On a recent photo trip to finish a portfolio for Arizona Highways, I found myself poking around a rock art site along the lower Gila River west of Gila Bend. The lighting was poor and the sun was glaring, but that wasn't enough to keep me from spotting a great rendition of a total solar eclipse. The petroglyph is compared below to a photo I took of the July 1991 total eclipse at Cabo San Lucas, Mexico. Look also at the exposure of totality in the sequence at the top of the page. Both images bear a striking resemblance to the version etched in stone.

The petroglyph consist of two concentric circles representing the sun and moon surrounded by a wavy line making an appropriately-stylized solar corona. It is also thought that concentric circles depict portals through which shamans in trance, spirits and gods travel to and from other levels of reality. Portals can contain several circles, the number probably relating to the different levels involved or possibly other characteristics. (On my Sacred Sunrise page, I related two concentric circles to a creation theme.) There is a concept called "hole in the sky" that figures into Native American stories of creation and emergence. A total solar eclipse reminds me exactly of that—a black, otherworldly hole in the sky. All these thoughts might very well be related.

When dealing with rock art that seems to depict an astronomical event, one of the first questions to ask is whether or not that event can be recognized and dated. The eclipse petroglyph contains a curious dot just above the corona. If that were found to coincide with a planet or bright star during a known eclipse, it could go a long way towards assigning a date to the glyph. Consulting the Five Millennium Catalog of Solar Eclipses by Fred Espenak and Jean Meeus, I searched back to 2000 BCE for total solar eclipses that would have been visible from the rock art site. I didn't find any that included a bright object anywhere close to fitting the position of the dot. I expanded the search to include eclipses in which the path of totality barely missed the site, but came up with the same result. It was clear I would not be able to use the placement of the dot to reckon a date.

I looked at the eclipse dates again and was struck by one that occurred on March 7, 1076 CE. That would have been just 22 years after another noteworthy astronomical event—the 1054 supernova in the constellation Taurus. The petroglyphs at left, from the Painted Rock Site, are thought to depict that event as it would have looked on the evening of April 13, 1054 in the western sky.

There is other rock art believed to depict the supernova at sites along the lower Gila River. That implies people in the area were paying attention to the sky during this time period and creating rock art that in some way dealt with the events. If they saw the total eclipse of 1076, it is reasonable to assume they would make some sort of depiction in stone.

So, did the Hohokam along the lower Gila River see this eclipse? It is very highly likely. Totality would have occurred during the late afternoon with the sun well placed above the SSW horizon. The lower desert enjoys generally clear skies and it would have been difficult to overlook the darkening effects of a total eclipse. Also, the site where I found the glyph was situated right along the eclipse centerline. That allows more room for computation inaccuracies that increasingly crop up the farther back in time you go.

Useful Links At NASA Eclipse Website

World Atlas of Solar Eclipse Paths

Solar Eclipse Search Engine

Catalog of Solar Eclipses

The Five Millennium Catalog of Solar Eclipses provides an estimate of the possible inaccuracies. In the map below, I depicted the ±11 minutes in longitude given by the catalog for eclipses of this date range. It shows the amount the eclipse path could have been shifted in the actual historic event. You can see that a site on the red centerline would have remained well within the blue lines that show the northern and southern limits of totality. In comparison, if this eclipse occurred around 500 BCE, the amount of possible shift would have increased tenfold, placing the centerline anywhere within a 200 mile-wide area. Does any of this evidence prove that the eclipse petroglyph is a depiction of the 1076 event? Not really, but it points to it being a strong possibility. The area almost certainly saw a total eclipse and it fits a time frame when the Hohokam were known to be making similar astronomical petroglyphs. Plus, seeing the centerline follow that stretch of the waterway so closely, I just can't get over how this Eclipse Along The Gila seems made especially for these prehistoric desert sky-watchers. Of course they would capture it in stone. There are times when you just have to trust the signs and take the leap.
