Who was the first to formulate a comprehensive heliocentric model?

The formulation of the comprehensive heliocentric model is primarily attributed to Nicholas Copernicus. In his seminal work, "De revolutionibus orbium coelestium" (On the Revolutions of the Celestial Spheres), published in 1543, Copernicus proposed that the Sun, rather than the Earth, is at the center of the universe, and that the planets, including Earth, revolve around it. This model marked a significant departure from the long-held geocentric view, where the Earth was believed to be the center of the universe.

Copernicus's heliocentric model laid the groundwork for a new understanding of celestial mechanics and was crucial for the scientific revolution that followed. The advancements in astronomy by later figures, such as Galileo and Kepler, built upon Copernicus's ideas, but it was he who first articulated a comprehensive model that displaced the Earth from the center of the universe. His work fundamentally changed the course of astronomy and science as a whole, making him a pivotal figure in the history of astronomy.