Astronomers like Hipparchus (c. 190 – c. 120 BC) built upon the measurements of the Babylonian astronomers before him, to measure the precession of the <answer>Earth</answer>. Pliny reports that Hipparchus produced the first systematic star catalog after he observed a new star (it is uncertain whether this was a nova or a comet) and wished to preserve astronomical record of the stars, so that other new stars could be discovered. It has recently been claimed that a celestial globe based on Hipparchus's star catalog sits atop the broad shoulders of a large 2nd-century Roman statue known as the Farnese Atlas. Another astronomer, Aristarchos of Samos developed a heliocentric system.
Hipparchus measured the precession of what?
Earth