Today is the summer solstice, on which I typically make posts about archaeoastronomy, so I’m going to take a break from my very gradual series of posts on tracing the connections between ancient and modern Pueblos to speculate a bit about the role of astronomy at Chaco. Briefly, what I’m proposing is that the rise of Chaco as a regional center could have been due to it being the first place in the Southwest to develop detailed, precise knowledge of the movements of heavenly bodies (especially the sun and moon), which allowed Chacoan religious leaders to develop an elaborate ceremonial calendar with rituals that proved attractive enough to other groups in the region to give the canyon immense religious prestige. This would have drawn many people from the surrounding area to Chaco, either on short-term pilgrimages or permanently, which in turn would have given Chacoan political elites (who may or may not have been the same people as the religious leaders) the economic base to project political and/or military power throughout a large area, and cultural influence even further.
I don’t have any specific research papers to discuss on this topic because as far as I know no one has really looked at it quite this way. It’s similar in some respects to the theories of the Solstice Project, although I don’t buy that astronomical alignments were quite as important in the Chacoan system as they propose. There is also some overlap with the theories of various archaeologists, but none of them have put the pieces together in quite this way. This may be because it’s demonstrably wrong, but if it is I haven’t seen the evidence that disproves it yet (but would be very interesting in doing so).
This theory first occurred to me when I was reading about Tiwanaku in Bolivia, which was a prehistoric society that, like Chaco, left very impressive physical remains in a very isolated location with few obvious economic advantages. As I noted in my post on Tiwanaku, the similarities actually go well beyond that, extending also to the shifting interpretations by archaeologists and the evidence for astronomical alignments. Most relevant in this context is the theory of John Janusek at Vanderbilt, whose theory of Tiwanaku is the model for the theory I’m suggesting here for Chaco. As he wrote in one paper, which I also quoted in the earlier post:
Tiwanaku’s long rise to power in the Andean altiplano was predicated on the integration of diverse local ritual cults and various symbolic dimensions of the natural environment into a reasonably coherent, supremely elegant and powerfully predictive religion. The shifting physicality of Tiwanaku’s religious monuments attests the construction and ongoing transformation of an urban landscape that not only visually expressed the altiplano’s ‘natural’ forces and cycles, but, via recurring construction and ritual, simultaneously shaped new social practices and Tiwanaku’s ever-increasing political influence and productive coordination, intensification and expansion. Tiwanaku was an imperfect and potentially volatile integration of religious cults, productive enterprises and societies. The material objectification of a seductive religious ideology that infused the monumental centre with numinous natural forces and simultaneously projected those forces across distant Andean realms helped drive Tiwanaku’s very worldly imperial mission.
Tiwanaku was apparently the first society in the altiplano to develop the level of astronomical skill which allowed it to develop such a “powerfully predictive” religion, and my application of a similar theory to Chaco relies on it also being the first place that developed a comparable knowledge of astronomy in the Southwest. I hadn’t really thought about this before reading Janusek’s work, but as far as I can tell it does in fact seem to be the case. Ray Williamson’s somewhat dated but still very useful book on Native North American astronomy (which I reviewed here) doesn’t mention any evidence of Southwestern astronomical knowledge predating Chaco, and I haven’t seen any other publications that do either. Granted, some of the evidence for astronomical evidence comes from rock art which is difficult or impossible to date, but at least when it comes to building alignments, which are more securely datable, the Chacoan great houses seem to be the earliest manifestation of detailed astronomical knowledge. Some earlier sites do show general alignments to cardinal directions and so forth, but the precise alignments to solstices and lunar standstills that are characteristic of Chacoan buildings do really seem to be innovative. I’m not totally certain that there aren’t counterexamples out there, though, so if anyone knows of any I’m very interested in hearing about them.
If this is in fact the case, it opens up several additional lines of inquiry. First, if Chaco was in fact the first place in the (northern?) Southwest to attain detailed astronomical knowledge, where did that knowledge come from? Many discussions of Chacoan astronomy have assumed, implicitly or explicitly, that the answer is “Mexico,” but I’m not so sure. There is definitely extensive evidence of contact with Mesoamerica at Chaco, but it’s all fairly indirect and there are lots of important aspects of Mesoamerican culture that are noticeably lacking. Mesoamerican astronomical knowledge was certainly impressive, and certainly predates the rise of Chaco, but given the general context I think it’s still an open question whether the Chacoans got their knowledge from contacts to the south (either directly or via the Hohokam and/or Mogollon) or developed it independently. This is an area that would definitely benefit from further study.
Secondly, why Chaco rather than somewhere else in the region? This is sort of the key question hanging over everything about Chaco, and so far no one has come up with a broadly convincing answer. I don’t have one either; the astronomy theory I’m proposing here answers the “how” of Chaco but not the “why.” It could be that, as some archaeologists have proposed, the physical setting of the canyon had unique attributes within the region that contributed to its ritual importance from an early period, which from my perspective would have provided the impetus for the development and/or integration of new astronomical knowledge into existing belief systems. Alternatively, as other archaeologists have argued, there could have been economic advantages to the location, which are not obvious to modern eyes but were sufficient to give Chaco an important role in the region, which may have made it a promising place for new ideas to develop or be introduced. And finally, maybe it’s all just a matter of historical contingency: this was where people happened to figure this stuff out, and that’s what made it attractive to others for both religious and economic reasons.
Another question is when this would have happened. Chaco was occupied for hundreds of years, but its florescence as a regional center was relatively brief, lasting roughly a century from AD 1030 to 1130 or so. One natural conclusion would be that the development of new astronomical knowledge happened at the start of this period, but I suspect it actually began earlier, probably during the period (roughly the late ninth and tenth centuries, or the late Pueblo I period) when Chaco was just one of several “proto-great-house” communities in the San Juan Basin that were more or less equal in size and influence. Over time, the advantages of the Chacoan rituals over the others would have become apparent, perhaps through fortuitous stretches of good weather and/or military successes by Chacoan warriors. This would have set the stage for Chacoan influence to expand on a vast scale during the eleventh century.
As the reference to military success in the previous paragraph suggests, I don’t see the expansion of Chacoan religious influence fueled by astronomical knowledge as having necessarily been entirely peaceful. Here again, the parallel to Tiwanaku is instructive. Note Janusek’s reference to Tiwanaku’s “very worldly imperial mission” in the quote above. I suspect what we would today see as “religious” and “secular” impulses were much more intertwined at Chaco, as indeed they have been shown to be in many societies.
All that said, I’m not totally convinced by this theory myself, and there are many strands of the Chacoan record that it doesn’t really seem to account for in an obvious way. I figured this was a good opportunity to toss it out there, though, to see whether it’s worth pursuing further.
Janusek, J. (2006). The changing ‘nature’ of Tiwanaku religion and the rise of an Andean state World Archaeology, 38 (3), 469-492 DOI: 10.1080/00438240600813541