EQUINOCTIAL SUN AND ASTRONOMICAL ALIGNMENTS IN MESOAMERICAN ARCHITECTURE: FICTION AND FACT

Abstract

Archaeoastronomical studies carried out during the last decades in Mesoamerica have demonstrated that civic and ceremonial buildings were largely oriented on astronomical grounds, mostly to sunrises and sunsets on certain dates, allowing the use of observational calendars that facilitated the scheduling of agricultural and related ritual activities. One of the deeply rooted but unfounded ideas is that many alignments recorded the Sun's positions at the equinoxes. By examining such proposals and analyzing their methodological flaws, I argue that they are not based on reliable and objectively selected alignment data, but rather derive from the preconceived significance attributed to the equinoxes. The most likely targets of the near-equinoctial orientations were the so-called quarter days, which occur two days after/before the spring/fall equinox and mark mid-points in time between the solstices. Considering that the astronomical alignments dominate extensive parts of the built environment, they must have played an important role in religion, worldview, and political ideology. Therefore, only a correct identification of their celestial referents, a prerequisite for any convincing interpretation of their meaning, underlying intents, and observational practices employed, can contribute to a proper understanding of some prominent aspects of architectural and urban planning in Mesoamerica.