MUL.APIN ("The Plough Star") is the oldest surviving systematic astronomical treatise. Probably compiled between c.1200 and c.1000 BC from even older observational traditions, it was transmitted on cuneiform tablets, of which copies from the 7th century BC survive, found in Ashurbanipal's library in Nineveh. It contains catalogues of 66 stars and constellations organized into three celestial paths (of Anu, Enlil, and Ea), the dates of heliacal rising and setting of the planets, the durations of daylight throughout the year, and rules for computing intercalations in the lunar calendar. It establishes the zodiac as a celestial reference band. Babylonian astronomy, developed over more than a millennium before Hipparchus and without connection to the Greek tradition until the Hellenistic period, is the true first link in the observational chain that reaches Newton.