Introduction to Archaeoastronomy



(Colorado Plateau Series, Book 8)



© 2018

<<<featured on my Amazon Author’s Page:>>>

(Volume VI of XV)

Notice to the reader: The authenticity of this text is accurate and based on reliable interpretative research correlating to, say, a standard endorsed by the National Park Service. This miniseries features a concise narrative based on the indigenous culture of the Colorado Plateau Province featuring the Ancestral Puebloans. The information is divided into fifteen subtopics so that readers have the option to peruse individual chapter material or select and specific topics that appeal to one's interest. Because this text can be read in such a fashion, there is overlapping subject material throughout this abridged compendium but presented in more detail as befits the topic of the selected volume. Except where noted, the research for the text is based on a variety of observations. Therefore, entailing the academics of archaeology, anthropology, and human history, all specializing in the American Southwest. Unless otherwise specified, the collective term, "researchers" or "cultural scientists" will apply for these respective and primary academic disciplines. 

 Volume I A Comprehensive Primer (p.5)
 Volume II The Pecos Classification System (p.36)
 Volume III A Georitual Landscape (p.43)
 Volume IV The Utility of Pottery (p.57)
 Volume V Rock Art (p.68)
 Volume VI Intro to Archaeoastronomy (p.76)
 Volume VII Chaco Canyon Archaeoastronomy (p.93)
 Volume VIII Archeological Benchmarks (p.106)
 Volume IX Warfare and Cannibalism in the Southwest (p.121)
 Volume X The Great Drought and Diaspora  (p.155)
 Volume XI The Puebloans (p.194)
 Volume XII The Hopi People (p.216)
 Volume XIII The Zuñi People (p.225)
 Volume XIV A Time Machine Excursion (p.228)
 Volume XV The Ancestral Puebloan Homeland (p.239)

This sixth installment explores the fascinating subject of archeoastronomy, whose precise science played a pivotal role in Ancestral Puebloan cosmology and temporality. Please note key benchmark eras listed throughout this series are governed by the Pecos Classification System (PCS). The authenticity of the subject matter is accurate and based on reliable interpretative research correlating to, say, a standard endorsed by the National Park Service. Instead of footnotes, Additional Background inserts appear throughout the text. Since there are no direct quotes mentioned throughout the text, the Bibliography also attests to much of the source material for each narrative. Naturally, the author expresses personal opinions from time to time.

Prologue: Archaeoastronomy is a study of how prehistoric people comprehended the phenomena in the night sky, and specifically, stargazers who used celestial bodies and the position of select stars in their belief systems. Their cosmology included the prediction of the winter and summer solstices and the spring and autumn equinoxes. For some cultures, the study of the cosmos set its focus on various shapes represented in the Zodiac and manifested in their culture. 

With these highlights in mind, and considering archaeoastronomy is based on empirical science and precise predictions (i.e., the solstice and equinox events), some critics of archaeoastronomy’s relevance might argue the point it’s misleading to consider this discipline in the guise of a viable study of ancient astronomy solely based on how modern astronomy is considered more of a scientific discipline. In fact, archaeoastronomy crosses such a threshold of reasoning, for it considers a culture’s symbolically rich interpretation of phenomena in the cosmos. Moreover, the relevance given this cosmological notion tends to entwine with a compatible cultural discipline––ethnoastronomy. Therefore, signifying the anthropological study of skywatching in contemporary societies. In this light, archaeoastronomy is closely associated with historical astronomy, which implies using historical records of celestial events to address such subject matter. The history of astronomy also relies on recorded evidence to evaluate past astronomical practice.

And so, the credit of those, today, who have advanced the principles of archaeoastronomy, the discipline of this study has opened doors and windows not only to prehistoric cultures, but also an innovative interpretation of the night sky that is anything but a random order of starry points. Considering how the science of so-called biological time (briefly explained later in this volume), it is safe to assume contemporary researchers have learned more about the mindset of prehistoric people in the past fifty or so years than all the years leading to the present. This declaration applies to the Ancestral Puebloans of Chaco Canyon whose archaeoastronomy advances are presented in Volume 7 of this miniseries.

The Importance of Seasonal Changes: Given the import of archeoastronomy, these three questions are fundamental in asking how the science of archaeoastronomy specifically relates to the Ancestral Puebloan culture:

  1. When calculating the changing seasons, where did they search to find the advantage necessary for such precise calculations? 
  2. Who did they look for in telling them what was coming? (and)
  3. When did they know to hunt or fish or gather edible plants, or where or when to find game? 

Clearly, these astute people knew where to find these answers. They also knew when to move and where to hunt (i.e., which also correlates the concept of biological time’s impact on ancient cultures to the present). In fact, the Ancestral Puebloans denote a people with exceptional prowess who not only possessed an awareness of their temporal surroundings but were also a highly informed culture that was harmonized with the cosmos. Cosmology, in this sense, represented precise mathematics to help advance their culture. This announcement is why they looked to the heavens and studied those starry points including lunar light and shadows. The observations were mainly conducted during each changing season, for these equal quarters of the year portrayed specific insights directly relating to social and religious ceremonies that affected the Ancestral Puebloans, as well as all cultures that were influenced by the stars. The change of seasons and its influence on Ancestral Puebloan lifestyle is indeed significant as it is something momentous governing their way of life. 

Fundamentally on this point, there is order in the change. Likewise, different seasons denote different climate. In this light, the change of season can be a time for planting or a time for reaping, just as it can be a time for living comfortably with the weather or suffering from the extremes of cold and temperatures. The ability to predict the seasons––by tracking the rising and setting points of the sun throughout the year––was part of the key to their social order, survival, and reliable prediction. Since all prehistoric people had no calendars, and, therefore, had to learn what the Earth and the heavens represented to both their culture and sustainable existence, the change of seasons were always a persuasive force that coincided with their cultures and societies. Specifically, how each season affected what activities were accomplished, the clothing the people wore, the food they planted and consumed, and what was available as a natural resource at any given time of the year. Even the psychology of changing moods was important and had something to do with changing seasons, particularly the diminished light during the colder, darker months.

For these reasons, prehistoric people monitored the clockworks of the cosmos above their encampments and villages. They were perceptive observers who knew what the advancing or diminishing light of any season represented. And it follows, their primal cosmology served them well. After all, there was order in the night sky that had everything to do with a culture’s terrestrial environment and existence.

What Archeoastronomy Teaches: History teaches by revealing what has gone before. Depending on the subject matter, depends on what, if anything, we learn from the past. Regarding the tenet’s of archaeoastronomy, what we have learned from archaic and prehistoric cultures is the accurate use of reading the stars and planets, including the moon, and, therefore, basing predictions of celestial bodies and their placement in the sky. These predictions also reveal when constellations or even select stars and planets appear during certain times of the year. Indeed, most cultures throughout the world perform solstice ceremonies. Largely, the same applies to the equinoxes. At the root of these predictions, and for some of the more observant civilizations, there was a phobia applied to failing light of day. Hence, daylight might never return unless humans intervened with a preordained commemoration or an applied ceremony marking the event. For this reason, most ancient cultures built astronomical observatories in various designs such as tombs and temples, well-placed slabs of rocks, and cairns intended to align with the solstices and equinoxes. 

Today, archaeoastronomy studies these archaeological and significant global sites, and there are many places to do just that. In North America, one of the most famous sites is Chaco Canyon’s Sun Dagger petroglyph. The Chacoans constructed this site over a thousand years ago and used its precise location for the obvious purpose: predicting the changing light according to the season. Although calendars in our time mark the date is broken down into months, weeks, and days, for Chacoans, and all other ancient civilizations, the timing of the season came from above––the night sky. In fact, a direct reference was monitored at eye-level. In this case, an arc of light moving across a petroglyph panel on a select time of the year. It was, therefore, up to humans to figure a way to predict the precise timing of the celestial event.

The Magnitude Of Cyclical Time: A guiding force in observant and long practiced studies of the cosmos realized when the longest or shortest day of the year occurred or when the important spring and autumn seasons began. For the Ancestral Puebloans, theirs was a basic science concerned with temporality and the eternal, yet advanced enough to shape their culture from being merely prehistoric people. Moreover, they lived from season to season, and not just on a daily basis. A developed religious mindset about their lives and customs, knowledge of what the stars or moon predict, and perhaps possessing an understanding of the five known and visible planets in that era were fundamentally instructive and requisite for their culture. These three aspects helped prepare them for what they had to know about ordinary and important social events, which again, centered on hunting and gathering, planting, and harvesting. 

And yet, the preciseness necessary to predict seasons, even lunar eclipses, wasn’t only based on observations of celestial events or bodies. Rather, those priests, or by any similar title of higher office, put in charge of such ceremonial affairs used cyclical celestial movements to interpret the fate of society, or one assumes such a relied upon skill and practice. Like many Puebloans today, their ancestors perceive time in a singular way. For them, they believed time was cyclical, and, therefore, predictable. Since the fate of the people was somehow tied to the celestial movements these people monitored, then it must be foreseeable, as well. The most significant points of reference during the solar year, therefore, came down to the previously mentioned solstices and equinoxes and predicting the four seasonal events. In this sense, we also find the crux of archaic and prehistoric cosmology correlating to a developing culture based on the science of prediction. Hence, not guessing the outcome.

Various Nuances Of Archaeoastronomy: Archaeoastronomy finds its basis, as a cultural utility, and uses a variety of methods to base its conclusions. As an overall methodology, scrutiny of the cosmos seeks to uncover evidence of past practices. For instance, the disciplines of archaeology, anthropology, astronomy, statistics, probability, even history. Because these methods are diverse, and, therefore, relies on data from acknowledged and different sources, the problem of integrating the methodology into a coherent argument has been a long-term issue for contemporary archaeoastronomers. Essentially, there is a concern about how its regimen fills complementary niches in landscape archaeology, as well as an academic discipline known as cognitive archaeology. In short, a focus on ways archaic and prehistoric societies thought and perceived symbolic structures relevant to the physical evidence of objects they made and architectural designs that were conceived. Furthermore, cognitive archaeology refers to a material culture in the past, and how material evidence and its link to the night’s sky can reveal a larger perspective, then integrated into core beliefs (of culture) about the cycles of nature. The astronomy practice of the Mayan civilization and its relationship with agriculture is an ideal example. Other examples pertinent to Ancestral Puebloan archeoastronomy practices that have brought together ideas of cognition and landscape incorporate studies of the cosmic order embedded in the roads of their settlements (such as the Chaco Canyon compound). These studies entail the mathematics used in constructing their village layouts, including all that pertains to said villages.

Naturally, the science of archaeoastronomy can be applied to all cultures and all time periods, regardless. True, the significance of the cosmos and its starry points may vary from culture to culture; however, when examining ancient cosmological beliefs, there are scientific methods that can be applied across time and culture. Thus, finding a means to balance the social and scientific aspects of archaeoastronomy’s principles.

Observing The Clockworks Of The Cosmos: The Earth’s annual orbit is the celestial master clock and denotes the common benchmark of human lives throughout the year. Years are, therefore, divided into seasons, just as calendars are segmented by months. While mechanical and digital timepieces measure intervals that divided into hours, minutes, and seconds, the rotation of the Earth on its axis (1,038 mph/1,670.4 km at the equator) decreases north or south in latitude. However, it’s the Earth's regular and rhythmic orbit around the sun (about 67,000 mph/107,826 km) that standardizes our general timeframe of reference, despite the geographic distances separating one from another or generational distances of separation from our ancestors. There is also a precise mathematics how the universe works in some noteworthy ways, including our relationship to the sun, the planets, and the stars. Indeed, everything relating to cosmology, and whatever one makes of it from a cultural or religious perspective, relates to our planet moving through the heavens, by orbiting around the sun (i.e., the so-called ecliptic path). This meticulous circuit also deviates less than a second from one year to the next. Moreover, the Earth processes through eight significant, yet invisible, thresholds within each orbit. These spatial milestones are, therefore, crucial to the broad subject of archeoastronomy. It follows how the point always gets back to how select times of the year mark the beginning, midpoint, and end of each annual season. Namely, equinoxes, solstices, and cross-quarters, the latter referring to a day falling approximately halfway between a solstice and equinox. These two main seasonal celestial events are merely moments shared planet-wide, as defined by the Earth’s precise tilt (23.5º and the sun's position on the ecliptic along 45º arcs (see below for more background).

For ancient civilizations that were interested, perhaps even entertained by the cyclical motion of the stellar bodies, the ability to fix these specific cusps to the nearest day was highly prized knowledge, and more than likely, sacred to their culture. With modern measurements and calculators much better accuracy is possible for determining these calculated moments. It follows how modernity’s equinoxes and solstices have become little more than annotations on occasional weather reports. As for the previously mentioned cross-quarters, they are all but forgotten select days throughout the year––despite having been patiently and patently observed and celebrated by people for scores of centuries. To the ancient skywatchers, credit is due for such science, for they refined their systems of regulating primitive calendars. They also memorialized celestial events, both cyclical and unique. Often, they relied on sunlight and shadow effects striking and passing across select targets, as well as specific building designs perfectly aligned with equinox and solstice sunrises and sunsets (as is the case for Chacoan observers). For some cultures, noting cross-quarters was equally important. Sometimes the celestial cycles of the moon, Venus, even Mars, captivated their attention. However, knowing seasonal durations and transitions were vital to success in ways to help sustain a culture’s existence (i.e., hunting migratory prey, spawning fish, planting crops, and harvesting same).

Was The Cosmology Of The Ancestral Puebloans Influenced By Others? The cultural and technological sophistication of the Ancestral Puebloans, who advanced through the centuries from say, the Pueblo II Era onward, is reflected in their interest in astronomical orientation. Of particular interest was the solar and cardinal alignment of select dwellings and kivas. At Chaco Canyon, this assertion is particularly the case. The cultural contact with the Mesoamerican societies, notably the Aztec and Mayan peoples, is plausible, for both cultures studied eclipse cycles and developed complex calendric systems. Extensive trading that existed from each of these respective geolocations also supposes the Chacoans had learned something in the bargain. Namely, advanced mathematics fostered by these particular southern latitude civilizations. Then again, is it not possible for different civilizations to cultivate their various intellects independently of one another? For some, this theory holds true. Then again, not having verbatim knowledge of the customs of the Ancestral Puebloans requires turning to their successors for key insights about ceremonial importance associated with cosmology. In this case, comprehending the significance of relating cycles of the sun and moon. Moreover, ethnographic reports centered on the planning of the winter solstice ceremony indicate strong desires to have the date coincide with the full moon. 

The Hopi People, for example, synchronize the lunar and solar cycles over two to three years in setting their ceremonial calendar. It follows how their attention to the moon must have brought them close to observing a so-called standstill cycle. Thus, in its monthly revolution, their observance of the moon’s house represents the farthest north and south fix. Although the four season interludes (i.e., solstice and equinoxes) are based on predictive solar calculations, the lunar cycle is equally important to some observers, as well as relevant ceremonies based on lunar observations. For example, some of Chaco Canyon’s outlier dwellings are lunar aligned. Indeed, this aspect intimates a rarity of architectural design and placement throughout the world. Compare these outlier dwellings to Colorado’s Chimney Rock, near Pagosa Springs, where moon served this site’s inhabitants with another purpose: calculating the range of the moon’s declination, at its maximum. In other words, the preciseness of a lunar standstill (see below for more details). 

Other Puebloans are equally observant given the cosmological significance of the moon’s light. For instance, some view the beginning of the new year with the new lunation closest to the winter solstice. For this reason, there is a ritual of planting of prayer flags when the lunar orb is full, and most particularly, at the winter solstice. It follows how the moon’s significance in Puebloan ritual life meshes with their view of lunar cosmology, and, to the point, the duality theme in said cosmology links the sun and moon as male and female counterparts. Notably, the Sun-father and Moon-consort or sister. The Tewa Puebloan nations (i.e., Nambé Oweenge, San Ildefonso, Santa Clara, and Tesuque pueblos to mention some) also view the moon as the mask of the sun. This effort to seek the synchronization of lunar and solar cycles is duly noted.

And then there is the significance of the world’s most famous solar and lunar observation compound––Fajada Butte––Chaco Canyon’s most revered and celebrated landmark. The significance of this butte in its connection with archaeoastronomy, including the findings and theories based on the butte’s acclaimed sun dagger spiral, is nothing less than sensational. Notably, how ceremonial priests recorded the highest and lowest positions of the sun and moon, as well as the respective reflected light and shadow at the center of the spiral. The importance of such science defines the purpose of the Chacoans creating this cosmological template positioned precisely where it is. Pinpointing a lunar standstill cycle is, even more, remarkable; that is given the precise calculations that are necessary to regard moving across the face of the spiral. With the possible exception of Casa Grande’s ruins (near Phoenix), there is no other known evidence of spiral markings of the lunar standstill cycle in the Americas. Regarding Colorado’s Chimney Rock’s lunar standstill observations, they were not based on spiral drawings. Instead, the calculations were based on two towering columns of rocks. Hence, something natural the Ancestral Puebloans at the site had patiently observed centuries ago. 

Explanation Of The Lunar Standstill: In recent times, Chimney Rock has become an important stopover for those interested in lunar standstill observations. Hence, why the moon’s orbit appears to oscillate when viewed rising at different points on the horizon over a set number of years. The exact number for a complete cycle amounts to 18.6 years. At each end of its cycle, the moon appears to pause for about three years, thereby rising at the same point on the horizon before returning to its usual routine: moving back toward the opposite end of the swing. This critical pause is known as MLS, which is the abbreviation for a Major Lunar Standstill event. Chimney Rock’s site is indeed a rarity among all other archeoastronomy sites, if not altogether peerless. Its importance to the Ancestral Puebloans was also chanced upon, when Dr. J. McKim Malville, a professor of Astrophysics at the University of Boulder, demonstrated the moon would rise between the so-called Chimney Rock and Companion Rock as viewed from the Great House Pueblo on top of the site. His discovery, in 1987, demonstrated the Chacoans who maintained this observation site, that is presuming Chimney Rock was the northernmost Chacoan outlier post, were more than curious or aware of such events. Hence, the site dwellers built the Great House to mark this rare event––a revered event based on little more than a wobbling moon rising through two sentinel rocks. The most recent MLS began in December of 2004 and lasted for about three years. The next cycle will begin in 2021 or 2022 (see below for more mathematical details about MLS). While the importance of such cosmic events in our neighborhood no longer holds its appeal, as it once did for the Ancestral Puebloans, astrologers have found a great deal of interesting fodder based on MLS. For example, this website, which is one of many, demonstrates such import to its discipline: 

As for the possible explanations for the timing of the shadow phenomena in Native American culture coinciding with weather patterns, particularly in Chaco, on this matter, the science of archeology is stymied. Therefore, researchers have no answer for such a phenomena. Researchers in this field have also found nothing significant in the dates when the sun reaches the important declination +18.4 degrees. The same contention also holds true when climatic patterns affecting Chaco’s region fails to indicate these noteworthy dates applicable to consistent times of rain or other climatic events. The marking of declination +28.7º is also considered not relevant to the annual solar calendar. Thus far, the evidence points to this archaic site as a place where the cosmologically-minded Ancestral Puebloans successfully integrated on one set of spirals with one set of slabs the precise cycles of the sun and moon (for more background on this research, refer to this site:

Additional Background: At Chimney Rock, Ceremonial priests observed the moon making its complete lunar cycle across the sky over a period of 18.6 years, thereby defining the basis for calculating a lunar standstill phase. Viewed between the twin column rocks every 9.3 years, and for approximately two years such calculations obviously require long-term observations. Of course, neither the sun nor the moon stands still! Instead, what seemingly stops is the change in declination, the mathematics, of which, is described in this capsule summary: the Earth spins on its axis while the stars appear to move in circles. In the mindset of ancient cultures, it, therefore, appeared as if those starry points were more or less fixed in a greater sphere encompassing the planet. Modernity’s science, however, tells an obvious, and altogether, different account. Given how mapmakers measure places on the Earth using latitude and longitude, star mappers, so-called, measure the positions of stars (in their sphere). Notably, a measurement in right ascension (equivalent to longitude) and declination (equivalent to latitude). It follows how a local on the Earth at a latitude of, say, 45º relates to the heavens above as a declination matching this number. However, the sun and the moon do not have a fixed declination as do the stars. Here the mathematics and principle become more entailed. As the Earth annually orbits the Sun, its rotational axis is tilted at 23.5º (an approximate calculation) from the “vertical” (read, “a line perpendicular to the orbit). Concurrently, the Sun’s declination changes from +23.5º at the northern hemisphere summer solstice to -23.5º at the northern hemisphere winter solstice. In other words, in the Earth’s northern hemisphere, the sun is higher in the sky, and, therefore, visible for a longer period in June compared to December. This flip-flop of degrees’ explanation precisely defines the cause of the Earth’s changing seasons!

That said, there is more to the mathematics scenario associated with the moon. Hence, its orb also changes in declination, and with this important and distinct difference: declination changes every lunar nodal period, marking the time between successive passages through successive orbital nodes. The Moon’s nodal period is calculated at 27.212 days and what this translates to is a positive declination to a negative declination in nearly two weeks! Ergo, in under a thirty-day period the Moon’s altitude at its culmination moves from being high in the sky, too low over the horizon, then back again. This swing also happens when the Moon is due south on the meridian that defines the great circle passing through the celestial poles and the zenith of any particular location. As complicated as this relatively simple explanation sounds, there is far more detail presented on websites such as or  Suffice it to say how the lunar standstill, which denotes a polar opposite to solar and lunar eclipses, was an event wholly engaging to Archaic Era and prehistoric people. As Alexander Thom theorized in his work “Megalithic Lunar Observatories.” numerous ancient stone circles were designed to keep track of the changing positions of both the sun and the moon, merely by monitoring where on the horizon each sphere rose and set. Thom is also credited as the first archaeologist to coin the term “lunar standstill.”

Biological Time: Repercussions of the previously mentioned calculations on cosmological events (as predictions) are based on a corollary under the designation biological time. In the life sciences, this discipline relates to numerous living organisms that incorporate biological clocks governing the rhythms of behavior (i.e., where animals and plants sometimes exhibit a circadian cycle such as temperature and metabolic rate that possibly correlates with a genetic basis). Another way to describe the term is how natural life cycles and events of certain organisms function by the presence or absence of light. The reason this subject matter is even mentioned in this volume is that biological time and archeoastronomy are handmaidens of a sort; that is based on their respective and specialized disciplines. Biological time is also a unifying theory that links the timing of ancient calendars with modern scientific research. Furthermore, historical records show how the natural world is marching to an innate drumbeat that modern civilizations are just now learning to hear and discern. 

While archaeoastronomers have primarily focused on humankind’s interpretation of the cosmos from the perspectives of how they influenced storytelling and religion, from all the above we note how there are other important relationships between these celestial movements and the life cycles of plants and animals. For instance, organisms also abide by rhythms that are entrained by light. Sunlight is a perfect example that substantiates this point, for it has the greatest influence in one sense, yet the sun’s reflection off the surface of the moon is equally significant. There’s also the darkness without these forces that should be considered. That said, some animals, particularly those in marine environments, strictly follow lunar and tidal rhythms. To be sure, prehistoric and historical man was more cognizant of these controlling forces than we are today since humans in that time embraced a much closer contact with the natural world. One should also recall how these people were hunters, farmers, fishers, and shepherds. Consequently, their lives vitally depended on understanding how specific movements of the celestial bodies coincided with the availability of food. They also knew how to use changing lunar cycles. Over time, this understanding has been lost to succeeding generations. In fact, most people these days don’t plan their activities by the moon, let alone the sun; that is other than gauging the weather. (Bernie Taylor’s publication, Biological Time, is a highly recommended read and can be procured at this site:

Moments In Time––The Equinox And Solstice Events: Mentioned previously were these annual major celestial events, and here explained in more detail. 

Earth orbits the sun elliptically and simultaneously spins on its axis that’s tilted to the plane of orbit. The mathematics explain how different hemispheres are exposed to different amounts of sunlight throughout the year. Because the sun is our natural and sole source of light, energy, and heat, as well as the changing intensity and concentration of its rays are what makes the four seasons possible. These changing seasons typify the solstices and equinoxes––astronomical terms that relate to the Earth’s tilt. Moreover, solstices are the major celestial events that mark the points at which the North and South Poles are tilted at their maximum toward or away from the sun. From this explanation, it follows how the direction of the tilt is what marks the difference between the acutest daylight and nighttime hours.

Throughout the Southwest, a plethora of archaeological ruins reveal ingenious ways the Ancestral Puebloans figured out how the cosmic chronometer relates to Earth’s terrestrial clock. Certainly, Chaco Canyon’s singular compound and Chimney Rock support this claim. For instance, the explicit measurement and recording of rays passing across the face of a rock panel (a petroglyph by any other name) involve exact calculations of the sun’s movement on select days throughout the year. Hence, an accurate prediction of equinoxes and solstices. The important thing to know about both celestial events is that these marked periods of the year entail two specific moments in time. Equinoxes, for instance, happen where there’s a location on the equator and the center of the sun is observed vertically overhead. 

Given these primary celestial events, each year the equinoxes occur on March 20 or 21 and September 22 or 23. Hence, the etymology is derived from the Latin aequus (equal) and nox (night). Furthermore, around the equinox the dichotomy of night and day are equally long (that is, approximately). In short, latitudes +L and - L north and south of the equator experience nights of equal length. By comparison, a solstice is an astronomical event that also happens twice each year. That said, the etymology of the term means the sun appears to terminate its movement. The name is derived from the Latin sol (sun) and sistere, meaning what was just mentioned: standing still. What stands still, however, is the sun’s declination, that is the apparent movement of the sun’s path north or south of the equator seemingly comes to a stop before reversing its direction. Solstice can also be used in a broader sense, say, as the date (day) when such an event happens.

What’s important to note about this subject matter is how these twin benchmarks only occur when the sun's apparent position in the sky reaches its northernmost or southernmost extremes. The solstices, together with the equinoxes, are indeed connected with the changing four seasons. In some cultures, these twin celestial events are considered to start or else separate the seasons while in others they fall nearer the middle. (To learn even more about the science and mathematics behind these twin celestial events, start with this URL: and realize there are numerous other similar sites that will flood the mind with more details.)

Relevance Of The Ecliptic Plane: During the year, the Earth completes a single orbit around the sun. We, therefore, take note of this evident fact how the sun moves against a background lattice of stars, as well as throughout the year, and does so along an imaginary pathway in the cosmos (the previously mentioned ecliptic). Thus, defining the plane in which the planets in the solar system circle the sun at varying distances. This four-point summary fills in the rest of the details:

  1. Directions to the north and south ecliptic poles are at right angles to this plane. 
  2. As a common point of reference, the Zodiac describes a band of constellations running along the ecliptic. 
  3. Because the orbit of the Earth revolving around the sun takes 365.25 days, the axis of its rotation tilted at 23.5º to the line of the poles of the ecliptic is what governs the directions to the north and south celestial poles. 
  4. Polaris, the famed north star, is currently a beacon showing the direction of the north celestial pole. Like a spinning top, this axis is precessing around the ecliptic pole marking a period of twenty-six thousand years.


This summary takes us back to the equinoxes and their more technical aspects. At times when the Sun is crossing the celestial equator, day and night are of nearly equal length at all latitudes. In March, as the sun vectors northwards along the ecliptic, the vernal equinox takes place, and in September, as the sun vectors southwards, it’s the autumnal equinox. The equinoxes, therefore, denote the points on the celestial sphere where the ecliptic and equator cross and the vernal equinox is used as the zero point in measuring star coordinates. It follows how the vernal equinox defines the movement when the sun crosses the true celestial equator––the imaginary line in the sky above the equator––from south to north, which happens around March 20 or 21 of each year. For the autumnal equinox, the dates are either September 21 or 22. Like the solstices, the equinoxes have everything to do with the Earth’s orbit around the sun. Hence, there are two moments––and not whole days––of the year when the sun is exactly above the equator. At these times, neither pole tilts toward the sun. These moments are called equinoxes. Equally, and because the Earth’s axis tilts toward its orbital plane, sometimes the northern hemisphere is tilted toward the sun, and sometimes the southern hemisphere tilts toward the sun. The change isn't severe, but it’s enough to be the cause of the four seasons. When the north is tilting toward the sun, warmer weather is generally the case in the north. Conversely, when the south is tilted toward the sun, then the southern hemisphere usually experiences warmer weather. 

Given this Astronomy 101 course information, the next question is: Why do equinoxes fall on different dates? This frequently asked question can also be addressed in the reverse: Why do the equinoxes not always occur on the same days each year, that is the same dates? Consider how the Earth orbits the Sun, not in 365 days, but an additional quarter of a day. Hence, the reason for adding a so-called leap year every four years. In other words, factoring in another day to the calendar, so that there’s not a gradual drift of date through the seasons; also, for the same reason the precise time of the equinoxes are not the same each year. For the most part, this adjustment will occur about six hours later each year, but only with a jump of a day (backward) in leap years.

From a technical perspective, predicting the equinoxes comes down to the scientific perspective that entails another kind of equator. In this case, the celestial equator, which defines a great circle on the imaginary celestial sphere in the same plane as the Earth’s equator. Naturally, the celestial sphere is itself an imaginary sphere of an arbitrarily large radius, which is concentric with our planet rotating upon the same axis. Thus, all objects in the sky can be thought of as projected upon this imaginary sphere that provides a practical celestial tool for so-called positional astronomy. In other words, superimposing a great circle on the imaginary celestial sphere defining a projection of the terrestrial equator out into space. As a result of the Earth’s axial tilt, the celestial equator is inclined by ~23.5° to the ecliptic plane, which translates to 0 declination. As previously mentioned, but here expressed in a capsule summary relevant to what was just mentioned, declination is one of the two coordinates of the equatorial coordinate system while the other is either right ascension or hour angle. Moreover, declination in astronomy is comparable to geographic latitude but projected onto the celestial sphere. These points of intersection are called equinoctial points, the vernal point, and the autumnal point. By extension, the universal term “equinox” may also denote an equinoctial point.

A Reliable Primal Calendar: Considering what we know (and in some cases, infer) about Ancestral Puebloan cosmology, much can be learned from their practices. Our Gregorian calendar has benefited from the foundation it created and was based upon previous foundations of similar thought. Regrettably, the invention of the clock rules our technological society today. It, therefore, follows how the gulf between awareness of the lunar and solar cycles is leading Western man to lose (read, “not grasping”) the entire notion of natural cyclical time and its important relationship with space. While the solar year has a strong influence on plants and animals, this force does not fully (or adequately) explain the scope of their behavior. Nor does it aid in the effort of our self-discovery. Understanding how the physics of space and time intertwine with biology. Specifically, the nuances of biological time, including our lives, has been utterly displaced for countless centuries. Archeoastronomy, which manifestly entails comprehension of solstices and equinoxes, is an intellectual windfall. Hence, a pragmatic means how we can look back in time at ancient cultures that practiced its science, and thereby increased their knowledge that advanced societies in many ways. Being in touch with the heavens also gave them the power of prognosis to some degree. At Chaco Canyon, for example, the alignment of the structures, both solar and lunar, had something to do with their well-ordered minds, as well as the sole reason the Chacoans built this great compound where they did.

That said, the question for people today can be stated: How much importance is placed on the stars other than those who believe in astrology? Singling out one of those bright lights in the dark sky, one might also ask how important is the sun––chiefly, our yellow dwarf star? We know that its nuclear fusion makes life on earth possible. Moreover, its relative size, distance from our planet, intensity, stability, gravity, as well as Earth’s orbit and the rotational axis of its sphere combines to create ideal conditions for life. It’s also likely in the universe only an infinitesimally small fraction solar systems numbering in the billions or trillions have similar planets that aren’t hostile environments. We just need to put the importance of the sun into proper perspective.

To use an illustration, and starting at the bottom of the food chain, plants grow by a process of photosynthesis. Tiny insects and other invertebrates feed on these plants, as well as decaying matter. Everything on the planet, therefore, eats everything, that is ultimately this is the case. Birds, amphibians, and fish feed on these small animals, and so the same process extends further up the food chain. Animals also tend to give birth during seasons when food is most plentiful, for the survival of their offspring and their recovery. Understanding the timing of specific temperatures (i.e., seasons) over the course of a solar calendar is another way of demonstrating how determining the correct time to plant crops, predict the rising of rivers, and comprehend migration patterns of fish and wildlife, represent tangible benefits of archeoastronomy, as well as biological time. Prediction based on this science was, therefore, crucial to ancient minds that patiently observed the clockworks of the cosmos. 

The Winter Solstice Exacting Predictions: Depending on the shift of the calendar, this eventful time of the year and its seasonal change in the northern hemisphere occurs on December 21 or 22 and June 20 or 21. Conversely, it follows how the summer solstice in the southern hemisphere occurs on June 21 or 21 and December 21 or 22. At these dates, from one day to the next the sun changes minimally in declination. Indeed, it appears to remain in one place north or south of the celestial equator (i.e., a seeming standstill). To predict a solstice the way the Ancestral Puebloans did, it required keen and precise observations over time. However, considering the more technical aspects of such prediction, it’s remarkable these people were able to do what they did using primitive means.

Naturally, such prediction begs the question: Why was there such interest in knowing when the longest day of the year arrived, which defines the summer solstice, and the converse, shortest day, the winter solstice? Apart from the obvious, meaning the days are longer during the summer solstice, the temperature is warmer, and then continues to get hotter over the next few months. The sun is also higher in the sky. Consequently, the sun’s rays are more vertical, thereby providing more direct sunlight and less atmospheric cooling. It also follows the opposite is true around the winter solstice. 

Today, we can only assume the science of such prediction for the Ancestral Puebloans (indeed, for all Archaic Era and prehistoric cosmos-minding peoples) was manifest in the two extremes of each solstice. We can also assume the solstice, like the equinoxes, or even lunar predictions, held special importance for practical societal benefits (i.e., when to hunt or plant or find game or gather edible plants, and so on). Again, to mention the significance of biological time, for those cultural and global societies that depended on fish for part (or all) of their sustenance, knowing when the fish were on the move, or else laying still in the water was equally noteworthy. For the Ancestral Puebloans, however, this was not the case. Nevertheless, other factors relating to hunting, lighting, and when game was on the move was crucial information, and not just having an awareness of such events. Everything else relating to the change of seasons was also important in the sense of social praxis. Moreover, we learn from the Puebloans how there was religious relevance to these changing seasons, thereby entwining the practical with the religious.

Predicting the equinoxes also entails two other important factors for the Ancestral Puebloans. At both times, the stated amounts to the sun’s position during the day and night are equal in length in all parts of the planet. For instance, the vernal equinox marks the beginning of spring in the northern hemisphere. Hence, the days succeeding this seasonal change. Therefore, lengthening the amount of daylight time a little more each day until the longest day of the summer solstice. From that point, the days begin to shorten. However, the days are longer than the nights until the autumnal equinox, after which nights become longer than the days. These passing days also continue losing daylight until the shortest day of the year at the winter solstice. 

For modern people having all the comforts of home, and at any time of the year (i.e., electricity and heat or air-conditioning), the comfort levels of Ancestral Puebloans were predicated on the light and heat of the day, that is for productivity; otherwise, cold and darkness could only be endured for months on end. 

Other Predictive Capabilities: Without having the technical ability to gauge either the solar equinoxes or solstices, these ancient sky watchers may have charted the positions of the stars to keep their place in time. Hence, a pragmatic-based cosmology practiced by Mesopotamians, Babylonians, and Greeks among other civilizations. In this light, stars expressed a utility beyond their scintillating effect upon the senses. These celestial bodies also appear to move in regular routines at predictable times of the year. One can assume the Ancestral Puebloans took note of this, as well. The same notion applies to planets. Still, star gazing was intense, for, in any given quadrant, there are more than one thousand stars visible to the naked eye. Although some among the many are brighter than others, the overall count is something on the order of some five thousand stars relative to our solar system’s local neighborhood as viewed from the Earth. Stars that are clustered and grouped in formations also tend to be more noticeable.

Here, again, we can make an assumption, in that these ancient stargazers, with their math oriented minds, must have noticed such aspects relating to the routine of the heavens they observed. Such knowledge also relates to the broader subject of archaeoastronomy and is plainly tied into a prediction of the solstice and equinox events. As a consequence of what the Ancestral Puebloans had accomplished given their cosmology, fables handed down to their successors entail elaborate stories. Some of them are cosmological, and some are terrestrial. As such, there is also a religious or ceremonial aspect to what some of the stories import.

That said, in contemporary times, empirical evidence supports the hypothesis that Ancestral Puebloan religious motifs have undergone changes over the centuries. Hence, preserved in Puebloan traditions and intended to preserve their past. For example, the role of the kachinas in Hopi society. Kachinas (also spelled katchina, katcina or katsina) are spirit beings or personifications of objects (or things) in the real world. The central theme of kachinas may, therefore, be construed as a presence of life in all objects that makeup the whole of the universe. This notion is based on the concept everything has inherent life force energy, and, therefore, humans must learn to interact with kachinas or cease to survive. For the Hopi People, kachinas subsume a noteworthy religious (or spiritual) significance in their religious ceremonies, and possibly well beyond; at least, a very different significance compared to all Puebloans. For instance, the Hopi Kachina Cult is noted from the early part of the 14th-century, say, around 1325. However, some researchers, among other academic researchers, question whether this cult was intrinsic given its association with indigenous religion. Fundamentally, their query comes down to the finer point whether the cult practice was imported directly (or indirectly) from the Aztecs. Perhaps the practice was imported from the Mayans, say, sometime during the prolonged Great Drought that happened around 1287. There are still others who contend the cult originated from present-day Mexico. 

Whatever the origins of this enigmatic cult, it is profound and deeply embedded in Hopi ideology and religion. As for the role kachinas serve in any Puebloan society, these spirit beings act as moral models to the people, each engendering a motif of living in a correct way. There are hundreds of kachina icons relegated to the level of supernatural spirits, all of whom represent a positive natural and spiritual influence on the Hopi. As an example, knowing whether the people are blessed with rain and a good crop yield fall under the heading of a positive natural and spiritual influence for the tribe. Moreover, the elders of the tribe are given access to greater powers by the kachinas to help bless the entire world and keep it in balance. Outsiders, however, should they have access to the same powers, would lead to something the Hopi refer to as a “life out of balance,” ultimately ending in the destruction of this, the so-called Fourth World. The word they use for this might also be construed as a Hopi onomatopoeia––Koyaanisqatsi––somewhat difficult to pronounce, though, nevertheless, a designation with its fearful consequences.

Additional Background: Because kachinas can represent anything in the natural world, even in the cosmos (i.e., from a revered or loathsome ancestor to an atomic element), the local pantheon of these spirit beings for the Puebloans (which number around four hundred) varies in each community. For instance, there may be kachinas for the sun, stars, clouds, rain, thunderstorms, crops, insects, and on and on the list goes. Mostly, kachinas are better understood as having humanlike relationships. In this light, they may have different members of a family unit––mothers, fathers, brothers, sisters, grandfathers, and so on. Although kachinas are never worshiped (hence, a pivotal statement about spirit beings). Still, they are viewed as potent beings. If one gives veneration and respect to a kachina, then he or she can use the power for goodness. For example, healing the sick, fertility, protection, even bringing rain to drought-stricken places. One other note about kachinas, as they apply to Hopi beliefs, is how they are said to live on the San Francisco Peaks rising above Flagstaff. The most important among kachinas is named “wuya,” and dozens of other names under this epithet.

Nature’s Tracking Time And The Role Of Archaeoastronomy: To the Puebloans, as well as the Ancestral Puebloans, it should be apparent to the reader how nature plays an integral role in their traditions, as does cosmology. From the Hopi’s “Prayer from the Summer Solstice Celebration,” we glean something about how they think and pray, which represents, in part, similar insight held by all Puebloans. This significant prayer, in part, is as follows:

Nature’s means of tracking ‘time’ is in cycles. Consider noting the full moon, the new moon, the solstices, and the equinoxes on your calendar and feel these as ‘clocks’ as well––each one containing energies to serve the earth’s transition points in the year. 

Spring Equinox is New Year’s Day! With other’s, bring your ‘resolutions’ and what you wish to ‘seed’ beside the seeding already occurring in the earth.

Summer Solstice is LIGHT! Renew, release, enhance. Celebration! Counting visible blessings. What is ready to release into the light? What in the physical world of yourself and earth do you wish to enhance? 

Autumn Equinox––Harvesting; beginning of an inward pull; readying for new cycles (like seeds); an opportunity to feel imbalances and rebalance with self, other, and earth.

Winter Solstice––Stillness. Darkness. Purification. Time to surrender to the shadow and invite purification in warmth of fire, friends, and faith. It represents the death aspect of rebirth––without it, rebirth cannot happen. What can you see more clearly in the dark of night?

Transition points in the month (from this same prayer):
New Moon––it’s like a mini-spring equinox and winter solstice. Energies are more inward and offer the opportunity to both reflect and seed? What do you want to grow into its fullness?

Full Moon––it’s like summer solstice and fall equinox. Energies are external. Gratitude. Fertility, harvest, celebration, as well as readying to reseed as in fall.

Notice that in all the equinoxes, solstices, and the full and new moons there are both death-ing and birthing energies present––death-ing means the origin of creation. One without the other means growth cannot occur. How are these energies in balance and at one in you at each phase of the cycle?

Conclusion (Of A Sort): Archaeological evidence illustrates how humans viewed the cosmos (i.e., their differences and similarities) seeking answers to some of their questions or else address specific concerns. These celestial observers followed noted cycles of lighted points in the sky: the sun, moon, stars, and some of the more visible planets. Such heavenly bodies signified power, perhaps even afforded some comfort, in helping people prognosticate events. For example, after a seventy-day absence from the night sky during the summer solstice, the appearance of Sirius is associated with annual spring flooding. Known as the “Dog Star” (reflecting its prominence in the constellation, Canis Major), Egyptians based their calendar on its heliacal rising the day it becomes visible. This anticipated event is just before sunrise after moving far enough away from the glare of the sun. However, this notable celestial observation for the Egyptians is not viewed in the same way by other cultures. For instance, ancient Greeks held that Sirius’ appearance heralded a hot and dry summer change of weather. So, instead of forecasting flooding, its beacon of light signaled debilitating effects on plants and humans (i.e., wilting of plants and men weaken while women become aroused). Here in America, we traditionally consider Sirius as a stellar icon representing the famed dog days of summer, which is neither favorable nor unfavorable. It’s merely a customary attitude.

From this one example, it’s evident how select planets or stars have governed the seasons for different civilizations throughout recorded history, and, of course, for prehistoric cultures without a written history. Celestial bodies have always affected social attitudes, sometimes good and sometimes bad. Closer to our planetary home, the Earth’s companion moon affects the oceans and creates the ebb and flow of tides. Those ancient civilizations that observed the night sky on a year-round basis learned what to look for, each finding something pertinent to their culture and religious mindset. But it wasn’t just the four acclaimed events (the solstices and equinoxes) throughout the year that got their attention. The sun and moon held sway over these people for other reasons, for these were the primary and localized governing bodies that made their cosmology work. In short, the life process for prehistoric people was directly tied to the cosmos. Remarkably, lunar calendars were as predictive as solar light. For some cultures, the dark and light periods of the moon had everything to do with the wellbeing of these ancient societies or else the exact opposite. It follows how studying the stars (and planets) was a complex and localized cosmology that first had to be worked out over time. The changing lunar light was also carefully noted, as though the people read a yes or a no regarding hunting and fishing, even plotting their next migrations to time their arrival with other life forms these people depended on for game. Thus, the element of biological timing.

This testimony brings to mind one of the world’s most famous archaeological ruins and its relationship to astronomy, particularly archaeoastronomy––Chaco Canyon. Mentioned at the outset of this volume were this compound’s ultra-special layout and design in some of Great Houses, even lesser dwellings. Not only are some of these domiciles solar-aligned, but also lunar-aligned. Suffice it to say how this Southwest archaeoastronomy site is the only place where dwellings are aligned to both solar and lunar light, and possibly the only site of its kind on the planet.

(end Volume VI)