The temple astronomers of Babylon had observed the skies for centuries and had recorded their observations in astronomical diaries, and other catalogues. Their predictions are almost accurate to this day.
In fact, the Assyrians and Babylonians regarded lunar eclipses as evil omens. They believed that eclipses were directed against their kings. This was one reason why they studied more about the Moon. They studied the length of the synodic month, the period between two full moons. Their observations were almost error free. Using these data on the synodic month, the Babylonian astronomers were able to predict lunar eclipses and solar eclipses later.
They also recorded the 18-year Saros cycle of lunar eclipses. A Saros cycle is the period of 223 synodic months-18 years and 11.3 days- after which lunar and solar eclipses repeat themselves. The predictability of the lunar eclipse made it possible for the Babylonians to appoint substitute kings who would bear the burden of the wrath of the gods.
Picture Credit : Google