The Farnese Atlas is a 2nd-century Roman marble copy of aHellenistic sculpture of Atlas kneeling with the celestial spheres, not a globe, weighing heavily on his shoulders. It is the oldest extant statue of the Titan of Greek mythology, who is represented in earlier vase-painting, and more importantly, the oldest known representation of the celestial sphere. The sculpture is at the National Archaeological Museum of Naples, in Italy. It stands tall, and the sphere is 65 cm in diameter. The name Farnese Atlas reflects its acquisition by Cardinal Alessandro Farnese in the early 16th century, and its subsequent exhibition in the Villa Farnese. Atlas labors under the weight because he had been sentenced by Zeus to hold upthe sky. The sphere shows a depiction of the night sky as seen from outside the outermost celestial sphere, with low reliefs depicting 41 of the 48 classical Greek constellations distinguished by Ptolemy, including; Aries the ram, Cygnus the swan and Hercules the hero. The Farnese Atlas is the oldest surviving pictorial record of Western constellations. It dates to Roman times, around AD 150, but has long been presumed to represent constellations mapped in earlier Greek work.
Dating the original
In 2005, at a meeting of the American Astronomical Society in San Diego, California, Dr. Bradley E. Schaefer, a professor of physics at Louisiana State University, presented a widely reported analysis 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. 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 – leading to the conclusion that the statue is based on the star catalog. However, because the globe contains no actual stars, and because the circles on the globe are drawn inexactly and ambiguously by a sculptor copying the Hellenistic model rather than by a modern astronomer, the dating of the globe is still uncertain and its source or sources remain controversial; Schaefer's conclusions have been strongly contested most particularly on the ground that regardless of the globe's date the constellations on it show large disagreements with the only existing work by Hipparchus.
