The Ancient Maya Used The Dresden Codex to Predict Solar Eclipses with Impressive Accuracy

Today, astronomers are able to predict a solar eclipse to the minute using sophisticated computer programming that combines Newton’s laws of motion with the positions and speeds of the Earth and moon, plus data on their orbits and inclination. Ancient Maya daykeepers used ink-drawn tables etched on the bark of fig trees.

In a paper published in Science Advances, researchers explain how the Maya were able to keep track of solar eclipses with such impressive accuracy, revealing evidence for developments of lunar theory from as early as 350 C.E.

Ancient Maya and Advanced Systems

Indigenous civilizations living in Mexico and Guatemala had two calendars – a civil calendar of 365 days and a shorter “divinatory” calendar of just 260 days.

The latter was referred to by specialists (called “daykeepers”) to determine the fates of individuals based on the date that they were born. This divinatory calendar came to be associated with the different phases of the moon by around 500 B.C.E.

The Ancient Maya may have had large libraries and an advanced writing system, but very little remains today. Indeed, only four texts are known to have survived, the oldest (and best preserved) of those being the Dresden Codex, which dates to around 1200 C.E.

The Dresden Codex is an astronomical document approximately 3.5 meters (about 11 feet) long and folded like an accordion, according to the Library of Congress. Amongst the ritual and divination calendars is a table that can be used to predict the next solar eclipse.

While historians have previously suggested eclipse prediction was its intended purpose, researchers writing in Science Advances say it was originally designed to be a general lunar calendar table.

Read More: Everything You Should Know About Lunar Eclipses

Tracking The Phases Of The Moon

The team came to this conclusion using math and a historical database of solar eclipses, finding the total number of days included in the table (11,960) more readily lines up with the 260-day calendar than it does with the cycles of eclipses that would have been visible to the Maya people between 350 and 1150 C.E.

Essentially, the number of days (11,960) neatly divides by 260: 11,960 ÷ 260 = 46

The paper’s authors also note the number of lunar months in the table (405) and compare it to the number of nodal passages, which play an important role in determining when an eclipse will occur. The average length of 405 lunar months is 0.11259 days shy of 11,960.

In contrast, 69 nodal passages are, on average, 1.67486 days shy — a figure almost 15 times as high. This led the researchers to conclude the table was more likely to have been designed to track the phases of the moon than to predict upcoming solar eclipses.

A Series Of Overlapping Tables

The other big question is how exactly the Maya were able to retain such high levels of accuracy when it came to making predictions. According to the new paper, it was achieved by adopting a system of overlapping tables.

Instead of starting a new eclipse table after an old table ends (as had previously been thought), the daykeepers often reset the eclipse table to one of two earlier points on the previous table. This tended to be at 358 lunations (or months) or 223 lunations. According to the researchers’ calculations, four “resettings” at 385 months occurred for every one at 223 months.

“Restarting an eclipse table at these intervals, and at these ratios, would have enabled daykeepers to reset the table reliably for a few millennia,” the researchers add.

The researchers believe that after approximately three cycles of 405 months, the daykeepers would have been able to observe a “fairly uniform pattern” that would enable them to create “a general framework by 453 C.E.” As such, they concluded, “it is plausible, therefore, that eclipse tables much like that of the Dresden Codex could have existed by around 550 C.E.”

Read More: Where Is Tulum and Why Was It So Important to the Ancient Maya?

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

• This article references information from the recent study published in Science Advances: The design and reconstructible history of the Mayan eclipse table of the Dresden Codex
• This article references information from the Library of Congress: The Dresden Codex