The world's oldest known star map, linked to the ancient Greek astronomer Hipparchus, has been rediscovered by researchers at the SLAC National Accelerator Laboratory. This star map, found beneath layers of medieval writings in a palimpsest, showcases ancient astronomical texts that were previously obscured. Hipparchus is credited with creating one of the first organized catalogs of the night sky, a revolutionary approach that transformed stars from mere symbols into measurable points in the universe. The discovery was made possible through advanced X-ray imaging technology, which revealed traces of the erased inscriptions. While the fragments do not confirm a complete ancient star atlas, they represent the oldest systematic catalog of stars available today. This finding is significant as it provides rare evidence of early astronomical practices and highlights the accidental preservation of scientific history through the reuse of expensive parchment. The manuscript connects modern scholars to the ancient quest for understanding the cosmos, initiated over two thousand years ago.