Pyramid of the Moon from the Pyramid of the Sun in Teotihuacan, Mexico
Photo: Natalie Dreier/Cox Media Group National Content Desk
Photo: Natalie Dreier/Cox Media Group National Content Desk

Aztecs, Mayans marveled at eclipses — and predicted them with precision

Astronomers across the ages have looked up to the skies and marveled at eclipses.

Using different numerical systems, the Aztecs and the Mayans observed eclipses and could predict with precision when the next one would occur. In fact, they could have predicted Monday’s solar eclipse with small margins of error, experts say.

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Anthony Aveni is a retired professor from Colgate University and author of many books on archaeoastronomy, including “In the Shadow of the Moon: The Science, Magic, and Mystery of Solar Eclipses.” According to Aveni, the Aztecs used to say they designed the founding of the city of Tenochtitlán — where modern-day Mexico City now sits — to coincide with an eclipse in 1325.

Photo: Natalie Dreier, Cox Media Group National Content Desk

“It’s a way of saying, ‘That’s when our empire began,’ connect that with the beginning. (It’s) probably not true,” he said, but saying the city’s foundation coincided with an eclipse helped give it more importance.

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The Aztecs registered many eclipses, and it’s possible their calendar stone depicts the death of the sun god Tonatiuh at the hands of an eclipse monster, said Susan Milbrath, curator emeritus of the Museum of Natural history in Florida, in a recent New York Times special section about eclipses.

The Mayans also left a record of their astronomical knowledge in books known as codices, especially in the Dresden Codex. The book now resides in Germany and is one of only four codices to survive Spanish colonial officials’ burning of the books, Aveni said.

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This codex has a famous chart of eclipses that suggests the Mayans “were watching the sky every bit as carefully as the Babylonians,” who might have been the first to keep a record of a total solar eclipse, Aveni said.

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Religion, everyday life and science were deeply connected for the Mayans, who used a vigesimal — or 20-based — numerical system for their calculations. Instead of seven days, for instance, the Mayan week had 20, which corresponded to the number of fingers and toes a person has. They used this system to calculate everything from child gestation to the movement of celestial bodies.

This is an example of “scientific cultural diversity,” Aveni said. “The Mayans had this religious, ritual dictate that any cycle in heaven had to fit perfectly with the cycles of the human body, and other cycles that we don’t pay attention to.”

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The Mayans were way ahead of their time, Aveni said, and “we tend to put them down, to say it’s superstition, but they were doing things quite comparable to what we say we know about eclipses.”

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Something most of us can agree on, Aveni said, is that when watching an eclipse, “we all stop what we’re doing, we see something unusual … and we remember that we all did it at the same time.”

“It unifies cultures,” he said.

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Watching the eclipse in Central Texas

Monday’s solar eclipse, dubbed the Great American Eclipse, will be seen from Oregon’s coast near Salem to Charleston, S.C. The next one in the U.S. will not occur until April 8, 2024, when one is expected to start in Mexico, passing through Texas and Maine, and reaching Canada.

Austin will only get to view a partial eclipse Monday.

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