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Question for December 2008

How did Aztec people tell the time?? Asked by Northmead Junior School. Chosen and answered by Professor Anthony Aveni

The basic “unit of currency” was the day. They didn’t break the day into hours, minutes, etc. There was a “town crier” in Tenochtitlan who drummed out the time when an important civic event was scheduled to occur.

The habit of orienting entire cities astronomically became widespread throughout ancient Mesoamerica. Even the conquerors who crossed the ocean from 16th-century Spain had heard about it when they entered the Aztec capital of Tenochtitlan - modern Mexico City. One informant told the Spanish friar Toribio Benavente that a festival took place when the sun at the equinox stood in the middle of the great temple, and because the alignment was a little crooked, the emperor Moctezuma needed to pull the temple down and straighten it.

The building in question is the Templo Mayor, or Great Temple, the largest and most centrally located Aztec building in ancient Mexico City. It was thoroughly re-excavated in the early 1980s after electrical workers engaged in installing one of the city's new subway lines accidentally broke into an offertory cache of jades, decorative shells, skulls and flint knives that had been deposited there 500 years before. Once each of its seven facades was exposed, measurements of the alignments revealed that the orientation exactly permits the rising equinox sun to fall into the notch between the twin temples that once stood on the flat-topped 31m (102 ft) high pyramid.

Spanish chroniclers tell us that a royal observer situated in the plaza below carefully watched for the sun, and when it arrived there the town crier would signal the time to begin the first of the rituals of sacrifices that attended each of the eighteen months of the year.

Taken from Professor Aveni's book 'People and the Sky', 2008, pp. 141-2.

One of a series of recent children's questions on astronomy, all kindly answered in brief by Professor Aveni. The others are:-

Q. Did the Aztecs think the earth was round or flat? A. The Aztecs were not interested in the shape of the earth because they didn’t descend from the Greeks. Different cultures have different issues & that wasn’t one of them.

Q. How many planets did the Aztecs believed existed? A. We can be sure that the Aztecs recognized the motion of Venus. I think they surely were aware of Mercury, Mars, Jupiter and Saturn because all are bright & move noticeably among the stars, but we have no documents that prove the case.

Q. Do we know when the cycles of the sun, the moon and Venus will next come together? A. Venus and the sun realign every 8 years. Throw in the moon and it’s 99 years.

Q. Did they have a highest number (in their calendars/counting systems)? A. There are no really big numbers in Aztec documents. Chroniclers after the conquest say the Aztec creation periods were measured in millions of years but we can’t be sure.

Q. Did the Aztecs know of different star constellations to the ones we see today? A. The Aztecs recognized the Pleiades. They called it the Fire Drill, which was used to create new fire every 52 years. They had a Scorpion, which may have been comprised of the same stars as our own, a Ballcourt, equivalent to our Gemini and a few others are pictured that we are still trying to identify - and no doubt many more.

Q. Why were they so into Astronomy? A. If you want to anchor human and natural events together no part of the environment is more reliable than the sky. First rains may come late, flowers may blossom early, and the time a hibernating animal emerges from sleep may vary, but sky events happen with extraordinarily precise regularity. Try looking up and you’ll find out.

Q. Were the Aztec day signs related to our star signs? A. There were 20 day names — after plants, animals, forces of nature; e.g. flower, jaguar, earthquake. Ours are named after Nordic versions of the old Greek Gods.

Picture sources:-

'Town crier' image from the Florentine Codex scanned from our own copy of the Club Internacional del Libro 3-volume facsimile edition, Madrid, 1994

Photos in Templo Mayor Museum by Ian Mursell/Mexicolore

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Professor Anthony Aveni

Professor Anthony Aveni

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