* Ancient Greece (3rd century BC): Aristarchus of Samos proposed a heliocentric model, but it was not widely accepted due to the lack of observational evidence.
* Middle Ages (16th century): Nicolaus Copernicus revived the heliocentric model in his book "De Revolutionibus Orbium Coelestium." He provided mathematical arguments and observations supporting the idea.
* 17th century: Galileo Galilei's observations with his telescope, showing phases of Venus and moons of Jupiter, provided strong evidence for a heliocentric solar system. However, his work was met with opposition from the Church, and he was condemned for heresy.
* 17th and 18th centuries: Johannes Kepler's laws of planetary motion further supported the heliocentric model and provided a more accurate description of planetary orbits. Isaac Newton's law of universal gravitation provided a theoretical foundation for understanding why the planets orbit the sun.
So, while Copernicus is often credited with "discovering" the heliocentric model, the process was much more complex and involved the work of many scientists over centuries.
