According to Ptolemy, all the celestial objects such as the moon, the sun and other planets moves around the earth in a circular path. This means that the earth is located at the center of the solar system.
He made a combination of eccentricity and an epicyclic model in order to explain the motion of planets.
This concept was created because he noticed that some of the planets moves in the western direction, rather than in the eastward direction, with respect to the stars that are present in the sky.
