Episode 29: The Astronomy of Saharan and Sub-Saharan Africa

May 10, 2023

The oldest plausible astronomical artifacts known are African, as are many of the oldest megaliths, around 10,000 of which dot the Sahara and whose orientations are astronomical in character. We then briefly survey some of the creation stories and sky myths from a number of the peoples of sub-Saharan Africa. Finally, we turn to a few of the more unique calendars in the region.


Good evening, and welcome to the Song of Urania, a podcast about the history of astronomy from antiquity to the present with new episodes every full moon, or thereabouts. My name is Joe Antognini.

Well last episode we started our grand tour of the astronomy of the globe with the astronomy of prehistoric Europe. In this episode we’ll now travel south of the Mediterranean and take a look at the astronomy of Africa. If I were starting this podcast all over again I’d probably begin here rather starting with the astronomy of ancient Mesopotamia. After all, humanity originated in Africa so unsurprisingly the oldest astronomy is African. But as we saw last episode in the astronomy of prehistoric Europe, the longer back in time we look, the more speculative our knowledge becomes. So we will begin with some of the oldest and most tentative connections to astronomy and then see how various modern groups practice astronomy, at least around the time of colonization when more definitive records start to survive.

But before we get into the astronomy proper, it would be worth spending a little bit of time getting familiar with the geography and population history of Africa. Africa sits rather symmetrically about the equator and so its climate going north to south exhibits a certain symmetry about the equator. Going from north to south, the northernmost strip of Africa is really quite distinct from the rest of the continent. I titled this episode the astronomy of Saharan and Sub-Saharan Africa because culturally North Africa bears more of a connection to other Mediterranean cultures along with the cultures of Arabia. South of this strip is the vast Sahara desert, which is a bit of a redundant name since Sahara simply means “desert” in Arabic. Technically the Sahara is only the world’s third largest desert, but that is only because Antarctica and the Arctic both count as deserts. But of the hot deserts the Sahara is by far the largest, being more than three times larger than the next largest desert in Australia. The Sahara is probably the most important geographical feature of Africa, at least in terms of the histories of the people who have lived on the continent, because it severely limited the extent of cross-cultural connections between Africa and the rest of the Eurasian landmass. The Sahara sits at around 30 degrees of latitude which is where the Hadley convection cells in the atmosphere at tropical latitudes meet with the Ferrel cells at the temperate latitudes. Where they meet are the so-called “horse latitudes,” and there is little large scale atmospheric activity there. Consequently these latitudes tend to be characterized by low wind and low precipitation. Now, the Sahara is not totally inhospitable. Since ancient times there has been a network of trade routes that have criss-crossed the desert. But to make the trek worth it, only very high value goods would be moved across the desert, and historically the major ones were gold, salt, and slaves.

Just south of the Sahara is a band of temperate climates called the Sahel, and here agriculture is possible. Unlike the Mediterranean climate to the north, the Sahel sees its big rains during the summer rather than the winter, so crops that do well in the Mediterranean tend to fare poorly in the Sahel and vice versa. Moving further south is a band centering on the equator where the climate is, unsurprisingly tropical and is characterized by dense rainforests. Then moving further south still there is a similar pattern of climates but roughly in reverse. South of the rainforests the climate becomes more temperate with the famous African savannas. At around 30 degrees latitude south of the equator you hit the horse latitudes again and there is another large desert, the Kalahari desert, Kalahari deriving from the Tswana word for “great thirst.” And the southernmost strip of the continent once again has a Mediterranean climate.

Apart from this north-south variation in climate, geologically there is a substantial east-west variation, sweeping from around Namibia in the southwest, and then north and to the east up through Ethiopia. The northwestern half of the continent is geologically older, relatively flat and low-lying. The eastern half is younger, more geologically active and generally at higher elevations. On the eastern side of the continent is where the African plate meets another tectonic plate, the Somali plate. These two plates are separating from each other, the African plate drifting west and the Somali plate east. The long boundary between the two forms the so called Great Rift Valley, and along this strip running north to south on the eastern side of the continent there is a string of large lakes, called, uncreatively, the Great Lakes.

This geography played an important role in determining how Africa has the population distribution that it does today. Now Africa is very large and very diverse, there are more than a billion people who live there and some 2000 languages. But the populations of Africa can be grouped into five very broad families, largely based on their language families, but also from genetic and cultural markers as well. The first of these are those who speak languages from the Afroasiatic family. This population is distributed throughout North Africa, the Sahara and to some extent the Sahel, and northeastern Africa. For those of us with a Western background, the best known branch of the Afroasiatic languages would probably be the Semitic languages, Hebrew, Aramaic, Akkadian, and so on. But around half of the Semitic languages are African and in fact the Semitic languages are actually the only branch of the Afroasiatic family that extended out of Africa.

The second major family is the Niger-Congo language family. This family developed in West Africa and saw a rather remarkable expansion. Around 4000 BC or so agriculture was independently developed in West Africa by people who spoke Niger-Congo languages. This may have been by peoples who spoke languages from the Bantu branch in particular, or perhaps their neighbors. But either way, not too long after, thanks to this new technology speakers of the Bantu branch of the Niger-Congo family then were able to rapidly expand from around modern day Cameroon to almost the entire continent, to the Indian ocean in the east and all the way down south to the Cape of Good Hope. Today almost everybody south of the equator in Africa are descendants from this Bantu expansion.

In this process of expansion, the Bantu peoples encountered and largely overwhelmed two other groups, who were hunter-gatherers. At the equatorial latitudes there’s the Pygmies. These groups were heavily fragmented by the Bantu expansion and unfortunately their indigenous languages mostly died out, apart from loanwords which persisted into the Bantu languages that they now speak. The other group is indigenous to the southern latitudes. Anthropologists broadly call this group the Khoisan because the group consists of two main parts, the Khoikhoi, who are pastoralists, and the San, who are hunter-gatherers.

Now a word about nomenclature. The words for these two groups, the Pygmies and the Khoisan are not great. In the case of the Pygmies they generally consider the term to be pejorative, and in the case of the San, the word derives from a Khoikhoi term which is pejorative in that language. But these groups have only native words for their individual ethnic groups like the Mbuti and Twa among the Pygmies or the Kung and Ju’hoansi among the San. Because they have no word that refers to the collection of these groups there hasn’t been any obvious alternatives, so the terms have persisted in the literature. At any rate I will follow the lead of the anthropologists here and refer to them by the standard terms Pygmy and Khoisan.

As an aside, the Khoisan is a particularly fascinating group linguistically. The Khoisan languages are unique for including a wide variety of clicks as phonemes. And in some cases some members even speak a second language consisting entirely of clicks which are used for hunting since those sounds are less likely to alert their prey to their presence. Khoisan languages influenced some of the Bantu languages in southern Africa like Xhosa, which adopted some of the click phonemes in Khoisan languages.

The Khoisan and Pygmies are also particularly notable for their genetic diversity. Roughly speaking, if you were to look solely at people’s genomes, you would divide the human population into three broad categories: one group with extremely high genetic diversity, another group with moderate genetic diversity, and a third group with relatively little genetic diversity. Of these three groups the third is by far the largest. Everybody whose recent ancestors originated outside of Africa, some 7 billion people, have relatively low genetic diversity. The second group, those of moderate genetic diversity, consists of the vast majority of the roughly one billion people whose recent ancestors originated in Africa. The last group, those with high genetic diversity, number only about a million and consist of members of the Pygmy and Khoisan. The scale of this difference is really rather astonishing. If you were to take two people at random from the low diversity group halfway around the world from each other, say a Norwegian and a Navajo or an Indonesian and a Spaniard, and you compared the similarity of their DNA, and then you did the same for two Khoisan people living 100 miles apart, you would find that the DNA between the two Khoisan people has 20% more differences than the DNA between the Norwegian and the Navajo or the Indonesian and the Spaniard. Most of the human population descended from a group that underwent two major population bottlenecks, one of which seems to have been particularly severe. During this bottleneck, the population that expanded out of Africa seems to have been reduced at one point to a few tens of thousands of individuals, or possibly even as few as a few thousand. Another, less severe, bottleneck seems to have occurred somewhat earlier when humanity was still in Africa and accounts for the reduced genetic diversity of most of the African population. What exactly these events were has been the subject of some speculation. A leading theory of some time was that most of humanity died off in the aftermath of an eruption of a supervolcano in Indonesia 75,000 years ago, though more recent evidence has cast doubt on this hypothesis. But at any rate both these events occurred after the Pygmies and Khoisan split from the rest of humanity likely more than 100,000 years ago, so these groups have retained a much higher genetic diversity.

Well, I told you that there are five language families in Africa, and we’ve now seen the Afroasiatic, Niger-Congo, Pygmy, and Khoisan. But there is one more which we will not look at until a later episode. This is the Indonesian language family which is present in Madagascar. Perhaps surprisingly, the people of Madagascar are a mix of native Africans and Indonesians who 1500 years ago migrated some 5000 miles west. As Jared Diamond put it, it’s as surprising as if Christopher Columbus had crossed the ocean blue and when he got to the Bahamas, he had discovered that Swedes had been living there for a millennium. As such, culturally the astronomy of Madagascar belongs more properly with the astronomy of Oceania which I’ll cover in a later episode.

Okay, so with that survey of the geography and people of Africa we can now dive into the astronomy proper a little bit more. As I mentioned at the outset, the history of the oldest astronomy is necessarily a history of African astronomy, so it should be no surprise that the oldest artifact which is plausibly astronomical in character is African. This is a bone found in modern day Eswatini called the Lebombo bone. The Lebombo bone dates back around 43 to 44 thousand years ago and is what is called a tally stick. Tally sticks are some of the oldest human artifacts around and are bones with a series of notches in them that appear to have been used, as the name implies, as an aid for counting. Tally sticks have fairly regular notches grooved into them, suggesting that they were made deliberately, rather than just random notches that might have come about when someone was carving up some meat. The Lebombo bone is the oldest definite tally stick and it has 29 notches grooved into it. A careful analysis of these notches suggests that the notches were made with different tools, which in turn implies that they were probably made at different times rather than all at once. As I mentioned in the last episode, anytime you see an artifact with the number 29 it’s maybe not definitive evidence that the artifact is astronomical in nature, but it is certainly wriggling its eyebrows suggestively since this is roughly the number of days from new moon to new moon.

There is a younger, perhaps more sophisticated artifact, called the Ishango bone, that was discovered in the modern day Democratic Republic of Congo. This tally stick is about 20,000 years old and has three columns of tally marks, one with 48 tallies, and the other two with 60 tallies apiece. The columns then seem to be grouped into a series of smaller subdivisions, but what the meaning of these divisions is is not obvious. Some scholars have pointed to the number 60 that appears twice as being evidence of an astronomical connection since this is roughly the number of days in two lunar months, but at least to me the connection seems forced. Others have pointed to the groupings of the tallies in the third row, which are 19, 17, 13, and 11, which are all the prime numbers between 10 and 20. But this seems to be the sort of artifact that a sufficiently motivated scholar can massage whatever explanation they want to fit the data. Almost certainly the original purpose of this artifact has been lost to time.

Well the next oldest examples of interest in the heavens in Africa comes from the rock art of the Khoisan, the oldest examples of which dates back around 26,000 years, long enough ago that Polaris was once again the north star. These paintings generally depict groups of people, usually drawn in a highly elongated way, along with animals. But among some of these paintings there are celestial bodies, particularly the Sun and Moon. And some even appear to depict comets or meteors, drawn with a dot surrounded by a halo and possessing a long tail. Though as always with the oldest artifacts, there are always alternative interpretations. In this case it’s also been suggested that the comet-like shapes that appear in some of these paintings is in fact a depiction of a trance state.

Moving to a somewhat more recent set of artifacts, the Sahara has a number of megaliths that have an astronomical connection similar to the megaliths of Europe. Now I titled this episode the astronomy of both Saharan and Sub-Saharan Africa because the Sahara wasn’t always the desolate deserted Sahara we know today. Due to oscillations in the Earth’s orbit, the Sahara, or at least the region that the Sahara occupies today, alternates between a desert state and a wetter state that can support grassland. Around the end of the last ice age, the Sahara began to transition to this wetter state, which peaked in moisture at around 6000 BC. After this point the region gradually became drier, and by 2500 BC was closer to its present state. But even towards the end of this period, the region seems to have been able to support human life and most of the megaliths date from between 3000 to 2000 BC. Many of these megaliths are accompanied by skeletons and so are presumably funerary in nature, which would make them similar to the megaliths in Europe. The vast majority of these megaliths are in the western end of the desert, with another cluster in modern day Chad, though some kinds of monuments are distributed across the entire region.

There are around 10,000 megaliths in the Sahara, and scholars of these megaliths have grouped them into 40 broad classes, which is quite a lot so I won’t detail them all exhaustively. But to list a few of the more common kinds, one is a mound of earth or stone called a tumulus with a line of stones at one end. Another is a mound of earth or stone in a crescent shape, and similarly there are tumuli in a V shape consisting of two relatively straight arms of stone. One of the more complex kinds of megaliths are what are called keyhole monuments where there is a tumulus surrounded by two concentric rings which are then connected to each other by a passageway.

As with European megaliths, the orientation of Saharan megaliths is not random. The builders of the Saharan megaliths had a strong preference to orient their structures to the east just like their European counterparts. But different kinds of monuments have different distributions in orientation. Some of these, like crescent monuments, were very deliberately built oriented towards the east since there is an extremely narrow distribution of orientations. The rare exceptions that were built facing west generally have female skeletons present unlike the vast majority of monuments with male skeletons, which suggests that the builders oriented the tombs of men towards the east and the tombs of women towards the west, at least in some cultures. There is also substantial regional variation in the ratio of male skeletons to female skeletons present in these monuments. In the central parts of the Sahara male skeletons are predominant, but female skeletons are still frequent, around 22% of the total. But in the western ranges of the Sahara the distribution shifts to almost exclusively male with women making up only 0.6% of the skeletons found buried at these crescent monuments. Other kinds of monuments, like the tumulus with a line of stones, seem to have built without too much thought to their orientation since they have a very broad distribution of orientations with a slight bias towards south if anything. But most types of megaliths in the Sahara do seem to have been built with a particular orientation in mind. One of the interesting features of the range of the distribution of orientations is that while they fall towards the east with some scatter, it is rare that any structures are oriented beyond the position of sunrise on the summer or winter solstices, and even rarer that they exceed the position of the lunar standstills.

Megaliths are also present south of the Sahara, though less is known about these monuments. It is probably the case that the desertification of the Sahara led to Saharan monuments being better preserved than Sub-Saharan monuments, and probably more importantly, easier to discover since there is no vegetation to obscure their presence. And in fact because there are basically no trees in the Sahara, many of the Saharan monuments have been studied using satellite imagery from Google Earth.

Interestingly the preference for burial sites to face east extends even further south to the Khoisan peoples in southern Africa. Anthropologists who have studied their burial practices have found that, although there’s some diversity in funerary practices among the different nations, the general preference is to bury the dead facing the east and almost all of the other cultures who don’t, bury their dead the other way, facing west. When asked by anthropologists why they oriented the dead in the way they did, some groups like the Gwa said that the direction that the face was looking would be the direction that the ghost of the deceased would start walking. By orienting it towards the setting Sun, the ghost could join the other ancestors who had also walked in that direction. Among the Basotho the deceased was buried in a crouching position facing east because the god Modimo was associated with the rising sun, and by facing that direction they would be ready to spring to action at once when the call of Modimo came. But other groups, such as the Naron, simply said that it was their custom to orient the dead towards the east but did not know of any rationale as to why. In the rare examples of where the dead are not oriented east-west, the exception seems to prove the rule. Among some of the northernmost Kung the dead are buried north-south, but care is taken that the deceased is put on their left side so that their face is still pointed east. And incidentally, among the Tswana and Sotho the association of the east with the dead is so strong that people avoid sleeping with their head towards the east.

Well, this is perhaps a nice transition from the astronomy of ancient African civilizations to more recent practices. Without written records there is not too much more we can say about ancient African civilizations, so we’ll skip ahead now to the astronomy practiced in Africa from the late 19th century onwards when the first European colonizers and later anthropologists began to keep records on African cultural practices. Now I’m actually skipping over quite a bit of interesting astronomy that takes place in the Sahel during the late middle ages, particularly in Timbuktu, but this astronomy was more associated with the arrival of Islam in the region so I’ll save it for a future episode when we go into the astronomy of the Islamic Golden Age.

Now as with all civilizations, the civilizations of Africa have identified constellations in the sky. But given that there are some 2000 distinct ethnic groups in Africa I can only give a small sampling of the ways that they read the stars. But there are a couple of features that are unique to the African sky relative to the European sky, particularly for peoples at equatorial latitudes or further south. There, certain features that are very prominent in the northern hemisphere like the Big Dipper, are either less prominent because they are low on the horizon or are not visible at all. Instead the more striking stars and asterisms of the southern hemisphere play a more prominent role. In particular the stars of Crux, the southern cross, and Centauri, the Centaur are among the more important features of the sky, along with the Large and Small Magellanic clouds, which aren’t visible at all north of the Tropic of Cancer.

Among the peoples who speak Setswana, a Bantu language in southern Africa, the Large Magellanic Cloud is called Tlala, which means “famine” and the Small Magellanic Cloud is called Kgora, which means “plenty.” In this region if there have been poor rains, the atmosphere will be dustier and the Small Magellanic Cloud will be obscured. Then the harvests will be poor and only the Large Magellanic Cloud, famine, will be observed. But if the rains are good the atmosphere will be less dusty and the Small Magellanic Cloud, plenty, will be visible.

Another feature of the sky at equatorial and more southern latitudes is that the center of the Milky Way appears much higher on the sky, passing overhead at around 29 degrees of latitude south. Around the equator, the Milky Way appears to sort of swirl about the sky, pivoting between two points. Consequently, the Tabwa or Lungu people who live in the eastern reaches of the Democratic Republic of Congo, called the Milky Way “kipinda busiku,” which means “bow of the night,” with the word “kipinda” having an association with bending in tension like the string of a hunting bow or a ladle swirling around a pot of millet beer. Since the Milky Way is always prominent in the sky it is used as a timekeeping mechanism during the night, unlike northern cultures who generally use the circumpolar stars like the Big Dipper or Cassiopeia.

Another prominent feature of the African sky is the constellation Orion and the nearby Pleiades. Since this group of stars roughly falls along the celestial equator it is easily seen by peoples at all latitudes. The association of Orion with hunting seems to be fairly common, not unique to the western canon. The Tswana saw the three stars of Orion’s sword representing three dogs chasing three pigs, represented by the three stars of Orion’s belt. The Khoisan also read Orion as a hunting scene. The hunter is the star Archenar, which is some distance away in the constellation Eridanus. The three stars that form Orion’s belt represent three zebras that the hunter is trying to kill. He has fired an arrow represented by Orion’s sword, but the arrow has missed the zebras. Beyond the zebras is the star Betelgeuse, which is a lion and off to the side the Pleiades represent the hunter’s six wives. In the Khoisan’s view, the hunter is perhaps not a shining role model to look up to even he is literally shining and you are literally looking up to him. Having missed the zebras, the hunter is too afraid to retrieve his arrow due to the lion. But he is also too embarrassed to return to his wives without any food, so he spends his days skulking off in the distance.

More generally, among the Khoisan, the stars are seen as being animals or people from earlier times, similar to the view promoted by Marcus Manilius that I talked about in Episode 27 that the Milky Way was composed of the souls of honorable men, most of which in his view happened to be Romans. Similar beliefs among the Xhosa led to a taboo against pointing at the sky. In the Xhosa culture it is disrespectful to point at an elder, and this extends to deceased elders, so people do not point at a grave, nor do they point to the sky. Instead if they do need to point a star out, they will bend their finger and point with their knuckle.

The stars around Orion also seem to mirror social life among the Xhosa as they do among the Khoisan. During the evenings around harvest time, Sirius and Canopus, the two brightest stars in the night sky are visible low on the western horizon right next to each other, and the Xhosa gave them the names “the suitor on the left” and “the suitor on the right.” The arrangement of stars was interpreted as a household. The Xhosa are polygynous, so a man would have multiple wives, but among them, two held special significance. The first is the man’s first wife, who is also called the “inkosikazi,” or principal wife. The second is the “umfazi wasekunene,” or the “right-hand wife.” The rest of the man’s wives, called “qadi,” would be subordinate to one of these two wives who would jointly manage the household. The stars Sirius and Canopus were taken to represent these two wives of the household, and the surrounding stars the other wives in the household.

As to the origin of the stars there is a wide diversity of explanations. Among the Zulu of southeastern Africa the word for star is “inkanyezi” which is also the word for firefly. In one tale the night sky is dark because the heavens have accumulated the smoke from all the fires that have ever been lit and some of the sparks from these fires persist in the sky as the stars. Another tale from the San has it that when the Sun goes to bed in the west at night, he pulls a blanket over himself to keep warm, but the blanket is old and has holes in it, producing the stars.

Well, in addition to these stories, there are a wide variety of more general creation stories across Africa. Again, with some 2000 ethnicities I can only briefly sample a few of them, and as with the Greek myths I talked about way back in Episode 7, there are no canonical versions of these stories. Different people will tell them their own way so many of these stories have a number of variants. Oftentimes the stories that get recorded by anthropologists have been a number of distinct stories that they have heard that have all sort of been smooshed together.

One version of the Zulu creation myth goes like this: One day the god iNkosi, which simply means Chief, saw that a young man was making trouble. This time the young man was riding iNkosi’s favorite white horse, but this was far from the first time that this young man had been making mischief. INkosi decided that enough was enough and resolved to send the man down to Earth so that he would cause no more problems in the heavens. INkosi ordered that a hole be cut in the sky and that an intestine be tied around the waist of the young man. INkosi then lowered him down to the Earth. When the man set foot on Earth, the man saw that he still had an umbilical cord attached to him, so he found a reed and cut the cord off. A month passed and iNkosi decided to check to see how the man was doing, so he opened the hole back up and looked down. To his dismay, the man was sitting under a banana tree looking very thin and weak. INkosi asked himself, “What is wrong with my son? Was there no food and water for him on Earth?” INkosi then realized that the man was very young and was all alone. So he decided that he would give the man a companion and called upon the most beautiful woman in the heavens and said to her, “Today you must leave the heavens and go down to the Earth to live with your man so that he might have somebody with him who will make him happy.” INkosi then tied the intestine around the woman’s waist and lowered her to the Earth through the hole in the sky. When the woman touched the Earth, the man woke up and was astonished with what he saw. He said, “I have never seen anything so beautiful since I came to this place. This woman must have been a gift from my father, for who else can give such beautiful gifts?” Then he took a reed and cut the umbilical cord of the woman, too. After this, iNkosi pulled the cord up to heaven and sealed the hole shut so that the people on Earth could not look up into the heavens, and the gods in the heavens could not look down upon the Earth and see the manner in which the people multiplied. This is why the Zulu call themselves the Zulu, because in that language the word “Zulu” means “heavens” or “sky,” and this is where they came from.

One thing to note about African creation stories in general of which this one is an example, is that they are focused mostly on the creation of the human race rather than the creation of the universe itself. Being polytheistic, most of the peoples, particularly in southern Africa had a rather deistic conception of the creation of the universe. Many have a conception that there was some great god who created the universe at one point in the past, but once his work had been completed he more or less left the universe to its own devices. Given his apathy towards humanity, generally the peoples of southern Africa had only a vague interest in him in return. Their religious practices centered far more heavily around other deities that took a more active interest in the lives of humans. This kind of thing is by no means unique to Africa. We see it as a prominent feature of Greek mythology, too. The Greeks had their own vague creation myth, but the Greeks almost never interacted with the primordial gods. The gods that the Greeks interacted with on a day-to-day basis were several generations removed from the original gods and had associations with things that were more practically relevant like the goddess Diana to hunting or Aphrodite to love.

An exception to this comes from the people known variously as the Bushongo or Songora, who are a Bantu people of central Africa. They have a creation story that addresses the creation of the universe itself. One version of it, recounted by Jarita Holbrook goes like this:

In the beginning it was dark and there was nothing but water. The god Bumba was alone. One day, Bumba was in terrible pain. He retched and strained and vomited up the sun. After that light spread over everything. The heat of the sun dried up the water until the black edges of the world began to show. Black sandbanks and reefs could be seen. But there were no living things. Bumba vomited up the moon and then the stars and after that the night and its light also. Still Bumba our Creator was in pain. He strained once again and from his mouth nine living creatures came forth: the leopard named Koy Bumba and Pongo Bumba the crested eagle; the crocodile, Ganda Bumba, and one little fish named Yo; next, old Kono Bumba, the tortoise, and Tsetse, the lightning, swift, deadly, and beautiful like the leopard; then the white heron, Nyanyi Bumba; also one beetle; and the goat named Budi. The creatures themselves then created all the creatures. The heron created all the birds of the air. The crocodile made the serpents and the iguana. The goat produced every beast with horns. Yo, the small fish, brought forth all the fish of all the seas and waters. The beetle created insects. Then the serpents in their turn made grasshoppers, and the iguana made the creatures without horns.

Last of all came forth men. There were many men, but only one was white like Bumba. His name was Loko Yima.

Then the three sons of Bumba said they would finish the world. The first, Nyonye Ngana, made the white ants, but he was not equal to the task and died of it. The ants, however, thankful for life and being, went searching for black earth in the depths of the world and covered the barren sands to bury and honor their creator.

Chonganda, the second son, brought forth a marvelous living plant from which all the trees and grasses and flowers and plants in the world have sprung. The third son, Chedi Bumba, wanted something different, but for all his trying made only the bird called the kite.

Of all the creatures, Tsetse, lightning, was the only troublemaker. She stirred up so much trouble that Bumba chased her into the sky. Then mankind was without fire until Bumba showed the people how to draw fire out of trees. “There is fire in every tree,” he told them and showed them how to make the fire drill and liberate it. Sometimes today Tsetse still leaps down and strikes the Earth and causes damage.

When at last the work of creation was finished, Bumba walked through the peaceful villages and said to the people, “Behold these wonders. They belong to you.” Thus from Bumba, the Creator, the First Ancestor, came forth all the wonders that we see and hold and use and all the brotherhood of beasts and men.

Some scholars have noticed the detail that one of the men is described as being white in color, as is the god Bumba himself, and have suggested that this may imply that the story developed later, or at least was influenced later on, after the Bushongo people had encountered European colonizers. There is also a rather tantalizing correspondence between the beginning of the story with the creation story of in the Book of Genesis. But unfortunately because the original records come to us through Europeans, there are no records of what the story looked like prior to the arrival of Europeans, so it’s hard to tell if these elements were original to the Bushongo or adaptations that came about after their encounters with Europeans, and in particular, Christian missionaries.

Well, transient phenomena also did not escape the attention of African peoples. Comets, in particular, were noticed and as with virtually every other civilization, were considered to be very bad omens indeed. Particularly notable was the Great Comet of 1882 which initially appeared at very southern latitudes and was carefully observed in the Southern Hemisphere. The comet was rather remarkable because it belonged to a class of comets called “sungrazers” which come within one solar radius of the Sun’s surface and consequently get exceedingly bright, this one being visible in the daytime despite being so close to the Sun. Since the comet appeared around the time that European colonizers made it into the central Congo region, the Tabwa people later interpreted it as an omen of the colonizer’s arrival, and the resulting violence, famines, and epidemics that plagued them.

There are records of an even earlier comet sighted by the Zulu in the late summer of 1827 which influenced the trajectory of the Zulu Kingdom. The Zulu Kingdom grew in the early 19th century as a man named Shaka, one of the illegitimate sons of the Chief of the Zulus at the time, began to grow his clan of just a few thousand men to a massive army that conquered a substantial portion of southeastern Africa. Over the course of the early 1810s until his death in 1828 King Shaka instituted major changes in the organization and tactics used by the Zulu army. King Shaka emphasized strong discipline and high mobility of the army and seems to have changed the nature of warfare in southern Africa from a more ritualistic, bloodless style of warfare to one in which absolute conquest was the overriding objective. His impact on African warfare and politics is such that it has been seen as analogous to Napoleon’s impact on European warfare and politics.

Well, in late summer of 1827 a comet appeared in the sky, roughly coinciding with the death of King Shaka’s beloved mother, Nandi, likely from dysentery, though anti-Shaka factions pushed a long running rumor that the king himself had in fact stabbed his own mother to death. Either way, according to the surviving records, King Shaka ensured that his mother’s death was not merely a personal tragedy. At her funeral, the people lamented Nandi’s death and threw burning wood into the air at the comet that seemed to have brought her death about. Being of the highest royalty, members of her personal coterie were executed so that they could serve her in the afterlife. King Shaka then decreed a year of mourning during which he forbade anyone from planting crops, drinking milk, then one of the major sources of calories, and having sexual relations between a husband and wife. If a woman was found to be pregnant during this year she was executed alongside her husband. In all, it’s estimated that around 7000 people died, though it should also be said that the original sources of these events are from European colonists who, needless to say, had their own biases, so there is probably some level of exaggeration. At any rate, this enforced period of mourning did not endear him to the population and over the course of this year anti-Shaka factions led by his half-brothers were able to gain power and ultimately assassinated the king in 1828. But after a brief power struggle that ensued, the half-brother who ended up on top, King Dingane, turned out to be an even crueller leader than Shaka but lacked the military and political acumen that King Shaka had to make up for it. During his reign the Zulu Kingdom began to fragment as rebel chiefs broke away and this, in turn, weakened the Zulu Empire as they began to come into conflict with the Dutch Voortrekkers that had begun migrating northward into Zulu territory to escape British rule in South Africa. This conflict then came to a head during the Battle of Blood River which was a complete catastrophe for the Zulu. 480 Voortrekkers battled some 15,000 Zulu soldiers and in the end more than 3000 Zulu were killed with no deaths of the Voortrekkers.

But I am getting away from astronomy, so let’s move to a less bloody but still controversial topic: calendars. The Zulu calendar is fairly representative of the calendars of many of the peoples of Africa, so it is a good place to start. The Zulu, along with most other Bantu peoples and the Khoisan, observed a lunar calendar where new months were marked at the evening when a crescent was visible after new moon. The new year, however, was not determined astronomically, but officially arrived when the first big rains fell, usually around September. These rains would mark the time for ploughing and preparing for the next agricultural year. Nevertheless, although the new year began on the first day of rains, the Zulu, along with most other peoples of southern Africa, would prepare for it by watching for the heliacal rising of the Pleiades, which would typically precede the first rains by couple of weeks. This would allow them time to prepare for the new year. Now, as with any lunar calendar, there is the problem that 12 lunar months are 354 days long, but the year is 365 days long, so every now and again you need to add in an intercalary month. The Zulu have no formal system to determine whether or not to add an intercalary month for the year. Instead the people simply negotiate among themselves to decide. This kind of ad-hoc addition of intercalary months is quite common among societies with lunar calendars, but what is somewhat unique to the Zulu is that these kinds of negotiations are not done in a hierarchical way. Among the early Babylonians, for instance, intercalary months were added in an ad hoc way, but the decision was made by a small group of elites, the priests. But among the Zulu there is no special class of people who make this decision, it’s done in a decentralized way.

This principle of negotiating the calendar is taken to an extreme by the Mursi, an Afroasiatic people who live around the border between Ethiopia and Kenya. The Mursi have a calendar with 13 lunar months and are all very familiar with it. The first month of the year is called “gamwe,” and is the only one that has its own name. After that the months are simply called “bergu 1,” “bergu 2,” and so on through “bergu 12,” “bergu” just meaning “year.” So “bergu 2” means “the year is two months old.” Even very young children are able to tell you the character of the months, what kind of work gets done in each month, what kind of festivals there are, what the weather is like, and so on. There are two main landmarks in the year. The first landmark is the onset of the first “big rains,” which in these northern latitudes come around late March or early April. The Mursi live alongside a river called the Omo, and the second landmark comes six months later, when the upstream snow melt causes the river to flood. At this point the Mursi bifurcate. The women move to the banks of the river and cultivate crops there whereas the men move away from the Omo with the cattle. Knowledge of what time of the year it is is critical. If the Mursi women sow seeds too early in the year, later floods will come and wash the seedlings away. But if they wait too long and sow too late, the ground will have dried up and the seeds won’t sprout.

Now because the Mursi year has 13 lunar months, which is 383 and a half days, but the solar year has only 365 and a quarter days, there is a problem. Most cultures with a lunar calendar resolve this problem with intercalation — every now and again they explicitly add in an extra month into the calendars to get the months to line up with the seasons. But the Mursi instead solve this problem with what might be described as “fuzzing.” The Mursi are quite insistent that every year has 13 months in it, but if you ask someone what month it is right now, you will not get a straight answer. They will reply something to the effect of, “well, some say that it is Bergu 8, but others say that it is Bergu 9.” Everyone makes up their own mind as to what month it is and makes their case to their neighbors, but not everybody will be convinced. Ultimately, people simply agree to disagree about the month.

So then, how do you determine for yourself what month you think it is? The Mursi have a number of signs that they look to, but nothing is considered definitive. Some of these signs are seasonal events, like rains or hot days. But others are celestial. A few of the Mursi take a particular interest in regularly observing the heavens and will mark things like the heliacal rising of stars or the positions of sunrise and sunset, and they will marshal that as evidence that it is one month or another. In particular, one of the more important signs that they will look for is if the Sun is in what they call one of the two “houses,” that is, when it rises at its northernmost or southernmost points, which corresponds to the summer and winter solstices. But, as in modern day Western society, there is no special social status accorded to people who regularly observe the heavens, and any celestial markers they observe are just taken to be one piece of evidence among many during discussions about what month it is.

To Westerners, this ambiguity in the calendar might be rather perplexing, but it really comes out of a much older and more intuitive understanding of time than we have today in the West. Today, we in the West think of time in very precise, mechanical terms. If you close your eyes and think of the word “time,” you probably conjure up in your head an image of the second hand on a stopwatch ticking away. In the modern view, time is a progression of regularly repeating instants; a vast, impersonal, and mostly uninteresting canvas upon which the events of the world play out. But every one of these instants is equal to any other. Earlier, pre-modern notions of time are more event based. And, to get somewhat philosophical, this is still true today, it’s just that the events we consider are cold, impersonal things like the oscillations of a cesium atom or vibrations of a quartz crystal. But pre-modern conceptions of time generally took it for granted that these events had to have some relevance to one’s life. And because these events are often not discrete things, the beginnings and ends of time periods can be a little bit fuzzy in the eyes of modernity. Nevertheless, this older conception of time is so intuitive that we still have it around today. For instance, you might want to go apple picking some time during apple season. But when is apple season? Well, you have some idea — the middle of October probably falls within apple season but early July does not. But what about early September? Late August? December? The boundaries are a little fuzzy. Or suppose you say to a friend that you heard a loud noise outside that woke you up in the middle of the night. When is the middle of the night? It’s not midnight exactly. Everyone has some notion of it, 3am would certainly count, but again the boundaries are a little bit fuzzy. If the noise woke you up at 5am, would that be the middle of the night? Probably not, but 4am? Well, perhaps. Around the boundaries, some people will call it one way, others another, just as the Mursi do. And this kind of fuzziness is still with us with one of the most fundamental cycles we experience: the seasons. Everyone knows what the seasons are, but when do they begin or end? In modern times we’ve tried to delineate it with specific days, but even here there are conflicting definitions. The astronomical seasons are set by the solstices and equinoxes. Summer starts on the summer solstice, sometime around June 21. But the meteorological seasons begin from the start of the calendar months, so summer starts on June 1. Then the solar seasons begin on the cross-quarter days, halfway between the solstices and equinoxes, so summer would begin on May 1. In fact, this is the older definition that was used, which is why the old term midsummer, think Shakespeare’s A Midsummer Night’s Dream, refers to a time around the summer solstice, even though in the astronomical definition, this is the start of summer, not the middle of it. At any rate, this confusion comes about from trying to squeeze a messy, imprecise pattern of natural events into a rigorous 365 and a quarter day annual calendar. But we all have the experience of walking outside one day maybe in early June, maybe a little later, when the sun is blazing, the weather is hot, the flowers have faded and everything is green and we think, “Yes, today is the first day of summer.”

The Borana people somewhat southeast of the Mursi also have a rather unique calendar. Like the Mursi, there is a small fraction of people who take an interest in observing the heavens and are considered to be experts in astronomy, called “ayantu.” And as with the Mursi and the modern day West, there is no special social status for this skill. Generally, knowledge of astronomy is passed down through the generations from father to son. The Borana have 12 lunar months, and as with most lunar calendars they mark the new month at the first sighting of the lunar crescent after new moon. Each month has either 29 or 30 days, but only the first 27 days get unique names. Once they get to the 28th day, they start over again and repeat the first two or three names. The ayantu mark the days and months by observing which stars or asterisms the Moon is next to when it rises. Since the Borana live very close to the equator, the stars rise almost exactly vertically, and looking at what stars are to the left or right of the Moon essentially tells you the right ascension of the Moon. Some months will have 29 days and others 30, and the Borana will decide whether or not to add the extra day when they see that the Moon has gotten too far out of step with the corresponding stars that it is supposed to rise with towards the end of the month. Similarly, the ayantu will sometimes add an intercalary month when they see that the day that a particular month begins on has gotten too far out of step with the corresponding stars it rises with at the beginning of a month. So the Borana calendar is a rare example of a luni-stellar calendar where time is kept by keeping track of the position of both the Moon and the stars, rather than the much more common lunisolar calendar that most other civilizations use. So the Borana are rather unique in that they do not consider the position of the Sun at all in their timekeeping. Instead, thanks to their proximity to the equator, it is easier, and probably more accurate, to rely on the stars.

Well, there is much more to say about the astronomy of sub-Saharan Africa, but this episode is late enough as it is, so we will have to leave the region behind for now and travel up the Nile. Next month I will return to the promise I made two months ago and talk about the astronomy of one of the world’s oldest civilizations: Egypt. I hope you’ll join me then. Until the next full moon, good night and clear skies.

Additional references

  • Ruggles, Handbook of Archaeoastronomy and Ethnoastronomy
  • Holbrook, African Cultural Astronomy
  • Alcock, Venus Rising