How Did Maya Temples Align With the Stars?

The Maya built their temples, observatories, and ceremonial complexes with deliberate astronomical alignments to the rising and setting of the sun, the moon, the planets, and the bright stars. From the Caracol observatory at Chichen Itza to the E-Group complexes of Uaxactún, Tikal, and Copán, the Maya architectural tradition integrates precise alignments to celestial events with the ritual calendar of the daykeeper. The alignments allowed the daykeeper to calibrate the Haab’ solar year, to predict the heliacal rising of Venus, to mark the solstices, the equinoxes, and the zenith-passage days, and to set the date of royal accessions and ritual bloodletting.

This page surveys the principal Maya astronomical alignments of the temple tradition, the most important sites, and the way the alignments were tied to the Maya calendar system and the ritual year.

The Caracol observatory at Chichen Itza

The Caracol at Chichen Itza is the most ambitious astronomical structure in the Maya area. The building, a circular tower atop a rectangular platform, was constructed in the Late Classic period (c. AD 800–900) and renovated in the Postclassic (c. AD 1000–1200). The Caracol has three upper windows that frame the western horizon, and the windows are aligned to:

The heliacal rising of Venus as Morning Star (the most important Venus event in the ritual calendar).
The setting of the Pleiades (in late April / early May).
The setting of Capella (in late April / early May).
The setting of Jupiter and Saturn on key dates in their synodic cycles.

The Caracol’s alignments have been the subject of extensive astronomical and archaeoastronomical research. The most widely cited study, by Clive Ruggles and Nick Saunders, has shown that the Caracol’s upper windows frame the western horizon at azimuths consistent with the setting of Venus (the most important), Capella, the Pleiades, Jupiter, Saturn, and the sun at the solstices. The Caracol is, in this respect, a sophisticated multi-target observatory, and it is the most carefully documented Maya temple astronomical alignment.

The Caracol was also the site of ritual activities tied to the Venus cycle, including the way (Lords of the Night) cycle and the k’atun ceremonies. The Caracol is, in the Postclassic period, a major ritual structure, and it is tied to the Itza dynasty of Chichen Itza.

The E-Group complexes

The E-Group is the most common astronomical complex in the Maya area, attested at over 50 sites from the Middle Preclassic (c. 600–400 BCE) through the Late Classic. The E-Group consists of:

A small pyramid to the west.
A long platform to the north.
A viewing platform at the eastern edge.

The E-Group is aligned to:

The sunrise on the equinoxes.
The sunrise on the solstices.
The sunrise on the zenith-passage days (the days when the sun passes directly overhead at local noon).

The E-Group is attested at Uaxactún, Tikal, Copán, Quiriguá, Naranjo, Calakmul, and many other sites. The E-Group is the most common astronomical complex in the Maya architectural tradition, and it is one of the earliest, with examples dating to the Middle Preclassic.

The E-Group at Uaxactún is the type-site, and its alignments have been the subject of extensive study. The Uaxactún E-Group is aligned to the sunrise on the equinoxes (when the sun rises due east, viewed from the western pyramid), the solstices (when the sun rises to the north or south of the platform), and the zenith-passage days (when the sun rises at an intermediate point). The Uaxactún E-Group was, in this respect, a calendar-checker that allowed the daykeeper to verify the date of the solstices, the equinoxes, and the zenith-passage days.

The E-Group at Tikal

The E-Group at Tikal, called the “North Acropolis,” is one of the largest and most carefully constructed. The Tikal E-Group is aligned to the sunrise on the solstices, the equinoxes, and the zenith-passage days, and the structure was rebuilt several times during the Preclassic and Classic periods. The Tikal E-Group is also tied to the dynastic history of the city, with the k’atun and baktun markers of the dynasty being recorded on stelae erected in the E-Group.

The Tikal E-Group is, like the Uaxactún E-Group, a calendar-checker, but the Tikal structure is much larger and more elaborate, with a long platform that frames the sunrise on multiple days. The Tikal E-Group is a major ritual structure, and it is tied to the political and religious life of the city.

The E-Group at Copán

The E-Group at Copán is one of the most carefully constructed and the most thoroughly studied. The Copán E-Group is aligned to:

The sunrise on the equinoxes.
The sunrise on the solstices.
The sunrise on the zenith-passage days of Copán (30 April and 13 August).

The Copán E-Group is, in this respect, a calendar-checker for the specific latitude of Copán, and the structure is tied to the agricultural year of the Copán Valley. The Copán E-Group is also tied to the dynastic history of the city, with the k’atun markers of the dynasty being recorded on stelae erected in the E-Group.

The zenith-passage days and the 260-day Tzolkin

The zenith-passage day is the day of the year on which the sun passes directly overhead at local noon, casting no shadow from a vertical stick. The zenith-passage day is a function of latitude, and it occurs twice a year in the tropics:

At Copán (latitude 14.85° N): 30 April and 13 August.
At Tikal (latitude 17.22° N): 23 May and 12 August.
At Chichen Itza (latitude 20.68° N): 20 May and 22 July.
At Quiriguá (latitude 15.27° N): 28 April and 14 August.

The two zenith-passage days define the agricultural year: the interval between them is the period when the sun is north of the latitude, the time of planting and early growth; the period outside is the dry season. The 260-day Tzolkin is sometimes argued to have been calibrated to the zenith-passage cycle, with the 260-day half-cycle corresponding to the interval between the two zenith-passage days at Copán (30 April → 13 August = 105 days; 13 August → 30 April = 260 days). The 260-day half-cycle is, in this respect, a function of the tropical year and the local latitude.

The zenith tubes of Xochicalco

The zenith tubes of Xochicalco (a Central Mexican site with strong Maya influence in the Epiclassic period, c. AD 600–900) are vertical shafts that admit sunlight only on the day of the zenith passage. The shafts are designed to admit a vertical sunbeam into a chamber below, and the daykeeper could use the shaft to determine the date of the zenith passage with high precision. The Xochicalco zenith tubes are a more sophisticated version of the E-Group, and they attest to the spread of Maya astronomical knowledge into Central Mexico in the Epiclassic.

The Xochicalco zenith tubes are aligned to the latitude of the site (approximately 18.8° N), and the shafts are constructed with an inner surface that admits a sunbeam only when the sun is within 0.1° of the zenith. The shafts are, in this respect, a high-precision instrument for the determination of the zenith passage.

The Venus alignments

The planet Venus — alternately the Morning Star and the Evening Star over a 584-day cycle — was the most carefully tracked body in the Maya sky, and the Maya built several structures with Venus alignments:

The Caracol at Chichen Itza frames the heliacal rising of Venus as Morning Star.
The E-Group at Uaxactún is sometimes read as framing the heliacal rising of Venus at specific times in the 584-day cycle.
The inscriptions of Palenque record the heliacal rising of Venus on key dates, and the Temple of the Cross at Palenque is argued by some scholars to be aligned to the Venus cycle.
The inscriptions of Copán record the heliacal rising of Venus in the reign of K’inich Yax K’uk’ Mo’, and the Temple of Venus at Copán is a Venus cult building.

The Venus cycle is tied to the Dresden Codex Venus Table, which allows the daykeeper to predict the heliacal rising of Venus to within a day over a 481-year span. The Venus cycle is also tied to the warfare and sacrifice of the Classic period, with the first-station Venus being a time of warfare and bloodletting.

The Capella alignments

The star Capella (Alpha Aurigae) is one of the brightest stars in the Maya sky, and several Maya structures are aligned to its heliacal rising:

The Caracol at Chichen Itza frames the setting of Capella in late April.
The E-Group at Uaxactún is sometimes read as framing the heliacal rising of Capella.
The inscriptions of Palenque record the “3 stars of the Tortuguero” as a possible reference to Capella, the Pleiades, or some other asterism.

Capella’s heliacal rising occurs in late April / early May in the Maya area, and the alignment is tied to the agricultural year (the start of the rainy season in some highland communities). The 819-day cycle of Caracol and other Late Classic sites is sometimes argued to be tied to the Capella cycle, with the 819-day cycle being a multiple of the Capella-zenith-passage cycle.

The solstice alignments

The solstices — the longest and shortest days of the year — are framed by several Maya structures:

The E-Group at Uaxactún is aligned to the sunrise on the solstices.
The Temple of the Inscriptions at Palenque is aligned to the sunset on the winter solstice.
The Temple of the Cross at Palenque is aligned to the sunset on the summer solstice.
The Castillo at Chichen Itza is aligned to the sunset on the equinoxes and the solstices, with the famous serpent-shadow effect at the equinoxes.

The solstice alignments are tied to the agricultural year and the ritual calendar, with the solstices being the times of the major agricultural ceremonies. The solstice alignments are also tied to the Maya creation mythology, with the solstices being the times of cosmic renewal.

The equinox alignments

The equinoxes — the days of equal day and night — are framed by several Maya structures:

The E-Group at Uaxactún is aligned to the sunrise on the equinoxes.
The Caracol at Chichen Itza is sometimes read as framing the equinox sunset.
The Castillo at Chichen Itza is aligned to the sunset on the equinoxes, with the famous serpent-shadow effect at the spring and fall equinoxes.
The Temple of the Inscriptions at Palenque is aligned to the sunset on the equinoxes.
The Temple of the Cross at Palenque is aligned to the sunset on the equinoxes.

The equinox alignments are tied to the agricultural year and the ritual calendar, with the equinoxes being the times of the planting and harvest ceremonies. The equinox alignments are also tied to the Maya creation mythology, with the equinoxes being the times of cosmic balance.

The lunar alignments

The Moon is framed by several Maya structures:

The Caracol at Chichen Itza frames the lunar standstill positions (the extreme positions of the moon’s rising and setting on the horizon).
The E-Group at Uaxactún is sometimes read as framing the major lunar standstill.
The Temple of the Inscriptions at Palenque is aligned to the sunset on the lunar standstill.

The lunar standstill is a 18.6-year cycle in which the moon rises and sets at the extreme positions on the horizon. The cycle is tied to the Maya lunar series and to the Dresden Codex eclipse table, which uses the 405-lunar-month cycle to predict eclipses.

The Pleiades alignments

The Pleiades are aligned to several Maya structures:

The Caracol at Chichen Itza frames the setting of the Pleiades in late April.
The E-Group at Uaxactún is sometimes read as framing the heliacal rising of the Pleiades in May.
The Temple of the Cross at Palenque is aligned to the setting of the Pleiades in late April.
The Temple of the Sun at Palenque is aligned to the rising of the Pleiades in late May.

The Pleiades’ heliacal rising occurs in mid-May in the Maya area, and the alignment is tied to the agricultural year (the start of the rainy season in some highland communities). The Pleiades are tied to the 260-day Tzolkin in modern K’iche’ ritual, with the Tzolkin being the patron of the Pleiades.

The Orion alignments

The Orion’s Belt (the three stars of the belt of Orion) is aligned to several Maya structures:

The Caracol at Chichen Itza frames the setting of Orion’s Belt in late May.
The Temple of the Inscriptions at Palenque is aligned to the setting of Orion’s Belt in late May.
The E-Group at Uaxactún is sometimes read as framing the setting of Orion’s Belt.

The Orion’s Belt alignment is tied to the Maya creation mythology, with the three stones of the Maya creation being identified with the three stars of Orion’s Belt. The Orion’s Belt is also tied to the Xibalba underworld, with the three stars being the entrance to the underworld.

The temple orientation and the Maya calendar system

The temple orientations and the Maya calendar system are tightly coupled. The E-Group complexes, the Caracol, the Castillo, and the Temple of the Inscriptions are all tied to specific dates in the Haab’ solar year, the Tzolkin sacred almanac, and the Long Count. The daykeeper could use the temple orientations to:

Verify the date of the solstices, the equinoxes, and the zenith-passage days.
Calibrate the Haab’ solar year against the tropical year.
Predict the heliacal rising of Venus, Mars, Jupiter, Saturn, Sirius, Capella, and the Pleiades.
Set the date of royal accessions, warfare, and sacrifice.

The temple orientations and the calendar are, in this respect, parts of a single system that links the Maya architectural tradition to the Maya astronomical tradition and the Maya ritual calendar.

The role of the ah k’in in the temple alignments

The ah k’in (or aj q’ij in modern K’iche’) was the daykeeper, the ritual specialist who maintained the almanacs and the astronomical tables. The ah k’in was responsible for:

Observing the heliacal rising of the planets and the bright stars.
Calibrating the eclipse tables against the actual eclipses.
Predicting the eclipses for the coming months and years.
Selecting the day for royal rituals, planting, and naming ceremonies.
Reading the almanacs and the prognostications of the 260-day cycle.

The ah k’in would have consulted the temple alignments when performing these duties, and the alignments were, in this respect, part of the ah k_in’s ritual toolkit. The Bonampak murals document the ah k_in in the act of consulting the almanacs and the astronomical tables, and the Palenque inscriptions document the ah k_in in the act of performing the royal rituals.

The astronomical tradition in the Postclassic period

The Postclassic period Maya communities, including the Itza of Chichen Itza and the K’iche’ of the highland kingdoms, continued the astronomical tradition of the Classic period. The Madrid Codex preserves almanacs tied to the synodic periods of Jupiter and Saturn, and the highland K’iche’ of Q’umarkaj maintained a tradition of astronomical observation. The Caracol at Chichen Itza was renovated in the Postclassic period, and the building is a key source for the Postclassic astronomical tradition.

The Postclassic period astronomical tradition is documented in the colonial-era Yukatek sources, including the Books of Chilam Balam and the Relación de las Cosas de Yucatán of Diego de Landa. The sources preserve the 260-day Tzolkin, the 365-day Haab’, the Venus cycle, and the eclipse tables, and they attest to the continuity of the Maya astronomical tradition from the Classic period through the colonial era.

Sources

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