In 1973 an international team of anthropologists called the Combined Prehistoric Expedition (CPE) headed by Fred Wendorf and Romuald Schild were 100 km west of Abu Simbel, on a break in the blazing heat, when someone noticed potsherds and fine stone tools. They had discovered what came to be known as Nabta Playa. The CPE began excavating there every winter and uncovered, cataloged, and radio carbon dated numerous layers of artifacts dating from circa 7,000 BCE to 3,300 BCE. They found tombs of cattle that had been ritually interred and remnants of jewelry that must have come through trade from as far away as the Mediterranean and the Red Sea. Wendorf and Schild began calling the site a Neolithic-era “regional ceremonial center” even before they noticed what Nabta Playa would become famous for—the megaliths.
It seems strange they didn’t notice the megaliths, even to Fred Wendorf himself who wrote, “The megaliths of Nabta were not recognized or identified for a long time. We began to realize their significance only in 1992. . . .” (ref. 1) and “it is not clear why we failed to recognize them previously…. It was not that we did not see them, because we did, but they were either regarded as bedrock or, in some instances where it was clear they were not bedrock, regarded as insignificant.”
The megaliths and megalithic constructions at Nabta Playa clearly constitute the central aspect of the site and the rituals that were conducted there, and they required much effort and social organization to construct. There remain mysteries about the megaliths, but one function essentially everyone agrees upon—they served an astronomical purpose of some sort. So, clearly, we can say that Nabta Playa was not only a regional ceremonial center, it was a Neolithic era regional astroceremonial center.
The megalith arrangements consist largely of six alignments of stones that radiate outward from one central point, like spokes of a wheel. There are three alignments to the north-northeast direction and three alignments to the east-southeast. The most robust interpretation is that the north-northeast alignments refer to one or more circumpolar stars, and the east-southeast alignments refer to the brightest star in the sky Sirius and the stars of Orion’s Belt. Given that Nabta Playa was used, constructed, and reconstructed over more than 26 centuries, it is likely the megalith alignments represented celestial events at more than one epoch. Because stars “move” due to precession of the earth, any single alignment can refer to any given star at only one specific date. Thus the multiple megalith alignments may have referred to certain sets of stars at certain ancient dates.
In 1998 astronomer Kim Malville and the CPE mentioned the megaliths in a report published in Nature magazine (ref. 3). However, that paper focused mainly on the “Calendar Circle”—a separate device made of small stones, not megalithic, that we will consider later in this essay.
The first mention of astronomy of the megaliths was in a brief article by Wendorf and Malville within the massive book published by the CPE in 2001. However, I teamed up with my old colleague Paul Rosen (a leader in space based radar remote sensing) and used new satellite imagery and our own on-site measures to correct errors in that early report, in a peer reviewed journal article in 2005. In 2007 Malville and the CPE used our corrected data to propose a new set of megalithic alignments at Nabta Playa including the rising of Sirius circa 4500 BCE and 3500 BCE. Then Robert Bauval and I showed in our book Black Genesis: The Prehistoric Origins of Ancient Egypt, March 2011, that those two Sirius alignments (4500 BCE and 3500 BCE) are very much strengthened by simultaneous, and very precise, megalith alignments to the bright star Dubhe to the north in the Egyptian Bull’s Thigh constellation. And we conclude that is the same set of alignments that informed the early Old Kingdom Egyptian temple arrangements and became the important stretching of the cord ritual.
These two sets of alignments thus accounted for four of the six major lines of megaliths at Nabta Playa. We suggest this ritual of the simultaneous sighting of the rising of Sirius together with a bright circumpolar star originated at Nabta Playa and was later taken to the Nile Valley. At Nabta Playa the star sightings were both ritual and actual, involving the megalithic constructions and the giant natural reflecting pool that was the ancient seasonal lake. Later, in the pharaonic culture the ritual became more stylized and symbolic, as we describe in Black Genesis: “The ancient Egyptian texts and temple reliefs explain that stretching the cord was carried out by a priestess, who represented a deity associated with the stars, and the pharaoh. Both the priestess and pharaoh held a rod and a mallet, and a rope or cord was looped between the rods. The priestess stood with her back to the northern sky and faced the pharaoh. … A further clue to the ritual is that the pharaoh observed carefully the motion of a star in real time. Inscriptions on the Temple of Horus at Edfu, accompanying portrayals of the ritual, quote the pharaoh: ‘I take the measuring cord in the company of Seshat. I consider the progressive movement of the stars. My eye is fixed on the Bull’s Thigh constellation. I count off time, scrutinizing the clock….’ This is also what might have happened at the ceremonial center of Nabta Playa thousands of years earlier….”
Around 3300 BCE, the Nabta Playa area became the uninhabitable, extremely dry “hyper arid” desert that it is today. Directly following that date is when the earliest temples of the ancient Egyptian civilization began popping up in the Nile valley, especially the temple of the goddess Satis on Elephantine Island near Aswan. The temple was rebuilt several times over 3,000 years—its axis changing to align with the rising of Sirius as the star’s position changed through precession—the first known version of the temple was built circa 3200 BCE.
Throughout Ancient Egyptian civilization the New Year was marked by the annual reappearance at dawn of Sirius, an astronomical event that also heralded the life-giving and civilization-supporting inundation of the Nile River. By the time of New Kingdom Egypt, at least according to the great tourist Herodotus, the Egyptians had forgotten that the source of the flooding of the Nile was the monsoon rains that engorged the river upstream. But they did remember that the floods would be symbolically heralded by the heliacal rising of Sirius. Earlier, in the time of Nabta Playa when the megalith builders tracked the rising of Sirius, the monsoon rains fell directly on the playa and inundated the seasonal lake that would in turn reflect the starlight along the megaliths they had constructed. There, the connection of the heliacal rising of Sirius with the coming of the annual, life-supporting rains was direct, obvious, visceral—the heavenly events coinciding with the new year renewal of the playa on Earth. When the monsoon rains moved south and left Nabta Playa uninhabitably dry, the people moved to the Nile Valley and created the greatest temple-building civilization of history.
Clearly, we believe the megalithic tracking of Sirius and the circumpolar thigh constellation is a very robust interpretation for the function of some of the megaliths at Nabta Playa. It is the astronomy associated with earlier dates that is more controversial and connects with the most mysterious aspects of the site. First, I need to mention the most famous feature of Nabta Playa—the “Calendar Circle.” The Calendar Circle is not megalithic; it is made of stones that come up to about one’s knee, or smaller. As we describe in Black Genesis the studies, publication, and treatment of the Calendar Circle suffered a convoluted history. For some reason, the first publication of it was not until the 1998 Nature paper. However, the primary mapping and archaeological analysis of the circle was done in 1991 and 1992, and it was surely known about in 1974. As to the astronomy of the Calendar Circle, the non-controversial part is this. Eight stones on the circumference of the circle form four “gates” that create two “sight line windows”—one window indicates the north-south direction; the other window indicates the rising sun on summer solstice. Also, the location of the site itself at about 22.5° north latitude, near the tropic line, means the sun passed exactly overhead twice per year during the weeks around summer solstice, and standing stones would cast no shadow at noon.
The controversial part of the interpretation of the Calendar Circle refers to the contents of the circle—six standing stones arranged in two sets of three. This interpretation was published in The Origin Map and presented at professional conferences in Rhodes, Greece, at conferences around the world, in a TV/DVD graphic animation, and, again, together with Robert Bauval in our recent book Black Genesis. My approach to solving the puzzle of the Calendar Circle contents is to consider the solstice and meridian gates of the circle as clues to its overall function. The solstice gate tells a user the relevant time of year—around the summer solstice. The meridian gate tells the user where to look in the sky—up along the north-south meridian (which is the same sky reference astronomers still use today). Together, the gates also tell the user of the circle what time of day to look—just before sunrise while the sky is still dark. Then the contents of the circle form a simple “star map” that the user can visually “slide up into the sky” to identify the asterism indicated inside the circle. The radiocarbon dates from a nearby hearth supply a clue as to what epoch—around 4800 BCE. Calculating the appearance of the starry sky then, it was apparent that the three stars of Orion’s Belt would be a good candidate asterism for the lower set of three standing stones in the circle. And the fit occurred in multiple ways—just the right altitude was represented, and the best fit date (also coincident with the radiocarbon date) occurred at a special time in the long—term precession of those stars—exactly half way between southern culmination and northern culmination. A more speculative interpretation for the other set of three stones inside the circle occurred—they match the top part of the Orion constellation (the shoulders and head stars) at the opposite part of the precession cycle about 12,000 years earlier. So the Calendar Circle was likely constructed and used around 5000 BCE (certainly not 17,000 BCE), and it was a diagram to teach about the long-term motion of the starry sky. Just as the summer solstice sunrise alignment of the circle teaches about the annual motion of the sun through the sky, the inner stones of the circle teach about the 26,000-year precession motion of the constellations. It is thus unified with the megalithic alignments at Nabta Playa which also refer to Orion’s Belt as well as to the rising of Orion’s companion in the sky, Sirius.
Mystery of the Bedrock Sculptures
The most mysterious parts of Nabta Playa lie below the star-aligned megaliths, underneath the playa sediments. According to paleoclimatologists, and the radiocarbon dates of sediment layers, the last period of heavy sedimentation that laid down the final thick layer of sediments ended around 5000 BCE. Therefore megaliths embedded in that layer must have been placed then, or more recently. But the puzzle is complicated by what is found underneath the playa sediments, especially underneath the centerpiece called “Complex Structure A” CSA. All the megalith alignments radiate out from CSA. CSA was composed of several parts: on top of the sediments were megaliths arranged in a large oval with a standing stone in the center; under that was some playa sediment and then a large sculpted megalith (called the “cowstone”); and then underneath the cowstone sculpture was a sculpted lump of living bedrock about four meters under the surface of the playa sediments. And CSA sits in a field of about 30 similar complex structures—all similar except the others don’t have a cow-stone sculpture.
Nabta Playa is a bedrock basin covered by a few meters of sediments that were laid down mostly since the end of the last ice age, and especially in a series of “humid interphases” from circa 9,500 to 7,000 years ago. When the CPE excavated the Complex Structures and found them to cover bedrock sculptures under three or four meters of sediments, they were at a loss as to how to explain their creation. The standard idea of Neolithic culture is such structures could not have been built by them. So the CPE theorized that the people of Nabta Playa, more recent than 7,000 years ago, somehow located the bedrock lumps (called “lenses” of quartzitic sandstone); then they dug through the sediments; then sculpted the bedrock lumps and then they filled the sediments back in; then they arranged the oval of megaliths on top of the sediments, leaving them thus for us to dig up today. Obviously there are several problems with that scenario. For one, CSA is the centerpiece of all the megalith alignments, so it must predate them, the earliest of which is at least 6,500 years old. Another problem with the scenario is that there was no possible way the Neolithic people could have figured out where the bedrock lumps were, under several meters of sediments, in order to carry out such a strange series of construction steps, not to mention why they would do such a thing in the first place.
We suggested that a more likely solution is the bedrock sculptures actually are older. By the time of their 2007 article, the CPE agreed that it is likely the bedrock sculptures preexisted as part of an older “symbolic landscape” that was marked by cairns or a sequence of constructions leading up to the Complex Structures we find today. The megalithic alignments placed on top of the sediments from 5000 BCE to 3500 BCE therefore incorporated, in fact arranged as their centerpiece, the much older bedrock sculptures. When were they first constructed; for what purpose? Why were they so important or sacred that people continued to maintain them and incorporate them in their ceremonial constructions for thousands of years? Does such continuity of construction through time imply a greater degree of cultural (or religious or technological) continuity than previously believed? The answers to these questions are unknown. It is interesting that these bedrock sculptures date back to the same earlier epoch as it has been proposed does the Great Sphinx at Giza which itself is a giant bedrock sculpture. Geologist Robert Schoch, and others, have shown that the Sphinx and its bedrock enclosure are weathered by heavy rains that occurred before the standard dating of Dynastic Egypt. It is essentially the same rainy climate pattern that laid down the sediments on top of the bedrock sculptures at Nabta Playa—which leads us to intriguing possible connections of the more ancient bedrock sculptures to a possible earlier astro-ceremonial culture connected with the earliest constructions at Giza, but due to space constraints on this essay I will have to refer the reader to our book Black Genesis for that.
Thomas Brophy along with Robert Bauval are the co-authors of Black Genesis, The Prehistoric Origins of Ancient Egypt (Inner Traditions, March 2011).