* Nicolaus Copernicus: He is considered the "father" of the heliocentric model. In his book "De Revolutionibus Orbium Coelestium" (On the Revolutions of the Heavenly Spheres), published in 1543, he proposed that the Sun, not the Earth, was the center of the solar system.
* Galileo Galilei: While Copernicus laid the groundwork, Galileo provided much of the observational evidence to support the heliocentric model. He used his telescope to make groundbreaking discoveries like the phases of Venus and the moons of Jupiter, which were difficult to explain with the geocentric model.
It's important to remember that there were other individuals who believed in heliocentricity before Copernicus and Galileo, though their ideas were not as widely known or influential.
