Astronomical Diaries and Related Texts from Babylonia: Volume VI: Goal Year Texts

This volume presents an edition of cuneiform tablets with lunar and planetary data from the 3rd century to the 1st century B.C. Most of these data are observations, in all likelihood excerpted from Astronomical Diaries of the kind published in Vols. I to III. Planetary phenomena reoccur after a certain number of years on almost the same calendar date within the Babylonian year. The number of years is quite easy to calculate if one has observations of planetary phenomena such as those in the Diaries; this period is different for each planet. The so-called goal-year texts collect observations one period earlier than the year for which the text is intended. This enables quite good predictions of the planet positions on particular calendar dates. The texts were probably also used by Babylonian astronomers to investigate periodically recurring phenomena, in order to discover means of computing them in advance.