A clay tablet inscribed around 700 BC had hidden its secrets from researchers for over 150 years, but now its cuneiform script is translated and known to describe an asteroid impact at Köfels, Austria that occurred way back in 3123 BC.

The tablet was found by Henry Layard in the remains of the library in the Assyrian Royal Palace at Nineveh, and was made by an Assyrian scribe who copied a Sumerian astronomer’s recorded notes. The tablet depicts astronomical drawings, known constellations and an object that was unknown. Taken in altogether, an intriguing and puzzling picture.

To decipher the cuneiform script on the clay tablet, modern software programs were used. The programs were sophisticated enough to go back in time to reconstruct the positioning of stars from ages gone by.

From there, it was a matter of uncovering the correct historical date that matched the information on the tablet. Then also, isolating the trajectory of that unknown depicted object.

According to Bristol University:

Half the tablet records planet positions and cloud cover, the same as any other night, but the other half of the tablet records an object large enough for its shape to be noted even though it is still in space. The astronomers made an accurate note of its trajectory relative to the stars, which to an error better than one degree is consistent with an impact at Köfels.

The observation suggests the asteroid is over a kilometer in diameter and the original orbit about the Sun was an Aten type, a class of asteroid that orbit close to the earth, that is resonant with the Earth’s orbit.  This trajectory explains why there is no crater at Köfels.  The in coming angle was very low (six degrees) and means the asteroid clipped a mountain called Gamskogel above the town of Längenfeld, 11 kilometer from Köfels, and this caused the asteroid to explode before it reached its final impact point. 

As it traveled down the valley it became a fireball, around five kilometres in diameter (the size of the landslide).  When it hit Köfels it created enormous pressures that pulverized the rock and caused the landslide but because it was no longer a solid object it did not create a classic impact crater.

The landslide centered at Köfels had been a mystery of its own—how did it happen? In the end, modern know-how solved not just one mystery, but two. That’s science at its best …

The cuneiform tablet translated in its entirety along with the research analysis and conclusions of Köfels impact are found in the book, A Sumerian Observation of the Kofels’ Impact Event.

It is published by Alcin Academics, ISBN 1904623646.

Researchers and References

• Research by: Alan Bond, Managing Director of Reaction Engines Ltd and Mark Hempsell, Senior Lecturer in Astronautics at Bristol University
• The tablet is object number K8538, known as “the Planisphere”, in the British Museum. 
• Read the Bristol University press release,
  Cuneiform clay tablet translated for the first time or the embedded version below
• Image from Bristol University