An ancient ‘horizon calendar’ comes into view over Mexico City
The New York Times reports: Long before Europeans colonized North America, the Indigenous peoples in the valley where Mexico City would later arise may have followed a natural solar calendar that was so accurate it accounted for leap years. The “horizon calendar,” proposed in a new study, relied on natural landmarks in the valley’s rugged eastern mountains, and was kept in sync with the astronomical year by a temple atop a sacred volcano. The system may have been used by…