Astronomical Diary

Definition

An Astronomical Diary (Akkadian naṣāru ša ginê, "regular watching") is the genre of non-mathematical Late Babylonian observational text recording night-by-night celestial and terrestrial phenomena: the moon's position relative to Normal Stars, the Lunar Six time-intervals, planetary appearances and stations, eclipses, meteors and halos, weather, commodity-prices, river-level, and contemporary historical events. The standard critical edition is Sachs & Hunger, *Astronomical Diaries and Related Texts from Babylonia* (1988-2006), in which the diaries are arranged in successive volumes by Seleucid-era date.

In Tradition

Rochberg and Brown both treat the Astronomical Diaries as the foundational empirical data-class of Late Babylonian astronomy: the genre from which the predictive infrastructure of the Goal-Year Texts, Almanacs, and ACT mathematical-astronomy procedure-texts derives. Brown argues that the Diaries, Eclipse Records, and Planet Records together supply the dated time-and-location data for both directly and indirectly ominous phenomena, supporting the PCP-Paradigm prediction project.

In Practice

For the student of Late Babylonian astronomy, the Astronomical Diary names the longest sustained scientific observation programme of antiquity — a centuries-long, multi-scribe, dated night-by-night record. The earliest extant Diary dates to 652 BCE (the moon described as "bright and high" on the first day of month I; the 15th-day full-moon syzygy described as "one god was seen with another"), with the genre continuing into the first century BCE. Lunar Six values were systematically noted and, from at least 568 BCE, predicted-and-filled-in when weather blocked observation. Each Diary line carries a fixed format: date, lunar interval, Normal Star reference for the moon, then planet-by-planet position records, with terrestrial-economic notes (commodity-prices in Babylon, Euphrates river-level) appended. The compilations reach back to the Nabonassar era (747 BCE) and supplied Ptolemy's eclipse-record archive through Hipparchus.

Historical Origin

Earliest extant: -652 (Sachs-Hunger Diary No. -651), with a small number of seventh-and-sixth-century texts (-651, -567); continuous from the late fourth century BCE through the late first century BCE. Modern critical treatments: Rochberg, *The Heavenly Writing* (2004), pp. 161, 165, 169; Brown, *Mesopotamian Planetary Astronomy-Astrology* (2000), Ch. 4 §4.2.1 pp. 198, 201; Sachs & Hunger, *Astronomical Diaries and Related Texts from Babylonia* (1988-2006).

Further Reading

• Francesca Rochberg, The Heavenly Writing: Divination, Horoscopy, and Astronomy in Mesopotamian Culture
• David Brown, Mesopotamian Planetary Astronomy-Astrology
• Abraham Sachs & Hermann Hunger, Astronomical Diaries and Related Texts from Babylonia