G06: Mesopotamia: Astronomy & Calendar

The Babylonians were famous in antiquity for their scientific prowess. They were expert diviners and were especially proud of their ability to interpret the will of the gods by reading the entrails of sacrificial sheep. Their fascination with the firmament and their advanced knowledge of its workings was acknowledged, and their observations, which were recorded over centuries, were used by Greek astronomers in Late Antiquity. Indeed, astronomical, and astrological, practice and lore are part of Babylon’s enduring legacy, elements of which are with us even today. Undoubtedly, the most famous is the zodiac circle of twelve signs, most of which still bear names related to their Babylonian origins.

The Sumerians of Babylonia were probably the first people to make a calendar. They used the phases of the Moon, counting 12 lunar months as a year. To make up for the difference between this year and the solar year of the seasons, they inserted an extra month in the calendar about every four years.