The iconography of the Mexican flag- the eagle, serpent and nopal cactus, have their roots in pre-Columbian imagery, as is well-known. What is not so well-known understood is how this pre-Columbian imagery is based on astronomy.
In the book Aztec Astronomy, the modern constellations are given pre-Columbian associations and through these associations, the origin of many religious and cultural symbols can be attributed to astronomy once again.
Below is a video that demonstrates how the symbols from the Mexican flag can be traced back to modern constellations that are given pre-Columbian associations. Lastly, the same symbols from the Mexican flag and the astronomy are identified in the Codex Yoalli Ehecatl [Borgia].
*Please press the “play” buttons to advance the video