Add Yahoo as a preferred source to see more of our stories on Google. Galileo, Kepler and Copernicus with planets and orbital diagrams. In this series, The Week looks at the ideas and innovations that ...

This story is a collaboration with Biography.com. Nicolaus Copernicus developed a celestial model of a heliocentric planetary system, which he described in his landmark work De revolutionibus orbium ...

Ibn-al-shatir's lunar model from which Copernicus is reported to have borrowed in composing his cosmological model. Credit: This work is in the public domain in the United States. New research has ...