Travelers moving south on the surface of the Earth see different constellations on the horizon, near the poles, and overhead. Elephants had been seen to the East of Greece in India and to the West of Greece in Morocco so the two locations must really not be too far apart iv. Theory material falling to a center would take on a spherical shape presaging Newtonian gravity. Only for a sphere do bodies fall perpendicular to the surface everywhere. If the Earth is spherical , then, by analogy, so are all the other celestial bodies.
All celestial motion is in circles, and all celestial bodies are spheres.
The Earth is motionless at the center of the very universe. He invented the method of describing the brightness of star which is still in use. Brief description of the Ptolemaic model Planets move on epicycles, the centers of which move on the deference. In even greater detail, because Venus and Mercury were never observed far from the Sun, Ptolemy had to model them with the centers of their deferents along a line joing the Earth to the Sun. And the fifth material, the aether, or quintessence, from which celestial objects were made.