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date: 26 July 2021

The Moon and Planets Among the Incas and Other Pre-Hispanic Andean Peoplesfree

The Moon and Planets Among the Incas and Other Pre-Hispanic Andean Peoplesfree

  • Mariusz ZiółkowskiMariusz ZiółkowskiCenter for Precolumbian Studies, University of Warsaw


Although the Inca state (ca. 1200–1572 ce) was called the Empire of the Sun, the Moon was, in some respects, an equally important divinity in the official state cult. The regulatory function of the phases of the synodic cycle of the Moon in different kinds of social activities, especially those framed in calendrical systems but also military campaigns, is well documented. As far as the orientation of architectural structures is concerned, the researchers focus their attention almost entirely on the position of the Sun. However, a more accurate analysis of two well-known sites—the caves of Intimachay and Inkaraqay—may provide evidence of their function as observatories of the lunar 18.6-year cycle. Those results may confirm the hypothesis, presented some years ago, that the Incas had elaborated a rudimentary method of predicting lunar eclipses.

The determination of the exact role of Venus and other planets in the Inca worldview encounters a serious limitation: in contrast to Mesoamerica, in Tahuantinsuyu and the Andes, there are no important “first-hand” sources such as the calendrical-astronomical data of the Maya or the Aztecs. Only Venus seems to have enjoyed a cult of Pan-American range. The morning appearance of Venus was apparently related to the puberty initiation rites of male adolescents, while its appearance as Evening Star seems to have been closely symbolically related to the Inca sovereign and his military activities. Putting aside the information available on Venus and its cult, there is an almost complete lack of data on the other planets.

Another problem must be considered: To what extent did the Incas inherit their knowledge from their predecessors, the Chimus, or even earlier cultures?


  • History of Ideas about Planets and Planetary Systems


The aim of this article is to present some of the astronomical concepts of the Incas. But who were the Incas? They were an ethnic group that built an empire in the central Andes and formed the dynasty that ruled the empire.

At the time of its greatest expansion, in 1530 ce, the Inca state, called Tahuantinsuyu, stretched over a territory of more than one million square kilometers, populated (according to the most plausible modern estimates) by 10 to 14 million inhabitants. Its territory covered, partially or completely, six current republics of South America: Peru, Bolivia, Ecuador, Colombia, Argentina, and Chile. It stretched from the Pacific coast to the tropical forest, and from the Andamayo river in present-day southern Colombia to the Maule river in central Chile (Fig. 1).

Figure 1. Map of the Inca empire.

Tahuantinsuyu had a complex infrastructure, a road network about 40,000 km in length, and a system of administration and control constituted by administrative-religious imperial centers that, throughout this immense territory, represented the centralized power of the Inca capital, Cusco.

The Inca people as such inhabited, in the 16th century, the territories of certain provinces of the modern department of Cusco, Peru, and themselves represented only about 3–5% of the total population of the empire. In the peripheral provinces of the empire the Incas constituted the upper stratum of the administration and the political, military, and religious classes, although there were also some specialized groups of Inca colonists (Szemiński & Ziółkowski, 2015, 2018).

The Inca worldview and cult developed over several centuries. If the Incas’ account of themselves in the 16th century is accepted, their mythology had its origins in Tiahuanaco (Tiwanaku), possibly during the period called by archaeologists the “Middle Horizon,” between ca. 500 and 1000 ce.

It is necessary, however, to clarify that one should not and cannot consider everything Andean as “Incaic.” Even in the period of maximum territorial expansion of the Inca state, and the greatest influence of the “metropolitan” Inca culture, other regional ethnic cultures functioned in parallel, with their own magical-religious systems, which in some respects were significantly different from the Inca models, as in the case of the Chimus of the north coast of Peru.

From the 16th century onwards, after the Spanish Conquest in 1532, the Inca cosmology (and, in general, other Andean cosmologies) was transformed through a dynamic process of interaction with the teachings of the Catholic Church, and also elements of European popular culture introduced by the newcomers. For these reasons, what is known today of the popular and rural traditions, especially in regard to astronomical concepts, doesn’t reflect in detail, and without foreign influences, the situation of the time of first contact in the 16th century, and even less those of the pre-Hispanic imperial doctrine elaborated by the Inca elites.

When dealing with the subject indicated in the title of this article, three important factors which influence (and limit) our hope of analyzing the Inca (and other Andean) concepts concerning the Moon and the planets must be borne in mind.

The first is that, in contrast with Mesoamerica, in Tahuantinsuyu and the Andes, there are no important “first-hand” sources as the calendrical-astronomical data and calendrical annotations of the Maya, or the Aztec calendar codices. Monographic treatises by colonial authors about Inca astronomy and calendars are also lacking.

The sources comprise relatively scarce and disorganized pieces of information, scattered in different Spanish chronicles devoted to indigenous Andean cultures in general. In addition, those data were compiled, in most cases, without very much care or criticism.

The second point is that when discussing the Moon and the planets in an Andean context, scholars project their own understanding, in which the celestial bodies belong to the domain of astronomy in the sense of current European science. In the Andean case, the classification was somewhat different and more inclusive, in the sense that it included everything relating to the Heavens (Hanan pacha). In such a way, both astronomical phenomena (according to our classification) and meteorological ones constituted a single group.

For this reason, the concept of the Lord of Thunder (Illapa) included both the planet Venus and a constellation representing the sling—possibly the tail of Scorpius (Eyzaguirre, 1956), as well as meteorological phenomena, such as storms, rain and thunder, and even geological objects such as oddly shaped stones, considered as projectiles thrown by the divinity.

Finally, a third, very important aspect: in Inca cosmovision (and in social as well as ceremonial practice) there was a clear and quite sharp division, at all levels, between masculine and feminine. The Moon was a female divinity, in charge of a priestly body composed of women. As the Spanish chroniclers were male and did their research on the Inca and Andean traditions mostly among men, there is very little information about the traditions preserved and managed by women (Ziółkowski, 1997, pp. 75ff.).

The Moon in the Andean Worldviews

Although the Inca state was called the Empire of the Sun, the Moon was, in some respects, equally important as a divinity in the official state cult:

They recognized in the Moon divinity, guided by the same reason that moved them to respect the sun; this is because of its admirable beauty and beauty and because of the great profits it causes in the world. They imagined her as a woman, and such was the statue they had in the temple of the sun; which was in charge of women who made office as priestesses; and when it was brought out, they carried it on their shoulders.

(Cobo, 1964 [Bk. XIII, Chap. VI], p. 158, author’s translation)

As the chronicler testifies, the cult of the Moon oversaw an exclusively female priestly body, headed by the Coya (Quya), the principal wife of the sovereign Inca. In such a way the Moon was considered as the wife of the Sun, and the Sapan Inca–Coya couple represented on a terrestrial level the celestial couple of these celestial bodies (Fig. 2).

Figure 2. Idols of the Inkas: Inti, Uana Cauri, Tambo Toco, Pacari Tambo.

This intimate Moon–Coya relationship was manifested in several ceremonial activities. For example, the mummies (or representations?) of the Coyas were placed in front of the image of the Moon in the main Inca temple of Coricancha in Cusco (Silverblatt, 1987). According to the Inca religious concepts, the dead Coya (or rather, one of her spiritual components) was going to accompany the Moon. This concept is documented in the story of the funeral ceremony of Mama Occlo, the mother of the sovereign Huayna Capac. The different phases of those funeral and commemorative ceremonies lasted for almost three and a half years (more exactly, 42 months), including a war of an apparently ritual character (Szemiński & Ziółkowski, 2015, pp. 174–175; 2018, pp. 232–233). At the end of this period, “They made a bundle of Mama Occlo and put it in her house and painted a moon in the place where she was, as to say that that this lady was going to the sun her father and that she is another moon and her like (. . .)” (Betanzos, 2004 [1551 Part I, Chap. XLIV], p. 224, author’s translation).

Another important relationship seems to be between the Moon and the terrestrial waters, both with the rivers, and with the sea, named Mama Cocha (Mama Qucha). This bond is clearly seen in the ceremonies of citua and mayocati (Ziółkowski, 1987, 1988, 2015, pp. 373ff., pp. 416–418). In this context the location of two famous temples of the Moon (apart from the Coricancha enclosure) is significant:

The temple located in the district of Pumac Chupan in Cusco, near the confluence of the Tullumayo and Huatanay rivers, where the main part of the “mayocati” ceremony took place. In the same place (perhaps inside the temple of the Moon) the ashes of sacrifices burned in Cusco throughout the year were kept in a special structure.

In Coati Island, on Lake Titicaca, the mythical place of “birth of the Moon and its ascent to heaven in the company of other stars” (Ziółkowski, 1997, pp. 76–77).

Finally, it’s worth dedicating some lines to the dark spots on the Moon:

For the spots of the moon they said another fable simpler than that of the dogs (. . .): they say that a she-fox fell in love with the Moon, and when she wanted to take hold of it, the moon embraced her, and stuck to himself, and that from this the spots were made . . .

(Garcilaso, 1963 [1608, Part I, Bk. II, Chap. XXIII], p. 74, translation Garcilaso, 1987, p. 118).

The female sex of the animal considered is rather unusual, because as highlighted by the Inca Garcilaso twice, it was a female fox, and not a male fox, as might have been expected considering the female character of the Moon. This could refer to the somewhat androgynous aspect of the Moon, which is manifested in some ethnographic data (Urton, 1981, pp. 80–81).

This is some of the scarce information available about the ritual aspects associated with the Moon and its role in Inca worldview. As already mentioned, this lack of data is due in large part to the gap in this aspect of Inca mythology and ritual, which was controlled by women. On the other hand, the regulatory function of the phases of the synodic cycle of the Moon in different kinds of social activities is better documented, especially those framed in calendrical systems.

Figure 3. A native Andean astrologer, who studies the sun, the moon.

The Inca Calendar: Luni-Solar or Luni-Sidereal?

The imperial calendar, which facilitated the coordination of administrative, economic, and religious-ceremonial functions of importance to the Inca, was not the only time-measuring tool used in Tahuantinsuyu, due to the ecological and cultural diversity of the empire (Fig. 3).

The metropolitan Inca calendar, adapted to the ecological, cultural, and ethnic realities of the Cuzco valley, is best described in sources. Some doubt exists even here, including the fundamental question of whether this was a solar calendar, with 30-day months, or a luni-solar calendar, or, perhaps, a luni-sidereal one (see Bauer & Dearborn, 1995; Urton, 1981, 2017; Ziółkowski, 1987, 1988, 2014, 2015; Zuidema, 1982, 2014).

Most of the evidence points to the idea that this was a luni-solar calendar composed of 12 synodic months calculated from one new Moon to the next (first visibility of the Moon following the new Moon in the western sky), similar to those of many other cultures, from the New as well of the Old World. Such a cycle consists of approximately 354 days, or ca. 11.25 days less than the solar tropical year. A system of adding an intercalary 13th lunar month to adjust the calendric system to the solar cycle had to be introduced. A model of correlation of such a calendric cycle with the Julian Calendar, for the late pre-Hispanic and early colonial periods (ca. 1500–1572 ce) was first proposed by Mariusz Ziółkowski and the astronomer Robert Sadowski (Ziółkowski & Sadowski, 1982–1984, 1989) and recently re-elaborated in collaboration with the astronomers Tomasz Bulik and Marek Cieślar (Ziółkowski, 2015, pp. 562ff.).

As all the months were synodic lunar, all ceremonies of the annual cycle necessarily had to do with the phases of the Moon. The periods of new and full Moon were considered especially propitious for offerings and sacrifices. It should be noted that in the programming of all the ritual activities, there is a marked tendency to carry out the main rituals and/or offerings in the period between the first visibility of the Moon after the conjunction until the 21st or the 22nd of the synodic cycle.1 On the other hand, in the following period of the waning Moon, until the new Moon, offerings or ceremonies should, apparently, be avoided. This tendency can be observed particularly in lunar feasts, such as “citua” (sitwa) or “mayocati” (mayuqati), as well as in primarily solar ones, like Inti Raymi or Capac Raymi (Qhapaq Raymi) (cf. Ziółkowski, 1987, 1988, 2015).

The regulatory importance of the phases of the Moon is clearly seen in agricultural activities. This aspect is principally known not so much through historical sources, but mostly on the basis of ethnographic fieldwork among contemporary Andean rural populations.

Gary Urton, in his well-known study of the worldview of the community of Misminay (Cusco), has analyzed the theme of the phases of the Moon, associated with the concepts of Pura (Animated) and Wañu (Inanimated). Another term commonly mentioned by Urton’s informants was that of “cuscan” or “chaupi,” in reference to the crescent or fourth quarter.

The period between the two extremes, of Pura and Huañu (Wañu), represents the change of “proportional” relationship between the Animated and the Inanimated—of particular importance is the moment of equilibrium between the two, called cuscan. It must be emphasized that “cuscan” does not connote any sense of direction of future changes. The subsequent movement can order changes in any (or no) direction (Urton, 1981, p. 84). From the astronomical perspective, “cuscan” corresponds then to the period between the crescent quarter and the fourth quarter; approximately to the 7th and 21st day of the lunation, respectively.

On the base of the data provided by his informants, Urton proposed the general scheme of the connection between the phases of the Moon and the periods of sowing of different cultigens:

Crescent moon period, from the new Moon to the full Moon: sowing of cultigens whose “productive” parts grow on the surface of the field (e.g., corn, beans, and wheat).

Waning moon period, from the full Moon to the new Moon. Sowing of plants whose “productive” parts grow under the surface (potatoes, oca, and olluco).

In contrast, Urton’s informants never referred to an association between the phases of the Moon and the timing of harvest (Urton, 1981, pp. 84–85).

It should be noted, however, that slightly different concepts were documented in other parts of the Andes. For example, in Jauja, the most propitious period for the planting of potatoes is between the crescent and the full Moon, but not during the latter and not during the waning Moon (Tillman, 1997, pp. 39–49).

It seems that in Inca times a similar and even more elaborate and complex practice of association of agricultural activities and the synodic lunar cycle was functioning. Probably other lunar phenomena, such as its passage by the zenith, were taken into account (Zuidema, 1981).

The relationship between the phases of the Moon and other biological cycles, in particular human and animal fertility, is very poorly documented, probably due to the aforementioned “information restriction.” There is only data to indicate that invocations were addressed to the Moon at birth (Arriaga, 1968, p. 214); whereas information by the chronicler Guaman Poma seems to refer to an association with the female puberty rites related to the menstrual cycle (Guaman Poma, 1615/1616, fol. 257 [259]), but this relationship is not confirmed in the available lexicographical material.

Tom Zuidema’s Theory of a “Sideral Lunar Calendar” or “Quipu-Calendar” in Cusco

Late professor Tom Zuidema, a distinguished researcher of Inca culture, was an advocate of a thesis about the existence of yet another type of Inca calendar, the so-called stellar lunar calendar or quipu-calendar (Zuidema, 1977, 1981, 2011, 2014). As mentioned elsewhere (Ziółkowski, 2014b, 2015, pp. 297ff.), in a nutshell, this hypothesis is based on the assumption that the 328 sacred places, so-called huacas, found in the environs and around Cuzco, corresponded to a cycle of 328 days/nights (Fig. 4).

These 328 nights are supposed to represent:


An equivalent of 12 sidereal lunar months of 27⅓ nights each.


An approximate length of 11 synodic lunar months, with a difference of 3½ days.


An approximate duration of the period of visibility of the Pleiades, while the leftover 37 days (corresponding to the difference between the solar year and the 328 nights cycle) will represent the “ideal” duration of the period of invisibility of the Pleiades (Zuidema, 1982, 2011).

Figure 4. The quipu-calendar model, according to R.T. Zuidema.

Detailed critiques of this concept have been presented elsewhere (Nowack, 1998; Sadowski, 1989; Ziołkowski, 1989; 2014, pp. 845–847; 2015, pp. 297–316). The main weakness of Zuidema’s hypothesis is that no historical source explicitly mentions the existence of a 328-day/night cycle. This number has not been registered either in the few quipus of astronomical function, which have been investigated (Urton, 2001, 2017), nor in the supposed Inca calendar textile, investigated by Urton (2007).

The Moon, War, and Politics

The lunar cycle coordinated many other social activities, among them military actions. This fact was realized by the Spaniards during the siege of Cuzco in May 1536, when the Incas, under the command of Manco Inca, tried to recover the capital occupied by the Spaniards and their indigenous allies. The Incas launched the main attack on the city on the night of May 5 to 6, 1536, as the full Moon was supposed to be particularly propitious for military purposes. During the following days of struggle, they managed to corner the Spaniards in some buildings around the main square of the city. But, suddenly, the Inca army withdrew, because the new Moon arrived, a period considered inappropriate for warfare (Anónimo, 1968/1934 [1539], p. 531). This greatly contributed to the final victory of the Spaniards over Manco Inca’s army (for more details see Szemiński & Ziółkowski, 2015, pp. 243–246; 2018, pp. 311–314; Ziółkowski, 1985, pp. 159–161; 1997, pp. 81ff.; 2015, pp. 480–485). The belief that the period of the full Moon is particularly advisable for certain kinds of activities, not only military ones, but also those of ceremonial-political character, was deeply rooted among the Incas and other Andean peoples. As an example, it seems particularly significant that even in 1557 ce, these considerations had an apparently decisive influence on the planning of the different stages of the negotiations and the departure of Prince Sayri Tupac from the Inca redoubt of Vilcabamba to the territory controlled by the Spaniards. First, the consultation with the Inca deities, carried out by Sayri Tupac in Vilcabamba, took place, according to the Spanish informants, on the day of “Our Lady of September,” on September 8. In 1557 this Julian date corresponded to the 14th or 15th day of the month of Coya Raymi, that is, to the full Moon. Furthermore, during this month, rituals of cleansing and certain forecasts for the coming year were performed.

Likewise, the departure of Sayri Tupac from Vilcabamba (October 7, 1557), his arrival in the city of Andahuailas (November 5, 1557), as well as his triumphal entry into Lima/Los Reyes (January 5, 1558) occurred during the full Moon (or a few days after it; see Ziółkowski, 2015, pp. 375ff., 617; 2016, p. 207).

Lunar Eclipses

Eclipses, in general, were described as “the death of the Sun and the Moon.” It is remarkable that the Inca, considered to be mostly Sun worshippers, feared lunar eclipses more than solar eclipses. The former were considered as the beginning phase of the collapse of the universe:

When a lunar eclipse took place, seeing the moon become dark, they thought that she was ill, but if it disappeared altogether, they said she was dead and would fall from the sky and kill everyone beneath and that the end of the world would come. In great terror, when an eclipse of the moon began, they sounded trumpets, horns, and drums, and all other instruments they possessed, to make a great noise. They tied up all the dogs, both large and small, and gave them many blows, to make them call and yell to the moon; for, according to a certain fable they recount, the moon was fond of dogs, owing to a service they had done her, and they hoped that, when she heard them cry, she would be sorry for them, and awake from the sleep caused by her sickness (Garcilaso, 1963 [1608 Bk II, Chap. 23], translation according to Garcilaso, 1987, pp. 118–119).

The interpretation of the causes of the phenomenon was as follows:

They used to say than when a lunar eclipse started, a lion or a serpent attacked it to tear it to pieces. Therefore, when it started to eclipse they were yelling and beating dogs to make them bark and howl. Armed men were standing and blowing horns, beating drums, yelling fiercely, shooting arrows and throwing javelins in the direction of the moon, menacing with their spears as if they wanted to hurt the lion and the serpent. They used to say that in this way they were threatening out and frightening them, making them unable to tear the moon. Some of our priests used to predict the eclipses to liberate them from these absurdities.

That is how the Spaniards acquired their reputation as great sages. There is a great admiration for us among them because we predict the eclipse with such an accuracy that we warn them not only about the night when it will take place, but even about the time of the beginning and end and the part of the moon that will be eclipsed (Cobo, 1964 [Chap. VI], pp. 158–159, author’s translation).

Does it mean that the Incas were unable to predict lunar eclipses? The answer is ambiguous: probably yes, they were capable of it, but the prediction of eclipses in pre-Columbian America could not have involved a level of accuracy comparable to that in the Old World. The Incas did not possess a system of dividing time into hours, nor any adequate mathematical apparatus. Therefore, in speaking about the prediction of an eclipse scholars are referring to rudimentary methods for predicting the night when it would occur, rather than the precise hour or the magnitude. As in other cultures, such knowledge must have been of a very secret nature, and it is no wonder that members of the Inca elite would not inform everyone of such matters (Ziółkowski & Lebeuf, 1993).

The most interesting, even if somewhat indirect, proof in support of this hypothesis comes from the diary of Don Diego Rodriguez de Figueroa, in which he recounts the events of his diplomatic mission to the neo-Inca state of Vilcabamba, in May 1565 (Rodriguez de Figueroa, 1910). From this description, compared to the tables of lunar eclipses of the time, one can draw the conclusion that the Inca ruler, Titu Cusi Yupanqui, took advantage of the partial eclipse of the Moon that took place on the night of May 14 to 15, 1565, to appease the excessively aggressive attitude of his troops and achieve a peace agreement with the Spaniards (Ziółkowski, 2014b, pp. 915–916; Ziółkowski & Lebeuf, 1993).

Any system of forecasting eclipses, although rudimentary, must be based, however, on observations of the movement of the Moon to define the ecliptic longitude of the node. Do testimonies exist of such observations on the part of the Incas, not only of the phases, but of the movement of the Moon?

Horizontal and Zenithal Observations of the Moon

The problem of identifying lunar orientations is quite complicated; a summary of the state of discussion on the subject has been presented by A. César González-García (2015). Without going into details, it can be said generally that the major and minor standstills are usually considered significant lunar orientations, the former being, of course, the most important. As far as the monuments of cultural Inca affiliation are concerned, apparently only three or four cases are known cases of orientations probably associated with the major lunar standstill. Two of these are in the administrative and ceremonial Inca center of Huánuco Pampa (Peru): the ushnu platform in the center of the main square and the Inkawasi building. From the ushnu, the extreme positions of the Moon on the horizon can be observed, while in Inkawasi there are gnomonic observations in the niches of the southeast room of the structure (Pino Matos, 2004; see also Fig. 5). Unfortunately, the information provided by the author does not help in establishing the precision of such observations.

Figure 5. The inca ceremonial and administrative centre of Huánuco Pampa (Peru).

A third example of a structure possibly associated with the observation of the major lunar standstill was the observatory of Intimachay in Machu Picchu, where the phenomenon would be observed by means of the gnomonic technique; the lateral window of the structure would be used for this purpose (Ziółkowski, 2015; Ziółkowski, Kościuk, & Astete, 2013; see also Figs. 6 and 7).

Figure 6. Intimachay (Machu Picchu, Peru).

Figure 7. Intimachay, plan of the cave based on 3D laser scanning.

Finally, another case, although much more problematic, would be the cave of Cussilluchayoc (Cusco). There, the observations were also gnomonic-zenithal, that is, achieved through the use of a vertical conduit through which the light of the Moon, during its culmination and passage through the zenith, would enter (Ziółkowski, Kościuk, & Astete, 2014).

Solstice azimuths, however, also limit monthly azimuths of the Moon; they are what may be called the “central” ones, occurring roughly halfway between the major and minor standstills. At these times, when the lines of nodes of the Moon’s orbit have rotated through roughly 90° or 270° since the last major standstill, the effect of perturbation in the inclination of the lunar orbit disappears, and it is possible to define the Moon’s longitude with the greatest accuracy. This is why it is possible to assume that apparent orientations upon solstice azimuths might in fact have been used for lunar observation (Ziółkowski & Lebeuf, 1993). This could have been one of the functions of the Inca astronomical observatory of the Mirador of Inkaraqay (National Archaeological Park of Machu Picchu—Fig. 8). Here, the most spectacular phenomenon is observing the sunrise right over the Yanantin summit during the June solstice. This phenomenon is visible through both observational openings of the structure but centered in the northern one (Fig. 8). It should be noted, however, that observation with the naked eye is possible only in the initial phase of the phenomenon; once the entire solar disk is above the horizon, its glow is too blinding. One can hypothesize that, in this case, the opening was used not for horizon but for gnomonic observation, following a ray of sunlight falling on the back wall of the structure (Astete, Ziółkowski, & Kościuk, 2016/2017). The second option would be to observe the rising Moon in this very particular position.

Figure 8. The Inca astronomical observatory at El Mirador/Inkaraqay.

If the Incas were indeed able to predict eclipses, the testimony of chronicler Cobo already mentioned can be understood differently. The Incas were not so much impressed by the ability of Spaniards to predict eclipses, as they were by the precision with which they could achieve such predictions (“not only the night” . . .). In any case, it was obvious that such knowledge should be reserved only to the elite of the state.

The examples cited here appear to confirm the thesis that observations of the Moon in Incan culture were far more important than was originally believed. This subject clearly requires further research, which could lead to the revision of certain, seemingly definitive, scientific resolutions.

The Planets in the Inca Worldviews

The determination of the exact role of Venus and other planets in the Inca worldview encounters a major problem concerning terminological and classificatory order: the Quechua word coyllur (quyllur) refers to a class of phenomena that includes stars and constellations, but also planets, meteorites (and/or bolides), and comets as well as the “black constellations,” that is, the dark clouds on the Milky Way.

When analyzing data referring to the different types of “coyllur,” it turns out that the information about planets is very scarce. Apart from Venus, no proper names of any other planet are known, and the only distinction in the Quechua and Aymara dictionaries between stars and planets is that the latter are denominated as “Hatun ccoyllur” (Gonzalez Holguín, 1952, pp. 632) or “Hacha huara huara” (Bertonio, 1956, p. 369), which means “big star.” Due to this gap, if not absence in the sources, studies on this subject are very few, and they are almost absent in the main compendia that deal with pre-Hispanic Andean astronomy (see Aveni, 2003).

Only Venus seems to have enjoyed a cult of Pan-American range. Among the Incas it was known under two names: Chasca Coyllur and Chuqui Illa. As it was demonstrated, these two names probably refer, separately, to the two aspects of Venus: Chasca Coyllur, the Morning Star, associated with the Sun; while Chuqui Illa refers to the Evening Star, related to the Lord of Thunder (Ziolkowski, 1984; 1997, pp. 58ff.; 2015, pp. 102ff.).

Venus: Patron of Youth

The morning appearance of Venus was apparently related to the puberty initiation rites of male adolescents:

When putting on huaras [a type of shorts] when they [the children] are eight or ten years old, they usually have almost the same superstitions (as before the Conquest), and it has been found in this particular, as they say they used in the past, making sacrifice to Venus, who in this province, they call Huarac, and maybe this alludes the name of huaras.

(Arriaga, 1968, pp. 215–216)

Figure 9. A drawing of Guamán Poma de Ayala entitled “First chapter of the Incas.”

This association was also valid among the Incas. Venus, in its two aspects, as Evening Star and Morning Star, was considered to be the patron (and tutor) of the aristocratic youth of Cusco: “Another temple of Luzero Chasca Cuyllor, Chuqui Ylla, uaca bilícacona. There they (the auquiconas and ñustaconas, prinsepes) entered to sacrifice, as those were gods of them, of the youth” (Guaman Poma, 1615/1616, fol. 263, p. 265, author’s translation—compare Fig. 9).

The name of Chasca Coyllur, attributed to Venus in its aspect of Morning Star, presents interesting symbolic connotations: “They called [. . .] the planet Venus Chasca, ‘curly’ or ‘maned,’ from its many rays” (Garcilaso de la Vega, 1963 [1608 Part I, Bk. II, Cap XXI], p. 72). The relationship with hair has two aspects: one of a general nature, with at least some “stars” associated with the growth of hair or wool. For instance, the “black constellation” of Yacana in the myth of Huarochirí, took care of the growth of the wool of the llamas (Taylor, 1987, Chap. 29, pp. 426–427). The other aspect is more specific, and possibly refers to the “haircut” ceremony, which was part of the initiation rituals of Inca youth.

The ambiguity of Venus has several aspects, among others, the sexual one: the star is protective of youth of both sexes, according to the aforementioned fragment from Guaman Poma. In Pachacuti’s drawing he appears once to the left, with a masculine name “grandfather,” and again on the right, as “grandmother” (Pachacuti Yamqui Salcamayhua, 1993; see Fig. 10).

Figure 10. The representation of the “Major altar of the [temple] of Coricancha.”

Note that this androgynous aspect is also revealed in other phenomena associated with the “Lord of Thunder,” for example, the Rainbow. It is a concept still valid in contemporary beliefs, which consider the set of atmospheric phenomena as ambiguous in terms of their “sexual” classification. The Rainbow is imagined (sometimes) as a two-headed and bisexual serpent (Urton, 1981, pp. 88ff.).

Returning to Venus and its relation to the rites of puberty: Did this mean that the synodic cycle of the planet (584 days, on average) regulated the initiation rituals, by the association of the phases of the cycle with certain rituals? There is no explicit confirmation in this regard, an indirect indication, in the form of unclear explanations about the date of the main initiation ceremony called “huarachicu” and the undoubted difference in age of the subjects admitted to it. This seems to suggest that the “huarachicu” (Inca) could be mobile, according to a cycle of duration different from the solar year.

Venus, the Lord of Thunder, and the Inca King

The close relationship of this star with the Lord of Thunder has been mentioned by several authors and already noted at the terminological level. The second name Chuyqui illa is attributed to Venus, but also to one of the manifestations of the Lord of Thunder. This leads us to consider how the Incas (and other Andean peoples) visualized this divinity in the celestial vault:

They imagined the thunderbolt, provider of the precious water, as a man in the sky whose shape is traced by stars with a mace in his left hand and a sling in his right hand, dressed in bright clothes which gave the spark to the lightning flash as he pulled the sling causing thunder when he wanted rain to fall [. . .].

(Cobo, 1964 [1653 Part II., Bk. XII, Chap. XII; Bk. XIII, Chap. VII], p. 78, pp. 160–161, author’s translation)

There is no clear identification of this divinity with a specific constellation or group of stars to date. Venus, however, in its aspect as Evening Star, represented the “Thunderbolt of Hanan Pacha,” that is, the projectile launched by the Thunder god with his sling.

The Lord of Thunder and His Role in the Inca Wars

As explained in previous studies, the sovereign Inca benefited from a “ritual brotherhood” with the Lord of Thunder and, particularly, with one of his aspects, Chuqui illa (Ziółkowski, 1984, 1997, pp. 58ff.). It’s worth remembering that Chuqui illa was both:


one of the manifestations of Thunder and, as such, protector of the Inca sovereign in its military activities; and, at the same time,


the star Venus as “Evening Star.”

This leads us to consider a more practical problem. Was there a direct relationship between periods of visibility of Venus as “Evening Star” and the military campaigns led personally by the Inca sovereign? As a logical consequence, the presence of the Inca in the battlefield should have taken place, preferably, during the period of visibility of Venus as “Evening Star,” when the “divine protector of the Inca” was present in the sky for a period of approximately 263 days (Fig. 11). On the other hand, during the visibility of Venus as “Morning Star” (or in the period of invisibility during the conjunctions of Venus with the Sun), so, roughly during the remaining 321 days of the Venus synodic cycle, the Inca should have abstained from going to war, delegating the command of the army to his subalterns. This is, of course, a working hypothesis that should necessarily be checked by the analysis of the dates of the military Inca campaigns.

Figure 11. The ritual attitude of the Inca sovereign at war: “As the Ynga fights with his enemy from above his litter.”

The facts that permit investigation of this problem are only what the first Spanish chroniclers of the time of the Spanish Conquest could obtain as first-hand information about the campaigns of the last Inca sovereigns, and particularly those of Atahualpa and Manco Inca. These few data have been summarized in Table 1, where the dates of contests were compared to the phases of the synodic cycle of Venus, with an additional information about the presence (or absence) of the Inca in the battlefield.

Table 1. Association between the presence of the Sapay Inca on the battlefield and the conditions of Venus visibility (The corresponding astronomical calculations made by Robert M. Sadowski)



The Inca on the battlefield

Venus elongation

Venus visibility

1532, November 16

Atahuallpa performs a ritual (fasting) in the baths near Cajamarca, from at least several weeks, while his generals fight against the army of Huascar



Morning Star

1533, end of December

Appointment of Manco Inca as sovereign.

The Inca leads an expedition against the forces of Quisquis.


ca 36°

Evening Star

1536, May 5-6

Siege of Cusco - general attack of the forces of Manco Inca against the Spaniards and their indigenous allies. The Inca remained in Calca, performing rituals



Morning Star

1538, November

Manco Inca victory over the forces of captain Villadiego.

The Inca takes personally part in the battle



Evening Star

As noted in the case of the four events that have been dated with relative precision, the military activity of both Incas seems to manifest some association with the visibility cycle of Venus: the Inca personally attended the battle only when Venus was visible as “Evening Star,” while he was absent (delegating the effective command of the army to his “generals”) during periods of visibility of Venus as “Morning Star.” The scarcity of facts (only four cases), however, does not allow any statistical analysis confirm with acceptable probability the existence in the Tahuantinsuyu of a ritual-war cycle similar—toutes proportions gardées—to the “Venus wars” of the Maya.

In other words: it is not possible to assess conclusively the association presented between the two types of Inca behavior (active or passive) in a campaign war and the phases of the synodic cycle of Venus, nor if said association is the effect of a deliberate decision, triggered by ritual-religious considerations. This does not mean that the hypothesis is, for that reason, uninteresting. From the statistical point of view the association can be due to chance. It is also to worthwhile to observe that if, in three of the mentioned cases, the Inca had the possibility to decide to go or not go to the battlefield, it was not exactly like that in the battle in 1538 of Manco Inca’s personal guard against Spanish infantry headed by Captain Villadiego. The latter tried to attack the Inca by surprise and he had no choice but to defend himself. It is noteworthy, however, that at this precise period, the Inca was already directing a military campaign, and Venus was then visible as Evening Star.

There are other examples that show the relationship between the ritual activities of the Inca king and the Venus cycle, although unfortunately not with certainty. Pedro Sarmiento de Gamboa mentions an interesting 16-year cycle (equal to 10 cycles of Venus) related to the education of the future Inca sovereign, Tupac Inca Yupanqui: “[Pachacuti Inca Yupanqui] raised (. . .) [his successor son, called Tupac Inca] locked in the house of the Sun more than sixteen years, and did not let him see anybody, apart from his teachers and instructors (. . .)” (Sarmiento de Gamboa, 1965 [1571, Chap. 43], p. 247, author’s translation).

Other interesting information comes from the history of Pachacuti Inca Yupanqui, whose relationships with Chuqui Illa has been noted. The chronicle of Juan de Betanzos relates the tradition preserved in the clan of that sovereign, according to which the military campaigns of Pachacuti Inca Yupanqui would have been separated by periods of 20 years of rest, and that the sovereign would then have died at the age of 120 years. It is obviously a symbolic duration of human life, since the same source indicates that Pachacuti Inca Yupanqui lived to be 89 or 90 years old, which seems more realistic. So why would that symbolic age of 120 years have been attributed to him? The chronicler does not say anything about this, but the only recourse is to speculation. First, 120 years make six times 20 years, the ideal length of separation between military campaigns. Second, 120 solar years of 365 days make a good approximation of 75 synodic Venus cycles of ca. 584 days.

The role of Venus in the religious concepts of the Incas deserves a more detailed study, which is beyond the limits of this article. As an example, another interesting coincidence: on the day of the execution of Atahualpa, on July 26, 1533, Venus was in inferior conjunction with the Sun and therefore was invisible in the sky of Cajamarca (see Ziólkowski & Sadowski, 1992, pp. 276–282, tables XV and XVI). Did this coincidence influence the idea, apparently shared by Atahualpa himself, of his possible quick resurrection (Pizarro, 1986 [1571, Chap. 11], p. 63)?

Other Planets

There is an almost complete lack of data on the planets other than Venus, and even information on Venus is scarce. The Inca Garcilaso states categorically that: “They only noticed these three planets [Sun, Moon, Venus] because of their size, splendor, and beauty, and ignored the four other planets” (Garcilaso de la Vega, 1963 [1608 Part I, Bk. II, Chap XXI], p. 72); Cieza is less extreme in his opinion about that subject, as he argues that, apart from the Sun and the Moon, the Incas also observed the planets: “they have great account with the moon and with the planets [. . .]” (Cieza, 1986 [1553, Part I., Chap. LXV], p. 272, author’s translation). Unfortunately, he does not offer details in support of this statement.

The only historical data that could be interpreted in the sense of “prognosis,” that is, as the description of a divination system based on the observation of the planets, is a myth about the celestial signs which announced the “Deluge” (evidently, in its Andean version):

In the province and people of Ancasmarca, which is five leagues from Cusco, in the part of Antisuyo, they have the following fable: They say that when the deluge was to come, a month before the rams (llamas) showed great sadness and that during the day they did not eat and at night they were looking to the stars, the shepherd in charge asked why are they so sad, to which they replied that they looked at that conjunction of stars; in agreement to which the world will end with water (deluge).

(Molina “El Cusqueño,” 2008 [1575], fol. 5r–5v, p. 144, author’s translation)

The importance of this myth lies not only in underlining once more the important role in the Andean worldview of predictions based on astronomical observations, but in the very nature of the phenomenon mentioned: a “conjunction of stars.” Obviously, the stars themselves have fixed positions in the sky, and cannot form occasional and variable conjunctions; for that reason, it more likely refers to the movement of one or more planets over the background of the constellations. If the authenticity of the myth is accepted, this would be the only Andean story about divination based on the observation of the planets. But it may also be an invention of the chronicler, based on the memory of the famous European prophecy of the “Universal Flood,” predicted for February 21, 1524. The prognosis was based on an uncommon number of conjunctions of the planets in the zodiacal sign of Pisces, and not only caused serious concern at the time, as shown by several pamphlets, drawings, and so on, but also produced significant social unrest, especially in Germany (Beer, 1967, pp. 220–221; see also Hartner, 1967). It is worth underlining that astrological concepts were widespread and discussed by the literate people of those times, and some of them practiced astrology, for example, the famous cosmographer Pedro Sarmiento de Gamboa (Brosseder, 2010).

The attribution to the representatives of Andean cultures of certain European concepts has been noted in the text of the Jesuita Anónimo (cf. endnote 1). A similar approach appears in a recent study by Subhash Kak, in which the author presents another analysis of the famous “Yupana” or Inca abacus, represented in one of the drawings of the chronicler Guaman Poma de Ayala. Kak elaborates a fairly complex model of how to use such an instrument and suggests that the numbers represented in the object drawn by Guaman Poma refer to synodic cycles of Jupiter, Saturn, Venus, Mars, and Mercury (Kak, 2014). Without entering into a detailed discussion of this hypothesis, it should be noted that the calculation system proposed by Kak is totally arbitrary and lacks any support in the historical sources related to Andean cultures. In addition, this author uses, in support of his reconstruction, a document of very dubious authenticity, the Exsul Immeritus Blas Valera Populo Suo.2 In synthesis, the problem of the observation of planets in the pre-Hispanic Andes remains largely unresolved.

Moon and Planets in the Non-Inca Cosmovisions

Among the most valued contributions to the topic, one that stands out is the classic study conducted by Gary Urton on the Inca cosmovision, based in the first place on the anthropological research he performed in the village of Misminay, in Cusco, between 1975 and 1977. The excellence of this study (Urton, 1981) and its wide diffusion, as well as the numerous references made by other authors, meant that in a somehow automatic and uncritical way, all the data concerning pre-Hispanic Andean cosmovisions began to be analyzed according to the model proposed by Urton. The denomination of the “Misminay model” in the literature meant that important divergences between—for example—the astronomical concepts of the coastal and Andean peoples were forgotten, something that is quite evident if the environmental and climatic differences between the coast and the Andean highland region are borne in mind (Moore, 2004, p. 21). It must be pointed out that Urton himself later published an interesting preliminary study on the astronomical-calendrical knowledge of the coastal cultures (Urton, 1982), stressing the clear divergences with respect to highland models. Unfortunately, this paper did not have the same impact and diffusion as his work on Misminay and the cosmovision of the Quechua peoples. Urton (1982) cites profusely the chronicler Antonio de la Calancha, one of the few colonial authors interested in the cosmovisions of the coastal peoples. The astronomical-calendric references of Calancha’s chronicle, though relatively scarce, are of great interest, as they refer to cultures that were contemporary with the Incas, namely those situated on the northern coast and part of the Chimu-Moche tradition:

The Indians of Pacasmayo and the rest of the valleys worshiped the moon as their main and superior deity, because it predominates over the elements, breeds the food, and causes disturbances in the sea as well as thunder and lightning. At a huaca nearby its shrine, which they called Sian, meaning “house of the moon,” they considered it more powerful than the sun, because the latter did not appear at night, whereas the moon could be seen both at day and at night; and even at this the absent are unfortunate; and also because it eclipsed the sun frequently, whereas the moon was never eclipsed [. . .]. During eclipses of the Sun, they dedicated festivities to their deity, celebrating its victory, while during eclipses of the Moon they would cry while performing sober dances, thus manifesting their grieving and accompanying the darkness with the mourning.

(Calancha, 1638, Vol. 4, Book II, Chap. II, pp. 12–13, author’s translation)

The Moon had its own temples, whereas the chronicler does not mention any places dedicated to the Sun:

Sian was the temple of the moon and on the first day of a new moon, the greatest sacrifice was performed, constituted of food, drink, animals and birds. Blinded by their religion, they would sacrifice their children, then considering them as deities and worshiping their clothes as relics; so great is the blindness of these idolaters and the oppression in which the Devil keeps them. In the many chambers of this huaca, as if they were their own domicile, there were demons who retained their lordship even after those valleys were populated by the Spaniards [. . .].

(Calancha, 1638, Book II, Chap. IV, p. 29, author’s translation)

The period when the conjunction of the Moon occurred was particularly marked by, among other acts, the sacrifice of children:

The Indians of the plains believed that when the Moon did not appear during those two days, it would travel to the outer world to punish dead thieves; a vice that was hated the most. They sacrificed five-year-old children to the moon, who were placed on colored cotton and were accompanied by chicha and fruits.

(Calancha, 1638, Book II, Chap. II, p. 13, author’s translation)

The Moon had “chosen women” or acllas, devoted to its service: “They had virgins [like our nuns] who dedicated themselves to the moon, imitating those in Cusco, devoted to the sun, who were called acllascas” (Calancha, 1638, Chap. II, p. 18, author’s translation).

Judging from the excerpt that follows, at least some of the places of worship to the Moon were located on hills:

Out from distant hills and huacas in Guadalupe (such as the hill nearby Chocope, and that called La Canpana, among others), I heard loud noises from drums, musical instruments of the Indians, in somber, sad and afflicted tones. Some who have paid attention to this noise and careful of this singularity, have warned that this sad rumour and somber drumming happens during the nights of moon conjunction and when asked about the cause, older Indians say that the Demons are weeping, and that it was on a night of conjunction and new moon when they were worshiped and were offered sacrifices, but when the Virgin Mary banished them, they were no longer worshiped or served.

(Calancha, 1638, Chap. IV, p. 29, author’s translation)

Some stars were venerated along with the Moon, especially Orion’s Belt (then called “The Three Marys”):

They had two stars called Pata as their deities, which we called the Marías, and many Indians tell (and many perhaps believe it) that the star in the middle is a thief, a malefactor and a villain, whom the moon wanted to punish so it sent along the two other stars to grab him (that is the meaning of Pata) and take him where he would be eaten by vultures. These buzzards are represented by the four stars below the Marías, while other seven stars represent the memory of the guilt and the exemplary punishment inflicted to the thief.

(Calancha, 1638, Book II, Chap. II, p. 13, author’s translation)

Calancha, however, does not provide any direct information about the observation of planets by the peoples of the north coast.

Using Calancha’s evidence, as well as the anthropological work conducted by Gillin (1947) with Huanchaco fishermen, Urton proposed the following directions for future studies:

From our study, we are led to hypothesize that, along the Peruvian coast, the orientations incorporated in public architecture might include the rising and setting points of the Pleiades, the Southern Cross, Orion’s Belt, and the zenith and nadir sun (all of which will change with the latitude).

(Urton, 1982, p. 245)

Combining the ethnographic data with information in the chronicles, Urton proposed an approximated reconstruction of the coastal calendar, based on stellar observations. The starting and ending dates in this calendar correspond, respectively, to the heliacal rising and the heliacal setting of the Pleiades. These dates delimited the main season of fishing activities (from late November to June) and the beginning of the agricultural season. During the Colonial Period, and within a process of religious syncretism, the practical observation of the sky might have been—at least partially—replaced by Christian festivities: the Feast of Saint Andrew the Apostle (November 30), the Feast of the Cross (May 3), and the Feast of Saint Peter (June 29) (Urton, 1982, p. 237).

To evidence of the astronomical-calendric knowledge of the northern coastal societies, one must add the limited data from the Aymaras of the Bolivian Altiplano. The problem of the characteristics of the Aymara knowledge in the matter and its similarities, but at the same time differences, from those of the Incas, has been dealt with elsewhere (Ziólkowski, 2015, pp. 316–317). To these observations can be added the only exact reference to the proper names of other planets than Venus: Mars—Nina—kampu (fire tarantula) and Jupiter—Jillikhana (bright light) (Eyzaguirre, 1956, pp. 94–95). Unfortunately, the author of the text does not specify where or in what conditions he obtained this information.

The Archaeological and Iconographic Evidences Related to Moon and Planets from Pre-Incaic Cultures

The information on the Andean cultures for which there are some historical references can be used for the interpretation of the archaeological record. For those cultures with no direct historical data, historians must confine themselves to the study of iconography and the orientation of some monumental structures.

In theory, the more interesting data, particularly iconographic, should come from three cultures: Tiahuanaco, Nasca, and Moche.

Surely the most investigated from this point of view (a least, for a time) was the Tiahuanaco culture, in particular one of its masterpieces, the Gate of the Sun. Unfortunately, what has been written on this subject is far from representing an acceptable academic level (compare by the way of the famous work of Edmund Kiss: Kiss, 1937). With such antecedents, it is not surprising that modern scholars prefer to avoid astronomical issues in their research in the field of Tiahuanaco iconography.

Another very controversial issue is that of the calendric-astronomical interpretation of the famous Nasca geoglyphs and part of the iconography of this culture. The topic has aroused much discussion and controversy, the state of the advances on the subject has been presented in another text (Ziółkowski, 2009). With the theme of the figurative geoglyphs comes the problem of iconography, which brings a major obstacle: the representation in Nasca art of motifs associated, clearly and unequivocally, to celestial bodies is, at first glance, very limited, if non-existent (Proulx, 2006, pp. 159–160; Giuseppe Orefici, personal communication, April 2009).

Finally, the most advanced and most reliable studies seem to be those on the astronomical representations, among others of the Moon, in Moche iconography (Benson, 1985; Olsen Bruhns, 1976). The female divinity of the Moon on a half-moon shaped raft and the famous “lunar animal” (Fig. 12), identified by C. Mackey and M. Vogel as the wildcat known as colocolo (Oncifelis colocolo) (Mackey & Vogel, 2003, pp. 326–329—Fig. 12) are the best examples.

Figure 12. Moche Moon Animal.

To these evidences of the astronomical-calendar knowledge of the coastal societies, one has to add another, relative to the horizontal observations of the Sun with calendric purposes. This function has been proved by recent archaeological-astronomical studies by Iván Ghezzi and Clive Ruggles at the Chankillo site in the Casma Valley (Ghezzi & Ruggles, 2007). It is worth underlining that Chankillo—contemporary to the early phases of the Nasca culture (around 230 bce)—is, so far, the sole monument on the Peruvian coast which may without doubt be considered as a precise astronomical observatory (Fig. 13). Though Chankillo is mainly dedicated to the observation of the Sun, Ghezzi and Ruggles have identified possible lunar alignments, suggesting that ceremonies relating both to the Sun and the Moon might have taken place at the full Moon nearest the December solstice. These alignments occur on buildings that are either ceremonial or defensive, posing questions about the relationship of the lunar cycle with war (Ghezzi & Ruggles, 2011).

Figure 13. Chankillo, Casma Valley (Peru).


As already emphasized at the beginning of this study, the facts related to the role of the Moon and the planets in Andean cultures are very scarce and cannot be compared with the extensive evidence on that subject from Mesoamerican cultures. One thing seems very clear, however. Inca cosmovision was just one of several worldviews embraced in the pre-Hispanic Andes, and the existing evidence should not be reduced to what is called “the Misminay model.” The most evident and at the same time best-documented diversions are between the cosmovisions of the Incas and that of their contemporaries, the Chimus of the north coast.

In Inca belief, it is likely that the Moon was considered to be one of the main repositories of vital energy, the “cama.” For that reason her role could, in certain aspects, surpass that of the Sun. These conclusions can be drawn by comparing the interpretations and reactions to the eclipses of the Moon and the eclipses of the Sun, respectively.

There is also some evidence, although indirect, about the possible role of Venus in the war activities of the Inca sovereign.

As far as the oldest cultures are concerned, a promising field of studies is undoubtedly the Moche iconography. Finally, the importance of Chankillo, the oldest astronomical observatory in this region of the Americas, should be highlighted. Perhaps future studies will allow scholars to provide fuller information about the function of this spectacular monument.


I am very grateful to Tristan Platt and Iván Ghezzi for their comments on and help with the linguistic drafting of this text.

Further Reading

  • Bauer, B. S., & Dearborn, D. S. P. (1995). Astronomy and empire in the ancient Andes. Austin: University of Texas Press.
  • Ruggles, C. (Ed.). (2014). Handbook of archaeoastronomy and ethnoastronomy. New York: Springer Science+Business Media.
  • Ziółkowski, M. (2015). Pachap unancha: El calendario metropolitano del estado Inca. Arequipa, Peru: Ediciones El Lector-Sociedad Polaca de Estudios Latinoamericanos.
  • Zuidema, R. T. (2011). El Calendario Inca: Tiempo y Espacio en la Organización Ritual del Cuzco; la Idea del Pasado. Lima, Peru: Fondo Editorial del Congreso del Perú-Fondo Editorial Pontificia Universidad Católica del Perú.


  • Adorno, R. (1998). Criterios de comprobaci6n: el manuscrito Miccinelli de Nápoles y las crónicas de la conquista del Perú. Anthropologica PUCP, 16, 369–394.
  • Anónimo. (1968). Relación del sitio del Cuzco y principio de las guerras civiles del Perúh asta la muerte de Diego de Almagro 1535–1539. In Biblioteca Peruana (Vol. 3, pp. 513–612). Lima, Peru: Editores Técnicos Asociados S.A.
  • Arnold, D., & Espejo Ayca, E. (2006). On drinking cups and constellations: Some relations between Aymara astronomical and textual practices in Qaqachaka ayllu (Bolivia). Journal of Latin American Cultural Studies, 15(2), 183–213.
  • Arriaga, P. J., de. (1968). Extirpación de la idolatría del Pirú. In Biblioteca de Autores Españoles (Vol. 209, pp. 191–277). Madrid, Spain: Ediciones Atlas.
  • Astete Victoria, F., Ziółkowski, M., & Kościuk, J. (2016/2017). On Inca astronomical instruments: The observatory at Inkaraqay—El Mirador (National Archaeological Park of Machu Picchu, Peru). Estudios Latinoamericanos, 36/37, 9–25.
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  • Avila, F. de. (1966). Dioses y hombres de Huarochiri. Narración quechua recogida por Francisco de Avila (J. M. Arguedas, Trans.). Lima, Peru: Instituto de Estudios Peruanos.
  • Bauer, B. S., & Dearborn, D. S. P. (1995). Astronomy and empire in the ancient Andes. Austin: University of Texas Press.
  • Beer, A. (1967). Astronomical dating of works of art. Vistas in Astronomy, 9, 177–223.
  • Benson, E. P. (1985). The Moche moon. In D. P. Kvietok & D. H. Sandweiss (Eds.), Recent studies in Andean prehistory and protohistory: Papers from the Second Annual Northeast Conference on Andean Archaeology and Ethnohistory (pp. 121–135). Ithaca, NY: Cornell University Latin American Studies Program.
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  • Calancha, Fray A., de la. (1638). Coronica Moralizada del Orden de San Avgvstin en el Perv, con sucesos egenplares en esta monarquia. Barcelona, Spain.
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  • Garcilaso de la Vega, El Inca. (1987). Royal commentaries of the Incas and general history of Peru (Vols. 1 and 2) (R. Hamilton, Trans.). Austin: University of Texas Press.
  • Ghezzi, I., & Ruggles, C. (2007). Chankillo: A 2300-year-old solar observatory in coastal Peru. Science, 315, 1239–1243.
  • Ghezzi, I., & Ruggles, C. (2011). El contexto social y ritual de las observaciones del horizonte astronómico en Chankillo. In M. Giersz & I. Ghezzi (Eds.), Arqueología de la Costa de ncash (pp. 135–154). ANDES. Boletín del Centro de Estudios Precolombinos de la Universidad de Varsovia N° 8—Travaux de l’Institut Français d’Études Andines 290. Lima, Peru: Centro de Estudios Precolombinos de la Universidad de Varsovia—Instituto Francés de Estudios Andinos.
  • Ghezzi, I., & Ruggles, C. (2014). Chankillo. In C. Ruggles (Ed.), Handbook of archaeoastronomy and ethnoastronomy (pp. 807–820). New York: Springer Science+Business Media.
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  • González Holguín, D. (1952). Vocabulario de la lengua de todo el Perú llamada Lengua Qquichua o del Inca. Lima, Peru: Universidad Nacional Mayor de San Marcos. Publicaciones del cuarto centenario.
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  • 1. It is noteworthy that his recent study of three calendar quipus of the Laguna de los Cóndores, Urton highlights the importance of the number 21 or 22 in the internal organization of these objects (Urton, 2017, pp. 63ff).

  • 2. See Laurenchich, Minelli, and Magli (2007). A strong and well-argued criticism concerning the dubious authenticity of the Exsul Immeritus manuscript has been presented, among others, by Rolena Adorno and Juan Carlos Estensorro F. (Adorno, 1998; Estensorro, 1997).