How old are asterisms?

Connect the dots!

When I looked at the sky as a child, I always wondered how people could distinguish constellations. There were sooo many stars! Much later, now more familiar with the celestial images, the next question came up: why would people see particular constellations as a bull or a water-bearing man? The constellations bore little resemblance to recognizable human or animal forms—as if the sky refused to pose for a photograph!

Why would one see a Crab in that particular part of the sky, or a climbing Capricorn? Why would some constellations move bottom first (Taurus) and others head first?

My next problem, already deep into astrology, was: why would so many cultures associate the same animal with the same mass of stars? But there was a more pressing question. Even those cultures that have different symbols still use the same portions of the sky to group their constellations. Why? They could have grouped them very differently. Why, for example, were the stars that we see today in Orion’s club not considered part of a constellation with some stars of Taurus, like Alheka? They are rather close together! Or why was Elnath considered part of Taurus and not of Auriga?

This leads us to two important issues:

Many distant cultures used the same figures.
Even if they used other figures, those figures occupied the same portions of the sky and included the same stars.

Let’s differentiate between asterisms, meaning the extension of certain constellations and the grouping of stars into figures. Astronomy uses sketches (asterisms) for them, as shown here for Draco and Taurus —basically the stars that connect the (fixed star) dots.

The figure of an animal, object, or human form is what becomes associated with the asterism, as shown here, again, for Draco and the Bull.

We can find proof of profound ancient astronomical knowledge all over the world and in almost every culture. The Indian Mahabharata and the Ramayana, the Babylonian Enuma Elish, and the Bible, to name just a few, all contain astronomical information. As Harvard professors Giorgio de Santillana and Hertha von Dechend have shown in Hamlet’s Mill, mythologies from all over the world speak about the precession of the equinoxes. In other words, these myths tell the story of very long cycles of time—something that requires advanced astronomical understanding. This knowledge, embedded in colourful stories transmitted from one generation to the next, was hidden in plain sight but accessible only to those who had the proper key to understand it.

This brings us to an important question:

Have constellations always been associated with the same asterisms?

Apparently, yes. While the names and figures associated with the asterisms have changed over time, the asterisms themselves have remained the same. Asterisms follow a precise order in the sky. Manilius, Ptolemy, and many other ancient astronomers described the positions of the constellations—what lies to the left or right of a particular celestial figure—essentially what we call today sky maps. However, these sky maps seem to be much older than we have so far acknowledged. Researchers such as Papke on the Babylonian Gilgamesh myth, among others, claim that ancient cosmologies—the so-called “hero’s journey”—actually describe astronomical phenomena.

Göbekli Tepe in Turkey is one of the most ancient archaeological sites ever discovered and dated. It is at least 10,000 years old. Its many stone circles contain standing T-shaped pillars, some of which are covered with animal engravings. Göbekli Tepe appears to have been an ancient observatory, and many researchers assume that the figures on these pillars indicate constellations, especially since one of them clearly depicts a scorpion in one corner (not shown).

In his book Prehistory Decoded, Martin Sweatman discusses in detail the famous T-pillar known as the Vulture Stone at Göbekli Tepe, carbon-dated to around 10,000 BCE.

He proposes that the figures carved on the column correspond to specific constellations. Although these figures do not resemble the familiar zodiacal symbols we use today, Sweatman argues that the animal depictions share precise outlines matching asterisms still recognized in modern astronomy.

According to his interpretation, constellations such as Cancer, Gemini, and Leo were already defined by the same star patterns, though they may have been represented by different animals or symbolic forms. In other words, the stars themselves were connected in much the same way as we do now—like dots forming a picture—while the associated myths and figures evolved over time.

Essentially, Sweatman suggests that while the names and shapes of constellations may have changed, their spatial relationships remained constant: Orion, for instance, still lies below Taurus. More importantly, the underlying asterisms appear to have endured largely unchanged.

Thus, even if we do not immediately recognize the vulture as a zodiacal figure, we may still discern the same star pattern beneath it—connect the dots, and the familiar structure emerges once more.

Sweatman further noticed that certain symbols carved above the animal figures on the Vulture Stone at Göbekli Tepe resemble handbags. Similar motifs have been identified across many other cultures and epochs. In the Pergamon Museum in Berlin, for instance, I found dozens of Mesopotamian reliefs depict figures carrying comparable handbag-like objects, like the one shown in the image.

These motifs appear repeatedly in Sumerian, Assyrian, and Persian artifacts, suggesting a long-lasting symbolic tradition.

Sweatman proposes that these “handbags” may represent the cardinal points and hence mark the equinoxes and the summer solstice. If this interpretation is correct, the implications would be significant. As a reader in statistical mechanics at the University of Edinburgh, Sweatman applies his background in statistical analysis to archaeology. He argues that if even one constellation depicted on the stone could be identified with statistical certainty, then the others might also be matched, since the underlying asterisms would align in predictable ways.

I should add here that the constellations (or their asterism) do not really change over the millennia as per se, but their orientation does. Depending on their declination (a topic I will be discussing extensively in my upcoming book) they would appear to rotate slightly and move up or down in relation to the horizon of a given place. This inclination could also be used to time the sky. This is why recognizing the vernal equinox among these patterns could provide a means to date the construction of Göbekli Tepe, offering a temporal anchor for its astronomical context.

The broader impression, according to Sweatman and many other authors, is that the site was built for future generations—perhaps as a message or record intended to endure through time. Understanding when it was built, and which constellations it points to, may bring us closer to understanding why it was built.

For now, my takeaway from this book is that the knowledge of the asterisms of the constellations might be far older than the shapes (later) assigned to them. Of course, the question of the why remains the elephant in the room.

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