. Copernicus's work, however, provided a more complete and mathematically sound explanation for the observed motions of the planets, and it eventually led to the scientific revolution.
