Importantly, it does not match the dates of other ancient sky descriptions, including both Aratus's and Eudoxus's Phaenomena and the sky catalog published in the Almagest by Claudius Ptolemy. This date closely matches that of Hipparchus's catalog. ![]() ![]() Schaefer says the figures' positions relative to the meridians and the equator point to the year 125 b.c., with an error of 55 years either way. Precession - the slow shift of Earth's axis that Hipparchus himself discovered - provides a way to date the globe. He found the average placement of these fell within 1.5° of their correct locations, indicating the globe was laid out skillfully. ![]() Schaefer photographed the statue, which is about 7 feet (2 meters) high, from all sides and used photogrammetry to derive the positions of 70 well-defined points on the globe. The globe, 26 inches (65 centimeters) in diameter, shows 41 Greek constellation figures in raised relief, plus lines marking the celestial equator, the meridians of the solstices and equinoxes, and the ecliptic and tropics - but no stars.
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