Astronomy Tablet, 19th-18th century BCE

Based on regular sightings made in the 19th and 18th centuries BCE in the city of Kish, this clay cuneiform tablet is a record of the rising and setting of Venus, the so-called Star of Ishtar. These and other astronomical observations were used to predict the future and, as markers of time, are accurate enough for historians to be able to establish the dates of early Babylonian kings of the second millennium.

Mesopotamia- The Mighty Kings, Alexandria, Virginia- Time-Life Books, 1995, p. 16.