Heliocentrism was not a commonly supported notion during the 15th century AD. The common notion, well supported by the Catholic Church (supposedly because it was supported by Scripture), was geocentrism. During the age of the Scientific Revolution, Nicolaus Copernicus was a proponent of heliocentrism. It just so happens that today (2/19) is the day that Copernicus was born in 1473. Supporting Copernicus was Galileo, who had a run in with the Catholic Church because of his scientific beliefs. Anyways...Copernicus was not the first to arrive at the idea that the sun is the center of the solar system.
Coming up this week is the chapter 5 test on Greek Civilization. One thing that I learned, and hopefully my students learned, is who first thought of heliocentrism. His name is Aristarchus of Samos. How do we know that it was Aristarchus? Well, it is true that Aristarchus' works have not survived, but the Ancient Greeks were renowned for their writing of history. The idea of heliocentrism by Aristarchus was mentioned by Greek mathematician Archimedes (who first explained the lever and complex pulley system), Greek biographer Plutarch, and Greek philosopher Sextus Empiricus. Just remember that when you look up at the sun one day, or look down at your shadow, it was an Ancient Greek that first figured out that the Earth revolves around the sun.
Source of picture: http://www.nndb.com/people/756/000096468/aristarchus-1.jpeg
Source of info: