Copernicus publishes On the Revolutions of Heavenly Spheres

While not accepted for over a hundred years, Copernicus officially published On the Revolutions of Heavenly Spheres, his theory that the sun revolved around the Earth, titled heliocentrism, in 1543. In his publication, he outlines the issues with the current Ptolemaic theory, where the Earth is the center of the universe, surrounded by different spheres which held the workings of the solar system. When Galileo published his famous work, Dialogue Concerning the Two Chief World Systems, there was still enough controversy regarding the heretical viewpoints of heliocentrism that Galileo was put under house arrest and his Dialogue was placed on the Index of Forbidden Books. However, before these two great minds publicly announced their findings, Leonardo da Vinci was already beginning to piece together the same conclusion. In his notebooks, he wrote “the sun does not move,” in large print, implying that he was one of the first discoverers that the sun does not revolve around the Earth. 

 The image retrieved is one of Copernicus' drawings depicting his theory from On the Revolutions of Heavenly Spheres

Copernicus, N. (1995). "On the Revolutions of Heavenly Spheres. Prometheus Books.

Richter, J. (1977). The literary works of Leonardo da Vinci (National Gallery of Art Kress Foundation studies in the history of European art ; no. 5). Berkeley: University of California Press.

Galilei, G., & Finocchiaro, M. (1997). Galileo on the world systems : A new abridged translation and guide. Berkeley: University of California Press.