The Solar System as seen from earth. This model shows the five planets and moon as Ptolemy described them in his famous book, "The Almagest". It describes accurately all the naked eye phenomena of our Solar System. The fact that most of the motions described by this geocentric system are incorrect cannot detract from the fact that to the unaided human eye all these incorrectly described motions appear correct. The use of the Ptolemaic model together with the Copernican model improves student understanding of the motions of the heavenly bodies. 14" high x 20" long. With fully-illustrated instruction book.