General Aztecs Maya Tocuaro Kids Contact 22 Nov 2017/7 Movement
Text Size:

Search the Site (type in white box):

Professor Anthony Aveni

Question for August 2008

How many planets did the Aztecs believe existed? Asked by Thomas’s Prep School (Clapham). Chosen and answered by Professor Anthony Aveni.

Aztec astronomers; picture courtesy of Anthony Aveni
Aztec astronomers; picture courtesy of Anthony Aveni (Click on image to enlarge)

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 and move noticeably among the stars, but we have no documents that prove the case.

The famous observatory (‘El Caracol’) at the Mayan site of Chichen Itza; photo by Maricela González/Mexicolore
The famous observatory (‘El Caracol’) at the Mayan site of Chichen Itza; photo by Maricela González/Mexicolore (Click on image to enlarge)

One possible clue comes from the Maya, from whom the Aztecs inherited a huge body of knowledge about astronomy, calendars and maths. One of the most spectacular of all sky based events recorded in Mayan monuments happened on 20 July 690 CE; the Mayan date was 2 Cib 14 Mol in the 52-year Calendar Round (it’s interesting that the first half of this date is the position in the 260-day cycle, while the second half, the 14th day of the Month of Mol, gives the position in the 365-day year).

The ruins of the great Maya city of Palenque; photo by Ian Mursell/Mexicolore
The ruins of the great Maya city of Palenque; photo by Ian Mursell/Mexicolore (Click on image to enlarge)

Thanks to modern astronomical calculations, we know that on this night a rare planetary ‘meeting’ took place in the skies over the ancient Maya city of Palenque. It involved Mars, Jupiter and Saturn, which had been dancing about the night sky ever more closely together. The date is inscribed in several texts on plaques at Palenque’s ruiins.

Each inscription seems to imply that the three major sky gods responsible for the most recent cyclical creation of the world, which is stated in the inscriptions to have taken place at Palenque some 4,000 years earlier, were re-assembling in the sky. For the Maya this would have helped confirm in power the ruling dynasty of the time, ‘ordained by the gods’...

Adapted from Professor Aveni’s book ‘People and the Sky’, 2008, p. 171.

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. Is it true the Aztecs learned the cycle of Venus from the Maya? A. We now know that the references to Venus in calendars from Central Mexico look the same as those of the Maya. It’s likely that’s where they came from, but we have no proof.

Q. How did Aztec people tell the time? A. 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.

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.

See each answer in a little more detail in the following months...

Professor Anthony Aveni has answered 7 questions altogether:

Is it true the Aztecs learned the cycle of Venus from the Maya?

Did the Aztecs think the earth was round or flat?

How many planets did the Aztecs believe existed?

How did Aztec people tell the time?

Did the Aztecs know of different star constellations to the ones we see today?

What sort of gadgets did the Aztecs have?

Why did houses have no windows?

Comment button

Here's what others have said:

Mexicolore replies: To quote from Aveni’s earlier work ‘Skywatchers of Ancient Mexico’ (1980, p.15) ‘Mesoamerican priests conceived of a layered universe, each stratum containing one category of celestial body. Above the layer of the earth, the moon travelled its heavenly course. Above this moved the clouds, the stars, the sun, Venus, comets, and so on, with the male-female creator god occupying the thirteenth and uppermost layer. The underworld consisted of nine divisions, if we count the earth as the first, stacked in an orderly fashion below earth. This view is quite in contrast with both the geocentric [earth-centered] and heliocentric [sun-centered] views of the universe which evolved in the classical Western world.’ Hope this helps!