MUL.APIN — Safekipedia Adventurer

MUL.APIN (𒀯𒀳) is the name of an ancient Babylonian book about stars and the sky. It is special because it mixes two kinds of knowledge: astronomy, which is the study of stars and planets, and astrology, which is about how people thought stars could affect events on Earth. It was probably written around the year 1000 BCE, making it over 3,000 years old!

One of the two clay tablets on which the text is written. This exemplar shows that the tablet is unusually huge (as large as a sheet of paper) and the text is written in two columns.

The book lists 66 stars and groups of stars called constellations. It tells us when these stars rose, set, and reached their highest points in the sky during the year. This helped ancient people make maps of the stars, which they used to track seasons and important days.

We know about MUL.APIN from a copy made in the 7th century BCE. This copy is written on clay tablets and is named after its first constellation, called MUL APIN, meaning "The Plough." This group of stars is thought to be the same as what we now call the constellation Cassiopeia. Some experts think it might only refer to Cassiopeia, while others believe it also includes stars from Andromeda and Triangulum. This ancient book shows us how early people saw and understood the night sky.

Date

The earliest known copy of the text MUL.APIN was made in 686 BCE. Most scholars think it was first written around 1000 BCE.

Scientists studied the stars mentioned in the text. They believe the information matches what would have been seen around the year 1370 BCE in the area of Assur. This helps us understand when the text was likely created.

Parts

The Babylonian globe (no matter whether or not it existed physically) would have been divided in three paths of the gods Ea (south), Anu (±17° around the equator) and Enlil (northern cap, all declinations >17°). These three gods have their "seats" among the stars, represented by the constellations Cancer and Iku (Pegasus).

The MUL.APIN text is split into two tablets, with a third tablet that has not been found. Tablet 1 helps us understand the Babylonian star map. It shows how the constellations are connected to each other and to the calendar. Even though the Babylonian calendar sometimes added an extra month, MUL.APIN uses a simpler year of 12 months, each with 30 days.

Tablet 2 is very useful for learning about how Babylonian astrologers watched the sun, moon, and planets. It has details about the paths of these celestial bodies, which stars appear on special dates, and simple ways to track the moon and the changing lengths of day and night during the year. It also talks about some early ideas and predictions about the stars.

Tablet I – Description of the static sky
List 1	I i 1	to	I ii 35	catalog of asterisms (inventory of the sky)
List 2	I ii 36	to	I iii 12	dates of heliacal rises in the Babylonian calendar
List 3	I iii 13	to	I iii 33	simultaneous rises and settings
List 4	I iii 34	to	I iii 48	time intervals between heliacal risings
List 5	I iv I	to	I iv 30	ziqpu-asterisms
List 6	I iv 31	to	I iv 39	asterisms in the path of the Moon

Tablet II – Changes in the sky
List 1	II i 1	to	II i 8	motion of planets in the lunar path
List 2	II i 9	to	II i 24	determining cardinal points of the year
List 3	II i 25–37	and	II i 68–71	heliacal risings and wind direction
List 4	II i 38	to	II i 67	planets – visibilities
List 5	II ii 1	to	II ii 20	intercalary rules
List 6	II ii 21	to	II ii 42	shadow lengths of the sundial
List 7	II ii 43	to	II iii 15	water clock
List 8	II iii 16	to	II iv 12	omens

Function of the text

Map of the Babylonian Sky. Celestial equator divided in 12 equal parts (ideal months), constellations as polygons because only estimates of their position can be derived from the preserved data. Pingree's identification of constellations. Path of Anu marked in grey, path of the moon brighter than other constellations. Similar maps have been published in Hoffmann (2017).

MUL.APIN is the oldest known book of star knowledge from ancient Babylon. It lists stars and constellations to help people see patterns in the night sky. The text shows when stars appear, disappear, and reach their highest points, which helped create a calendar.

The book uses special days and months to explain where stars are in the sky. This helped Babylonian astronomers draw maps of the sky and learn how the Moon and Sun move during the year. By watching the stars, they could find important dates, even if some details were not exact.


intercalary rules in MUL.APIN
intercalation with heliacal risings
II Gap A 10	to	II Gap A 11	heliacal rise of the Pleiades
II Gap A 12	to	II Gap A 16	heliacal rise of Sirius
II Gap A 17	to	II Gap A 18	heliacal rise of Arcturus
intercalation with the Moon
II ii 1	to	II ii 2	plejadenschaltregel (i.e. Pleiades and the Moon)
II ii 3	to	II ii 4	intercalary rule for Sirius (i.e. Sirius and the Moon)
II ii 9	to	II ii 17	algorithm to compute correction and deduction of the rule to intercalate all three years

Accuracy of the numbers

The Babylonian astronomers who wrote MUL.APIN had trouble when they watched the stars. They could only know when a star or constellation appeared by looking at different days and comparing notes. Sometimes clouds made it hard to see, and different people might see things differently. Because of these problems, they could only guess when a star rose or set within a few days.

In MUL.APIN, the information about when stars and constellations appeared is given in numbers that are multiples of five. This probably shows how unsure they were about their measurements. When trying to find out exactly where these constellations were in the sky, modern scientists can only estimate their positions with some error, similar to the size of the constellation itself.

Path of the Moon – the Pre-Zodiac

These pictures show how the Moon travels across the sky. They use ideas from old times to help us learn about how people long ago thought about the stars and the Moon.

No.	MUL.APIN name	Translation	Constellation (IAU)	associated god according to List 1
1	MUL.MUL	Many Stars (or: Star Cluster)	Pleiades (Taurus)	Anu
2	GU₄.AN.NA	Bull of Heaven	Taurus	Anu
3	SIPA.AN.NA	True Shepherd of Anu	Orion	Anu
4	ŠU.GI	Old Man (Enmešarra, the last of Enlil's primeval ancestors)	Perseus	Enlil
5	GAM	Crook	Auriga	Enlil
6	MAŠ.TAB.BA.GAL.GAL	Great Twins (Lugal-irra and Meslamta-ea, a pair of netherworld gods)	Gemini (north of ecliptic)	Enlil
7	AL.LUL	Crab	Cancer	Enlil
8	UR.GU.LA	Lion	Leo	Enlil
9	AB.SIN	Furrow	Virgo (north of Spica)	Šala
10	RIN	Balance	Libra and the part of Virgo south of Spica	Anu
11	GIR.TAB	Scorpion	Scorpius (maybe plus southern parts of Ophiuchus)	Ea
12	PA.BIL.SAG	Pabilsang (city god of Larak, who was identified with Ninurta, particularly in his role as the husband of the healing-goddess Gula)	Sagittarius	Ea
13	SUḪUR.MEŠ	Goat-Fish	Capricornus	Ea
14	GU.LA	The Great One (a common by-name of the god Ea/Enki)	Aquarius	Ea
15	KUN^MUŠ (ša) SIM.MAḪ	Tails of the Great Swallow	Pisces	Anu/Ea
16	^DingirAnunitu	Goddess Anunitu	the eastern one of the two fishes in Pisces plus parts of Andromeda (β And)	Anu
17	^LUHUN.GA	Hired Man (or: Loan Worker) (Dumuzi, the mythical lover of Inanna/Ištar who is imagined as a shepherd)	Aries and Triangulum	Anu