Farnese Atlas

The statue is dated around CE 150, during the Roman Empire and after the composition of the Almagest by Claudius Ptolemy, but the celestial globe has long been presumed to represent constellations mapped in earlier Hellenistic astrology, particularly in the work of Hipparchus in the 2nd century BCE.

The sphere shows a depiction of the night sky as seen from outside the outermost celestial sphere, with low reliefs depicting 41 (some sources say 42) of the 48 classical Greek constellations distinguished by Ptolemy, including Aries the ram, Cygnus the swan and Hercules the hero.

In 2005, at a meeting of the American Astronomical Society in San Diego, California, Bradley E. Schaefer, a professor of physics at Louisiana State University, presented a widely reported analysis[3] concluding that the text of Hipparchus' long lost star catalog may have been the inspiration for the representation of the constellations on the globe, thereby reviving and expanding an earlier proposal by Georg Thiele (1898).

The constellations are fairly detailed and Schaefer regards them as scientifically accurate given the period of the globe's creation, implying that it was modeled after a scholarly work.

His statistical analysis concludes that the positions of these constellations are consistent with where they would have appeared in the time of Hipparchus (129 BCE) – leading to the conclusion that the statue is based on the star catalog.