Rock Carving May Illustrate Eclipse's Allure 1,000 Years Ago

Aug 14, 2017

As excitement over the Aug. 21 solar eclipse mounts, researchers at the University of Colorado Boulder think back to the how another eclipse may have been memorialized -- 1,000 years ago.

In New Mexico’s Chaco Canyon, a petroglyph -- or rock carving -- by the early Pueblo people is believed to be their depiction of a total solar eclipse from the year 1097, said CU Boulder professor emeritus J. McKim “Kim” Malville. A solar physicist, Malville also researches archeoastronomy, which looks at how people in the past regarded events in the sky.

The carving, which was discovered in 1992 during a Chaco Canyon field school led by Malville and then-Fort Lewis College professor James Judge, features a circle with curvy lines protruding from it.

“To an astronomer -- maybe not to too many other people, but to an astronomer -- (it) looks like a image of the solar corona that was disturbed by a so-called coronal mass ejection,” Malville said.

A coronal mass ejection is when a giant eruption of plasma is released during a solar event, such as an eclipse.

Many cultures viewed the sun as a mysterious deity that had great power over them, Malville said. He added that during an eclipse, it would have been a rare moment for the people to “almost see the face of that god.”

Piedra del Sol (Rock of the Sun) is in Chaco Canyon, N.M.
Credit Courtesy of University of Colorado-Boulder

The rock featuring the petroglyph is known as Piedra del Sol (“Rock of the Sun”) because it also has a spiral petroglyph on the east side marking sunrise just before the June solstice. Fifteen days prior to the summer solstice, a triangular shadow is cast by a rock on the horizon crossing the center of the spiral. The shadow is believed to be part of a “countdown” to the summer solstice.

Witnessing the eclipse may have had a lasting impact on the people there, Malville said.

“All of the great houses which they built after that eclipse always were placed at a location where they could see the sun rise at June or December (solstice) behind a prominent feature on the horizon,” he said. “Until that time, none of the great houses they built in Chaco Canyon had that characteristic.”

Malville said there also is a pictograph (or paintings) in Chaco Canyon that is believed to depict Halley’s Comet in 1066.

The paintings on the canyon walls show a series of concentric circles with what appears to be flames streaming from them, he said. The pictograph’s high location means a scaffold or ladder of some kind would have been required to draw it.

“That scaffolding would have given them an airily view of the eastern horizon where they comet appeared,” Malville said, adding that nearby is another controversial pictograph that some believe represents a supernova from 1054.

Petroglyphs found in Chaco Canyon, N.M.
Credit Courtesy of University of Colorado-Boulder

While there are those who equate an eclipse with something potentially ominous, Malville said he believes the people of Chaco Canyon saw it differently.

“To have this possible supernova -- 1054 -- and the comet of 1066 and the eclipse of 1097, if these are true interpretations, it means folks in Chaco (Canyon) would have been greatly impressed by what goes on in the heavens.”