Today is the summer solstice, on which I like to do posts about archaeoastronomy. Today I’d like to discuss a well-known site, Sun Temple at Mesa Verde, which as its name suggests has long been associated with astronomical observations. As we’ll see, however, it appears that some of the early interpretations of the site’s architecture haven’t held up under further examination. This is another good example (along with Wupatki) of the need to carefully analyze proposed archaeoastronomical alignments.
Like many sites at Mesa Verde, Sun Temple was excavated and partly reconstructed in the early twentieth century by the pioneering archaeologist Jesse Walter Fewkes. Fewkes named the site “Sun Temple” after finding a feature that he interpreted as a “sun shrine” aligned to the position of sunset on the fall equinox. After identifying this possible alignment, Fewkes looked at the orientation of the building to see if there were any other astronomical alignments present. Sun Temple is D-shaped, with the flat side of the “D” to the south (a shape and orientation that those familiar with Chaco may find familiar), so the straight front wall was an obvious place to check for alignments. Fewkes, presumably guided by the equinoctial alignment of the shrine, initially checked to see if the front wall aligned to the positions of sunrise/sunset on the equinoxes, which would be the same and would mean the wall was oriented due east-west. He found that it was not, but was rather aligned about 20 degrees north of due east at the east end, and 20 degrees south at the west end.
In his published reports Fewkes went on to conclude from this alignment that the front wall was actually oriented to the summer solstice sunrise. This is an important event in modern Pueblo societies, and subsequent research has found evidence for alignments to it in prehistoric Pueblo sites as well, so on first glance this seems like a reasonable conclusion. When archaeoastronomer Jonathan Reyman began to research the site using modern techniques in the 1970s, however, he found that it didn’t hold up, and published a short article explaining why.
The basic gist of Reyman’s article is very simple: The front wall of Sun Temple is indeed oriented to about 20 degrees north of east, but this is not the same alignment as the summer solstice sunrise at this latitude, which is more like 30 degrees north of east. Fewkes appears to have simply made a simple mistake. It’s not clear exactly how this would have happened, but Reyman suggests he either made a mistake in his notes or his notes were unclear and he became confused when writing them up for publication. In any case, this is a pretty clear-cut case of a mistake in the literature being corrected, and Fewkes’s error does not seem to have been propagated since. (Note that the NPS link I gave above says nothing about a solstice alignment.)
Reyman did also confirm that the “sun shrine” is aligned to the equinoctial sunsets and may well have been used to observe them, so the name “Sun Temple” remains appropriate (or as appropriate as it ever was). This is an intriguing building for a lot of reasons, some of which do support the idea that it had an astronomical function, but that’s a discussion for later. Sun Temple is also one of the most accessible sites at Mesa Verde, being on a mesa top where it can be visited without a guided tour, and it is well worth visiting even though it’s quite different from the cliff dwellings for which the park is best known.
Reyman JE (1977). Solstice Misalignment at Sun Temple: Correcting Fewkes The Kiva, 42, 281-284