Ancient Zodiacs, Star Names, and Constellations: Essays and Critiques

A Chronological History of Babylonian Astronomy by Gary D. Thompson

Copyright © 2005-2018 by Gary D. Thompson

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A Chronological History of Babylonian Astronomy


"We have to reconstruct it [Babylonian astronomy] exclusively from texts and a few schematic drawings accompanying them. No instruments relating to astronomy have been found. These texts were written on clay in cuneiform script which was used in the Near East from ca. 3000 BCE to 100 [CE]. It was completely forgotten and only deciphered in the middle of the 19th century Since then, hundreds of thousands of clay tablets have been found in archaeological excavations, mostly in present-day Iraq. Among these are a few thousand [fragmented] tablets related to astronomy. Many have been published, but more still need to be worked on. And of course an unknown number of such texts is still buried under the sands of Iraq." (Hunger, Hermann. (2011). "The relation of Babylonian astronomy to its culture and society." In: Valls-Gabaud, D. and Boksenberg, A. (Editors). The Role of Astronomy in Society and Culture. Proceedings of the IAU Symposium No. 260, 2009. (Page 62).)

The two basic methods which characterise the Babylonian approach to astral phenomena are observation and computation. Both methods are found in the earliest cuneiform texts dealing with astral phenomena (i.e., date to the Old Babylonian Period). Whilst some texts are primarily either observational or mathematical it is common for both methods to be integrated within the same text. "Observations were of far less importance than we would expect; simple schematic models for the movement of the celestial bodies were for a long time considered sufficient." (Hunger, Hermann. (2011). "The relation of Babylonian astronomy to its culture and society." In: Valls-Gabaud, D. and Boksenberg, A. (Editors). The Role of Astronomy in Society and Culture. Proceedings of the IAU Symposium No. 260, 2009. (Page 62).)

The main sources of the astral knowledge of the Babylonians from circa 1800 BCE to circa 500 BCE are the Enuma Anu Enlil omen series, the circular and tabular "astrolabes" (i.e., star calendars), the MUL.APIN series, and various observational texts (i.e., reports to the kings and the earliest astronomical diaries).

A few texts (i.e., lists) also mentioning stars and constellations date to the 3rd millennium BCE. However, Hermann Hunger points out that no principle is evident in the order of these celestial objects. "It is only in the 2nd millennium BCE that texts appear which are dealing with phenomena in the sky. In these texts we see a desire to find out how the skies are organised, and a belief that this organization can be understood and described in relatively simple ways. The use of observation is limited: while obviously one must look at the sky to be able to say something about it , schematic approaches were predominant .... An example for this are the so-called Three-stars-each texts which probably go back to between 1500 and 1000 BCE. They list, for each month of the Babylonian calendar, three constellations which are supposed to become visible in this month: one constellation to the North, one near the equator [there is no word for equator in these texts], and one to the South; it is furthermore stated that the same constellations disappear again after six months. This gives a neat scheme of 36 constellations from whose risings one could tell the time of year. However, it would not work in practice: first of all, the period of visibility is different for stars depending on their declination; it is simply incorrect to assign all of them a visibility of six months. Then, the Babylonian calendar is not easily attuned to the solar year so that helical risings of stars will not stay in the same month every year. And, just to indicate that we are far from a secure interpretation, the lists also include planets, which are subject to entirely different visibility conditions, independent of the time of the year; finally there are even variant forms of the list which have only ten constellations - instead of 12 - which makes an alignment with the months of the year impossible. The Three-stars-each lists may be seen as attempts to organise what is known about stars. At about the same time an astronomical text was compiled, called Mul-Apin (which means Plough star) after its first word. It is only attested on tablets from the 7th century [BCE] onwards, but probably goes back to the 13th century BCE." (Hunger, Hermann. (2011). "The relation of Babylonian astronomy to its culture and society." In: Valls-Gabaud, D. and Boksenberg, A. (Editors). The Role of Astronomy in Society and Culture. Proceedings of the IAU Symposium No. 260, 2009. (Pages 62-33).)

"The goal of the Babylonian scholars can best be called knowledge of the sky without any quantification whether it is a science or not." (Hunger, Hermann. (2011). "The relation of Babylonian astronomy to its culture and society." In: Valls-Gabaud, D. and Boksenberg, A. (Editors). The Role of Astronomy in Society and Culture. Proceedings of the IAU Symposium No. 260, 2009. (Page 62).) From circa 1800 BCE to circa 500 BCE the main phenomena the Babylonians sought to be proficient with were: (1) the appearance and disappearance of Venus; (2) the duration of day and night; (3) the rising and setting of the moon; and (4) planetary and stellar risings and settings. All appear within the protases of the celestial omens of the 2nd millennium period (i.e., the Enuma Anu Enlil series). The Kassite Period and the Early Period saw the completion of the omen series Enuma Anu Enlil, the introduction of the circular then tabular star calendars "the three stars each," the compilation of the MUL.APIN series, and the start of a continuing series of observational texts: Reports to the Kings, and Astronomical Diaries.

1. The Sumerian and Akkadian Period (circa 3100-2100 BCE)

Note: Dates for the Early Dynastic (Sumerian) Period vary from 3100-2330 BCE to 2900-2334 BCE. The Neo-Sumerian period is usually dated circa 2100-2000 BCE. The Akkadian Period is usually dated circa 2350-2100 BCE. [In this section I have included some of the earlier speculations of assyriologists i.e., a scheme of lunar houses. In some Sumerian texts dated circa 2500 BCE there are references to apparent stations of the moon called "houses."  In the Post Sargonic/Ur III Period the Sumerian term "house" (é) is (apparently) used to denote the celestial positioning of the moon (and to all appearances dropped during the Old Babylonian Period). Some of the earlier assyriologists proposed Pre Sargonic/Sargonic Period dates.] (Hermann Hunger ("The Cultic Calendars of the ancient Near East." in The Journal of the American Oriental Society, October-December, 1996) makes the informed and elucidating comment: "I find it misleading to mention the zodiac (and its subdivisions), which was invented around 400 B.C., in connection with the term "house" of the moon, since the meaning in the older texts is clearly not the same as in the younger. Even if the passages quoted refer to places in the sky, they could not be defined by fixed stars, because the moon is not in the same place on the same calendar date each year. Also, e-[u.sub.4]-7 seems to me to mean "house of day seven" and not "seventh house." And that could be a building on earth, as are the other "houses of the moon" mentioned.")

Simple descriptive astronomy. The Sumerians undoubtedly watched the sky and defined and named some of the constellations and planets. Bendt Alster believed astronomical observations could be discerned in Sumerian compositions dating circa 3500 BCE, which refer to the movement of the heavenly bodies and the constellations. He believed that the cyclical return of the planets, (and the sun and moon) played an important role in Mesopotamian religion. Most of the names of celestial bodies were Sumerian throughout the later periods and some of them at least must have Sumerian origins.

Some astronomical features include:

Circa 3000 BCE

Circa 2700 BCE

Circa 2600 BCE

Circa 2500 BCE

Circa 2400 BCE

Circa 2300 BCE

Circa 2250 BCE

Circa 2100 BCE

Circa 2000 BCE

2. The Old Babylonian Period (circa 2000-1600 BCE)

The first phenomenon the Babylonians sought to master were: (1) the duration of day and night; (2) the rising and setting of the moon; and (3) the appearance and disappearance of Venus. The computation of day and night appeared in two forms. An early form appears in the protases of the Enuma Anu Enlil omen series and also in the circular astrolabes.

Circa 1800 BCE

Circa 1750 BCE

Circa 1500 BCE

3. The Kassite Period (circa 1570-1160 BCE)

Within the protases of the celestial omens of the period (i.e., Enuma Anu Enlil) appear: (1) planetary and stellar risings and settings, (2) daylight lengths, (3) lunar visibility, and the appearance and disappearance of Venus. The moon was also divided into 4 equal sectors for omen purposes; representing the 4 countries Akkad, Subartu, Elam, and Amurru. As Ernst Weidner noted, Babylonian omen astrology is primarily geographical. The four terrestrial regions named in a large percentage of the celestial omens were not mere labels given to arbitrarily derived astronomical divisions, they were real places whose names represented historical, political and socio-religious relationships with Babylonia. These relationships and the impressions they leave behind in the collective memory become the basis from which many of the omen apodoses are constructed.

The use of heliacally rising stars along the eastern horizon and the introduction of Astrolabe texts.

Between 1400-900 BCE the following things happened:

Circa 1400 BCE

Circa 1350 BCE

Circa 1250 BCE

Circa 1200 BCE

Circa 1150 BCE

Circa 1100 BCE

4. The Late Assyrian Period (circa 1000-600 BCE)

Note: The Late Assyrian Period is also dated circa 900-600 BCE. This would place MUL.APIN data in the Middle Assyrian Period.

The period from 750-350 BCE saw refinements in the development of non-mathematical astronomy including the introduction of (1) Astronomical Diaries, (2) Almanacs, and (3) the Goal Year Texts.

The main astronomical achievements of this period are:

Circa 1000 BCE

Circa 800 BCE

Circa 750 BCE

Circa 700 BCE

The series MUL.APIN and the related texts show significant astronomical advances, namely:

Accurate period relations are not to be found in the early texts. For example, the MUL.APIN compendium does not give a single period for the sun, moon or planets, apart from the schematic year of 12 months of 30 days each. The situation changed rapidly during the Persian period.

In the middle of the 8th century BCE astronomy seems to have received a new impetus, as shown by:

Circa 650 BCE

5. The Neo-Babylonian (Chaldean) Period (626-539 BCE)

Once Babylon became independent of Assyrian rule in the 7th-century BCE, the focus of how astronomy was done changed. Unlike the astronomy of the Neo-Assyrian Empire, where scholars were employed in many cities across the region, almost all astronomy from the Late Babylonian Period originates from the city of Babylon.

Note: Conquest of Assyria by the Chaldeans (inhabitants of māt Kaldu) in 609 BCE - fall of Babylon to the Medes in 539 BCE.

Zodiacal astronomy.

Main astronomical features:

Circa 630 BCE

Circa 600 BCE

6. The Persian (Achaemenid) Period (539-331 BCE)

Note: Persian (Achaemenid) Period (535-331 BCE; fall of Babylon to the Medes - fall of Babylon to the Macedonians).

The astronomy of the Persian (Achaemenid) and Seleucid (Hellenistic) periods has the following typical features:

The most important achievements of this period are:

The six lunar phenomena that were regularly observed and recorded were:

(1. Observed just after New Moon on the evening of first visibility of the crescent.):

(2. Observed just before and after Full Moon.):

(3. Observed on the day of last visibility of the moon in the morning.):

Circa 540 BCE

Circa 500 BCE

Circa 430 BCE

Circa 400 BCE

7. Macedonian Period (331-circa 275 BCE)

Note: Macedonian Period (331-circa 275 BCE; fall of Babylon to the Macedonians - end of era of the Diadochi). [Era of the Diadochi (first generation of important Macedonian military and political (administrators) successors after the death of Alexander) is taken to be 323-circa 275 BCE.]

Mathematical astronomy. The largest and most highly developed part of the theoretical astronomy of the Macedonian period and Seleucid period is devoted to the computation of the new moons.

Circa 320 BCE

Circa 300 BCE

8. Seleucid (Hellenistic) Period (275 BCE - 116 CE)

Note: Seleucid Period (275 BCE - 116 CE; end of era of the Diadochi - Roman conquest of Mesopotamia).

All classes of Seleucid astronomical texts contain at least some predictions.


Circa 200 BCE

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