Editing Geocentric model (section)

===Copernican system===
{{Main|Copernican heliocentrism}}
In 1543, the geocentric system met its first serious challenge with the publication of [[Copernicus]]' ''[[De revolutionibus orbium coelestium]]'' (''On the Revolutions of the Heavenly Spheres''), which posited that the Earth and the other planets instead revolved around the Sun. The geocentric system was still held for many years afterwards, as at the time the Copernican system did not offer better predictions than the geocentric system, and it posed problems for both [[natural philosophy]] and scripture. The Copernican system was no more accurate than Ptolemy's system, because it still used circular orbits. This was not altered until [[Johannes Kepler]] postulated that they were elliptical (Kepler's [[Kepler's laws of planetary motion#First law|first law of planetary motion]]).