31. It was the belief in the geocentric reality of the observable world, unchanging and immobile. 32. Unlike Akari, which had a geocentric orbit, SPICA will be located at Sun Earth. 33. More technically, it is the mean semi-major axis of the geocentric lunar orbit. 34. The Geocentric model was developed primarily by Greek philosopher Aristotle and Greco-Egyptian astronomer Ptolemy. 35. Geocentric theory presumes the two inner planets to be closer to the Earth than the Sun.36. Ancient Greek, ancient Roman and medieval philosophers usually combined the geocentric model with a spherical Earth. 37. The lack of any observable parallax was considered a fatal flaw in any non-geocentric theory. 38. While maintaining the physical reality of the geocentric model, he criticized elements of the Ptolemic models. 39. In these geocentric models the stars and planets are carried around the Earth on spheres or circles. 40. The name is an analogue to the term " geocentric orbit " for an orbit around Earth.
