Scientists found the key to accurate Maya eclipse tables

Summary

But the Maya didn’t restart their tables from any single position, per the authors, which would just make the tables increasingly unreliable; instead, they used a series of overlapping tables. Lowry and Justeson concluded that the tables must have been restarted at one of two specific earlier points before the previous table ended: the 358th new moon (i.e., the most reliable overestimate of the overall length of the eclipse) and the 223rd new moon (the most reliable underestimate). “The traditional interpretation was that you run through the table, eclipse by eclipse, and then you rebuilt the table every iteration,” said Lowry. “We figured out that if you do that, you’re going to miss the eclipses, and we know they didn’t. They made internal adjustments. We think they’d restart the table midway. When you do that, you go from having missed eclipses to having none. You would never miss an eclipse. So it’s not a calculated predictive table, it’s a calculated predictive table plus adjustments based on empirical observations over time.” “This is the basis of true science, empirically collected, constant revision of expectations, built into a system of understanding planetary bodies, so that you can predict when something happens,” said Lowry. “But here it’s coded deeply within a religious system. Their rituals were fundamentally connected to astronomy and astrology. There’s this group of people over the course of 1,000 years—through war, through collapse, through famine, through external conquest—that have maintained observational records, every five or six months, of eclipses. It’s not that the Maya made their calendar more accurate. They made their calendar continue to be accurate, which is very cool.” DOI: Science Advances, 2025. 10.1126/sciadv.adt9039 (About DOIs).