
What you see here is a circular clay tablet, discovered 150 years ago by Sir Austen Henry Layard, one of the luckiest and most enterprising of Victorian archaeologists. It was recovered from a brief dig at the site of Nineveh, capital of ancient Assyria, in what is now Iraq. If you would ever like to find it yourself, it is held in the British Museum, Registration number K.8538.
Description
Part of a circular clay tablet with depictions of constellations (planisphere); the reverse is uninscribed; restored from fragments and incomplete; partly accidentally vitrified in antiquity during the destruction of the place where it was found.
Inscriptions
Inscription Type: inscription
Inscription Script: cuneiform
Inscription Language: Babylonian
Dimensions
Diameter: 14.1 centimetres (maximum)
Thickness: 3.2 centimetres
Condition
Heavily restored with plaster.
Curator’s comments
For comment on the interpretation of the text and identification of the constellations see Koch 1989. Celestial planisphere; in this stylised map the sky has been divided into eight sections. It represents the night sky of 3-4 January 650 BC over Nineveh. The rectangular shape at the top has been identified as the constellation known today as Gemini and the stars contained with an oval shape are the Pleiades. The two triangles in the lower right mark the bright stars of Pegasus.
The object is, without doubt, fascinating in its own right. Any archaeologist worth her salt can explain to you the importance of the Library of Ashurbanipal, and recount some of Layard’s almost absurdly important discoveries. But this article is not about this object per se, nor about the Library of Ashurbanipal, nor even about Layard.
This article is about a controversy inspired by archaeological data, and more broadly about how Science works, and how the human race as a whole acquires knowledge…and fills in the emptiness of what we do not and cannot know with the imagination, for good or ill.
I’m posting this article for two reasons.
1. I find the transmission of knowledge and ideas from the past inherently interesting. Clay tablets are a fascinating pool of information from the ancient Near East, and hundreds of people can spend their lives studying these relics without being able to translate and collate all the information they have to offer.
2. It is important once in a while to remind everyone that Science is not Religion. There is no doctrine, no dogma, no universal truth which is universally accepted, while all other views are damned as heresy.
Science is about highly intelligent people putting forward their ideas and trying to prove them. Nothing more, nothing less. It follows as a corollary that people with different ideas will do their best to prove themselves right and others wrong.
People in different disciplines can come into direct conflict and argue vociferously about whose authority takes precedence. People in the same discipline may actually develop personal antipathy and even come to blows about their differing theories and worldviews.
Furthermore, there is no way to bar anyone and everyone from participating in the construction of human knowledge. We develop some rough guidelines and institutions which are designed to create people who have some authority to speak about technical matters—but we cannot predetermine whether the authority acquired through education will be infallible.
So on to the controversy!
PART ONE: THE OBJECT
As you can see, this is a circle divided by radial lines into 8 equal sectors. A “planisphere” is the reproduction of a spherical surface as a flat map.
The eight lines radiating from the center create eight sectors of 45 degrees each. Unfortunately, the piece is badly damaged and 40% of the planisphere is missing. Two large areas were lost, and they account for most of the damage. The breaking of the tablet dates to the sack of Nineveh, which was destroyed by a joint force of Babylonian and Medean armies in 612 BCE. But the same destruction that broke the tablet also accounts for its preservation; the clay disk was partly fired when the library that held it was burned.
It is now heavily restored, using plaster. The reverse has no inscription.
Questions: what is this object? What data does it record? Who made it, and for what purpose?
The planisphere has been studied in the past. Various Assyriologists have stepped forward over the course of many decades to put forward their personal theories. It is almost universally agreed to be a star map of some sort, recording the positions of important stars and constellations.
Archibald Sayce and Robert Bosanquet in the 1880’s posited that the planisphere had some calendrical purpose. The tablet was catalogued and briefly described by the assyriologist Carl Bezold in his Catalogue of the Cuneiform Tablets in the Kouyunjik Collection of the British Museum (5 Volumes, 1889-1899; See: Volume 3, 1893, Page 937).
The drawing above was published in 1912, when the obverse of K 8538 was drawn by the British Assyriologist Leonard King (See CT 33, (1912), Plate 10). In 1915, Ernst Weidner concluded that it had both astronomical and astrological significance and was probably a magical tablet used in exorcisms.
The most detailed study of the tablet was the 1989 study by Johannes Koch in his book Neue Untersuchungen zur Topographie des babylonischen Fixsternhimmels (Chapters 7-16). Koch concluded that the tablet represents the night sky over Nineveh in 650 BCE. Koch argued strongly that the planisphere was an instrument, intended to be rotated to predict or record the position of the stars on the horizon line above the city of Nineveh in a certain calendar year.
Imad Ahmad in 2003 simply describes the object as a clay astrolabe, handy to help the astronomer record information and keep time.
These are not the only voices in the discussion about what this object is and what it means, however.

Enter the Weird Zone
In 2008, Alan Bond, the managing director of a space propulsion company, Reaction Engines, and Mark Hempsell, a senior lecturer in astronautics at Bristol University, published a book on this object and their attempt to decode and explain its cuneiform inscriptions.
As we have stated, there is no universal and resounding consensus among experts about exactly what this planisphere is, who made it, what it says, and how it is intended to be read or used. We know roughly its provenance—it was brought back from Nineveh by Layard and is likely a part of Ashurbanipal’s collection of texts—but there is no one who has really nailed down the full import of this object and its meaning, save to agree that it is Neo-Assyrian and has SOMETHING to do with astronomy.
Bond and Hempsell have taken advantage of the fact that the tablet was associated with the Library of Ashurbanipal to argue that this circular clay tablet was actually not an original document generated by and for a Neo-Assyrian astronomer in the seventh century BCE. They argue instead that it was COPIED around 700 BCE by a Neo-Assyrian scribe, very likely from an earlier collection of clay documents.
This does have some limited plausibility, based on the planisphere’s association with Ashurbanipal. Nearly every document in the famous Library of Ashurbanipal was copied from a pre-existing source; Ashurbanipal was a notorious collector, and copies of local books and records were part of the tribute he demanded from vassals throughout his extended empire.
Nonetheless, Bond and Hempsell have gone far beyond this to weave a tissue of mythic associations which explain the origin, purpose and meaning of the object. They argue that the original cuneiform document was Sumerian (!), and was already over 2500 years old when it was copied for the edification of a Neo-Assyrian king.
Their rather drily titled A Sumerian Observation of the Köfels’ Impact Event further posits that the cuneiform planisphere could be decoded by use of a computer program, which could reconstruct the night sky in the ancient past.
To summarize the many articles which summarize the many arguments within their book is perhaps unfair. By the time scientific (or pseudo-scientific) arguments are this far removed from their source, it is difficult to say whether they really represent the real views of the original author.
Briefly, however, the authors argue that the planisphere is a “page from the notebook” of a Sumerian astronomer, who was recording events in the sky on June 29, 3123 BCE. The authors claim that the tablets record the trajectory of a large object traveling across the constellation of Pisces. They further argue that this object may have been a meteorite, and that the trajectory of the object recorded might be consistent with an old theory to explain a famous feature of the Austrian Alps—a huge rock-slide in Köfels.
To provide some necessary geological background here: Köfels is the largest rock-slide in the crystalline Alps. What you see above is a satellite image of the formation, which according to Wikipedia involved a 2.5 km horizontal displacement and 800 m vertical displacement of 3.2 km3 of rock and mud along the Ötz valley floor, making it the third largest known “sturzstrom” in the world, and easily the largest in Europe.
The Köfels formation is remarkable enough that it inspired a good deal of theorizing about its possible cause over the decades. Earlier in the 20th century it was posited that the site might have been caused by a meteoric impact, largely due to some of the rock formations in the area of the slide. Tremendous heat and pressure had caused some of the local stone to vitrify—turn to glass—when the slide occurred. This type of rock is actually called “köfelsite” in Europe, which shows you how unique and interesting it was to geologists working with the evidence at the time.
Bond and Hempsell seem to be returning to this “meteor” theory in 2008, despite the fact that more recent geological papers on the slide have posited other theories which are more widely accepted to explain that vitrification. The glassy rock formations in the area were explained in the 1970’s simply by appealing to the sheer mass of rock that moved when the mountainside collapsed.
Similar formations can be seen around the world in any place where a mega-landslide occurs. The rock that liquifies when mountains fall has been dubbed “frictionite” by the scientists who study it more broadly, and it can be found in the Himalayas, Nepal, and Peru as well as in Austria, always in connection to a massive slide of earth and stone.
Sadly, this is not the only obstacle that the Bond/Hempsell hypotheses have to confront. Correlating their interpretation of this cuneiform tablet with the Köfels Landslide is also contradicted by carbon dating of the trees which were buried when the slope crashed into the valley below.
A buried forest is some of the best carbon-dating material that a scientist could ask for, and very unlikely to be “contaminated” by earlier material, as Bond and Hempsell have argued. Scientists who studied the wood very confidently dated the Köfels Landslide to around 8700 years ago based on that evidence…and two different teams who ran carbon dating studies 30 years apart dated the slide to the same period.
Upshot? Both geology and absolute dating make it very unlikely that the clay tablet and the Köfels slide are related. So even if Bond/Hempsell are correct, and their tablet really does record an astronomical event witnessed in 3123 BCE…there is no way that this record can explain a rock slide that dates from 6700 BCE.
By extension, all the rest of the gymnastics that Bond and Hempsell used to try to link the fireball of 3123 BCE to the Köfels slide are best dismissed as incorrect. And possibly even a little silly.
There is no crater at Köfels because Köfels was not caused by a meteoric impact. We do not need to entertain the far-fetched Bond/Hempsell scenario in which a meteorite bounced around the Alps and exploded in the air, causing the landslide without leaving any other significant geological evidence of its existence. All the hand-waving about the angle of the trajectory, the clipping of the Gamskogel mountain, and the aerial explosion are not necessary.
Does this mean that the Bond and Hempsell’s book is completely without scientific merit, and that their translation of the ancient tablet is absolutely by necessity wrong?
Well…no. Reluctantly we must admit that disproving one aspect of a hypothesis or theory does not disprove all its unrelated parts.
To do that, we actually have to appeal to archaeology and philology, in particular the field of cuneiform studies. We can certainly do that. We can also turn to the work of scholars who specialize in ancient astronomy, to see whether the planisphere can be linked to what is known from many other sources about the practice of astronomy in the Iron Age.
We can also argue that the standards and behavior or true scholars are absent from the work of Bond and Hempsell.
What we cannot do, unfortunately, is fill in the blank spaces of a shattered artifact with absolute certainties.
We also cannot prevent human beings from searching for evidence not of the abstract truth, but for proof of what they already believe is true. Bond and Hempsell have apparently stated that their decoding of this cuneiform planisphere and its ancient report of a mysterious Fire in the Sky was quite easy to achieve…since they already knew what they expected it to say.
Sometimes, all the answers do not come in a neatly wrapped package, nor do they come all at once.
Sometimes knowledge can skip like a stone through time. It is hypothetically possible that a Sumerian priest could make an observation, that a Neo-Assyrian scribe could make a copy, and that a British maverick could make a ground-breaking and innovative translation, to prove a bold hypothesis. It isn’t what happened in this case…but it isn’t impossible.
All along the way, the thread of truth is fragile and easily broken. All along the way we confront the demons of human fallibility. And in the effort to fill in the blank spaces and the unknowns, we must use our imaginations.
Is it any wonder that we cannot explain every fire in the sky?