Credit: NASA/Aubrey Gemignani
Astronomy can often give us clues to the past that are otherwise lost to history. In one case, an Italian astronomer has proposed that a dramatic total solar eclipse triggered a religious crisis in ancient Egypt and led the last pharaoh of the 4th dynasty to abandon the pyramid-building of his ancestors.
Related: The greatest eclipse for the rest of our lives — join Astronomy in Egypt for a total solar eclipse
A strange tomb
Rising out of the desert in South Saqqara is a curious structure: a flat, table-like building that resembles a half-completed pyramid. Known today as the Mastabat al-Fir’aun, its interior has all the usual rooms and structures of the more famous Giza pyramids, and obviously derives design inspiration from those earlier structures. This was the resting place of Shepseskaf, the last ruler of Egypt’s fourth dynasty, who probably reigned for only four years before dying around 2498 B.C.E. His reign marked a dramatic turning point in Egyptian history.
Why did Shepseskaf build such a small tomb for himself in such an out-of-the-way corner of the desert? For decades Egyptologists have proposed many solutions. Perhaps he was trying to cement his authority by planning his burial place closer to his ancestral homeland. Perhaps there was a dispute with the high priests of his court. Maybe he simply ran out of money.
A solar solution?
But recently Giulio Magli, an Italian astronomer, has proposed an explanation of much more cosmic proportions in a paper posted to the arXiv preprint server. A total solar eclipse passed over central Egypt during the estimated reign of Shepseskaf, and pyramid-building is associated with worship of the Sun. Perhaps Shepseskaf and his people believed that the Sun had betrayed them, and that different deities and cosmic beings deserved recognition in the burial of a pharaoh.
The morning of April 1, 2471 B.C.E. started out perfectly normally, with the Sun rising in the east in the early morning. But within minutes the eclipse began, and by 7:59 A.M. it was total, with the band of darkness reaching well into the fertile Egyptian heartland, including the holy city of Buto. Memphis, the capital of Egypt of the time, stood a little further south, but experienced a 95 percent totality — more than enough for court astronomers to take notice, especially as word of the event spread from the north.
At the time, total solar eclipses were impossible to predict. Astronomers wouldn’t have that ability until the early 18th century with the work of Edmond Halley. Prior to that time, astronomers constructed elaborate cyclical calendars known as Saros cycles that could roughly predict an upcoming eclipse. But even that approximation was unavailable to Shepseskaf. This eclipse would have come as a total, and unwelcome, surprise.
Magli notes that surely the Egyptians would have noted many eclipses over the course of their millennia-spanning history, but they tended to avoid recording these events. This is quite unlike other sophisticated ancient cultures, like the ancient Babylonians and Chinese, who duly noted these strange occurrences. One hypothesis is that the ancient Egyptians worshiped the Sun as a primary deity and viewed eclipses as dark and dangerous omens, not wishing to preserve it in their written records.
The cult of the Sun is directly linked to the practice of pyramid building that exploded with the 4th Dynasty pharaohs. But during Shepseskaf’s brief reign, the Sun, and by extension the Sun god, did not behave as expected, and so he chose to turn away from that tradition.
Uncertainty remains
This is of course highly speculative. The dates of Shepseskaf’s reign are uncertain, as Egyptologists have to rely on counting backwards from (unreliable) listings of pharaohs and their reigns. And the eclipse too, while more grounded in mathematics and astronomy, is also uncertain. We know for sure that an eclipse happened around that time, but the precise moment and location depends on the rotation of Earth, which slowly but measurably changes over thousands of years. This effect can only be modeled to give us an approximate date for the eclipse. And because we have no written records of the eclipse to match the calculations to, we have to leave the estimate as it is.
Still, the close connection between these two events — a total solar eclipse and Shepseskaf’s decision to not build a pyramid — is intriguing. We’ll likely never know his true motivations for building his Mastabat, or what he, his priests, or his people thought about the eclipse that darkened their April morning.
But we do know that eclipses ignite fear, curiosity, and wonder even in modern times when we know to the second when they will occur and what is happening. An event of this magnitude almost five thousand years ago may have been more than enough to make a pharaoh doubt his cosmic patrons, and break traditions that were already ancient even to him.
