The earliest heliocentric model , Copernican heliocentrism , could remove Ptolemy 's epicycles .
The retrograde motion could be seen to be the result of the combination of Earth and planet movement and speeds .
The earliest heliocentric model , Copernican heliocentrism , could remove Ptolemy 's epicycles because the retrograde motion could be seen to be the result of the combination of Earth and planet movement and speeds .