In modern scholarship, Babylonian astral science (astronomy, astrology, celestial divination) is commonly perceived as being oriented towards the future. In this paper, we argue that Babylonian scholars also used astronomical prediction to study, interpret, order, and reconstruct the past. In particular, developments in astronomical and astrological prediction during the first millennium BCE engendered a new approach to historiography. This approach involved retro-calculating phenomena of the ancient sky in order to explain events that had happened in those distant times. By backwardly projecting predictive schemes on historical data found in received texts, these scholars developed a new historiographic method based on archival research and astral science.
