Babylonian star catalogues facts for kids

This ancient list from Uruk (Iraq), made between 320 and 150 BC, shows constellations, how many stars they have, and their distance to the next constellation.

Ancient people in Babylonia (a powerful kingdom in Mesopotamia, which is modern-day Iraq) were very good at watching the sky. They collected many years of observations about stars and planets. These observations became known as Babylonian star catalogues.

These special lists were written on clay tablets using a writing system called cuneiform. They included names of star groups (which we call constellations), individual stars, and planets. It's thought that these constellations came from different places. The very first catalogue, called Three Stars Each, even mentioned stars from places like Akkad, Amurru, and Elam.

Some people think these Babylonian constellations first came from the ancient land of Sumer. Others believe they might have come from Elam. There's also a possible link to symbols found on special boundary stones called kudurru. However, it's not fully clear if these symbols were truly about stars or just general symbols.

After the Three Stars Each catalogue, another important list appeared called MUL.APIN. This name comes from its first constellation, ^MULAPIN, which means "the Plough." Today, we know this as the Triangulum constellation plus a star called Gamma Andromedae. The MUL.APIN listed about 17 or 18 constellations that were part of the zodiac. Later, this list was shortened to 12 zodiac constellations. These 12 were then used by the Egyptians and Greeks, and we still use them today!

Three Stars Each Catalogue

The first official collections of star lists were called Three Stars Each. They started appearing around 1200 BC. These texts divided the sky into three parts:

• The northern part belonged to the god Enlil.
• The middle part (the equator) belonged to the god Anu.
• The southern part belonged to the god Enki.

The dividing lines were at 17 degrees North and South. This meant the Sun spent exactly three months in each section of the sky. The Three Stars Each catalogues listed 36 stars, with three stars for each month of the year.

In these lists, the special symbol for "constellation" or "star" was MUL (𒀯). This symbol looked like three stars. For example, the Pleiades star cluster was called "star of stars" or "star cluster," written as MUL.MUL (𒀯𒀯).

MUL.APIN: The Plough

The second major collection of stars in Babylonian astronomy was the MUL.APIN. This was a set of two clay tablets. Its name comes from its first line, which mentions the constellation ^MULAPIN "The Plough." This constellation is known today as Triangulum and Gamma Andromedae.

The MUL.APIN list came from the earlier Three Stars Each list. It was updated around 1000 BC using more accurate observations. This new list included more constellations, especially those that are always visible in the sky (circumpolar ones) and more of the zodiac constellations.

Babylonian star catalogues later influenced Greek astronomy around the 4th century BC, thanks to scholars like Eudoxus of Cnidus. Some of the constellation names we use today can be traced back to these Babylonian sources through Greek astronomy.

Some of the oldest constellations marked the four important points of the year during the Middle Bronze Age. These included:

• Taurus "The Bull," from ^MULGU₄.AN.NA "The Steer of Heaven." This marked the start of spring (March equinox).
• Leo "The Lion," from ^MULUR.GU.LA "The Lion." This marked the start of summer (summer solstice).
• Scorpius "The Scorpion," from ^MULGIR.TAB "The Scorpion." This marked the start of autumn (September equinox).
• Capricornus "Goat-Horned," from ^MULSUḪUR.MAŠ "The Goat-Fish." This marked the start of winter (winter solstice). This creature was a mythological hybrid often seen on ancient boundary stones.

Other constellation names also have roots in the Bronze Age. These include Gemini "The Twins," from ^MULMAŠ.TAB.BA.GAL.GAL "The Great Twins," and Cancer "The Crayfish," from ^MULAL.LUL "The Crayfish."

The MUL.APIN tablets contained a lot of information, such as:

• A list of 71 stars and constellations from the "Three Ways" tradition.
• Dates when stars first appeared in the sky at sunrise (called heliacal risings).
• Pairs of constellations that rose and set at the same time.
• How long it took between certain star risings.
• Pairs of constellations that were at their highest point (zenith) and lowest point (horizon) at the same time.
• The path of the Moon and planets.
• A calendar based on the Sun.
• Information about planets and how long they were hidden by the Sun.
• Star risings and planet positions used to predict weather and adjust the calendar.
• How to tell time using the shadow of a gnomon (a simple sundial).
• The length of night watches throughout the year.
• Omens (predictions) related to stars, planets, comets, and winds.

Zodiac Constellations

The path of the Moon described in the MUL.APIN included 17 or 18 special points. These points were the direct ancestors of the 12-sign zodiac we know today. The list started with the Pleiades star cluster. This shows that in the Early to Middle Bronze Age, the Sun was near the Pleiades (in Taurus) during the spring equinox, not yet in Aries.

The "Tail" and the "Great Swallow" (items 15 and 16 in the table) might have been seen as one constellation, "The Tail of the Swallow" (Pisces). This is why there's some debate about whether there were 17 or 18 constellations in the Babylonian "zodiac." All the constellations of our modern 12-sign zodiac were present among them. Most had names that clearly match, though some reached Greek astronomy with slightly changed names. For example, "Furrow" became Virgo, "Pabilsag" became Sagittarius, "Great One" became Aquarius, "Swallow Tail" became Pisces, and "Farm Worker" was later called Aries.

The constellation Virgo and its bright star Spica have Babylonian roots. The MUL.APIN linked "Absin" (The Furrow) to the Sumerian goddess Shala. On ancient boundary stones from the Kassites, Shala is often shown holding a stalk of grain. Sagittarius was linked to Pabilsag, a Sumerian god. Another name for this constellation was "The Soldier."

Aquarius, "The Water-Pourer," represented Ea, a water god. In the MUL.APIN, he was called "The Great One." This constellation held the winter solstice in the Early Bronze Age. In Greek astronomy, Aquarius became simply a vase pouring water down to the constellation Piscis Austrinus. The name for Aquarius in the Hindu zodiac is kumbha, meaning "water-pitcher," which shows that the zodiac traveled to India through Greek ideas.

The constellation Pisces as we know it today is the youngest of the zodiac constellations. The "Swallow" in Babylonian astronomy included the western fish of Pisces, but it was larger and also included parts of Pegasus. The square shape of Pegasus was known as the "field" constellation. The northern fish of Pisces and part of Andromeda represented the goddess Anunitum, "Lady of the Heaven." Later Babylonian texts also mention "The Fish-Cord." It's not clear how the "Farm Worker" from the MUL.APIN became Aries "The Ram" in Greek tradition. It might have been a play on words or a misunderstanding.

Around 500 BC, Babylonian astronomical texts started describing the positions of the Sun, Moon, and planets using 12 equally spaced "signs." Each sign was linked to a zodiac constellation and divided into 30 degrees. This standardized zodiac was fixed to the stars and totaled 360 degrees.

See also

• Babylonian astrology
• Babylonian calendar
• Constellation
• Enuma Anu Enlil
• Triple deity
• Venus tablet of Ammisaduqa