How did ancient people calculate eclipses?

Centuries go by and eventually enough of a pattern has built up that early civilizations are able to predict when these crazy events might occur. ... about 700 BC, Mesopotamians were able to determine the length of a Saros Cycle—the interval between when the Moon, Earth, and Sun line up for an eclipse. read more

Lunar eclipse were especially easy to calculate because of the vast area covered by the Earth's shadow on the Moon. Solar eclipses, however, required much greater finesse and knowledge. read more

Ancient Babylonians living almost 4,000 years ago could have predicted Monday's total solar eclipse. In fact the ancient Babylonians were the fathers of modern astronomy. They could track and predict the relative movements of the sun and moon, and even those of the Solar System planets that they recognized, Venus and Mercury. read more

Its 223 divisions correspond to months in the Saros cycle, another ancient calendar system—this one an 18-year cycle—for tracking eclipses. Of these divisions, researchers had previously identified 16 that were marked with glyphs, or sets of characters, indicating solar and lunar eclipses. The team increased that number by two to 18. read more