Ancient Egyptian Astronomers Recorded Eclipse of Binary Star Algol – 3000 Years Before Modern Astronomers

Here’s a comprehensible summary of this recent academic paper that proposes Egyptian astronomers successfully recorded the eclipse period of a distant star.

Here’s an excerpt of the summary:

Egyptian astronomers used what they learnt to make predictions about the future. They drew these up in the form of calendars showing lucky and unlucky days.

The predictions were amazingly precise. Each day was divided into three or more segments, each of which was given a rating lying somewhere in the range from very favourable to highly adverse.

One of the best preserved of these papyrus documents is called the Cairo Calendar. Although the papyrus is badly damaged in places, scholars have been able to extract a complete list of ratings for days throughout an entire year somewhere around 1200 BC.

An interesting question is how the scribes arrived at their ratings. So various groups have studied the patterns that crop up in the predictions. Today, Lauri Jetsu and buddies at the University of Helsinki in Finland reveal the results of their detailed statistical analysis of the Cairo Calendar. Their conclusion is extraordinary.

These guys arranged the data as a time series and crunched it with various statistical tools designed to reveal cycles within it. They found two significant periodicities. The first is 29.6 days–that’s almost exactly the length of a lunar month, which modern astronomers put at 29.53059 days.

The second cycle is 2.85 days and this is much harder to explain. However, Jetsu and co make a convincing argument that this corresponds to the variability of Algol, a star visible to the naked eye in the constellation of Perseus.

So, why post this on PaleoBabble? Basically, because of this post from the Daily Graal suggesting that this discovery will dredge up talk of the “mystery” of the Dogon’s knowledge of Sirius.

As readers know, I think there is zero evidence in support of ancient astronaut visitation of the Dogon, primarily because recent research has demonstrated that the theory is based on the word of one Dogon, whose story and mythology is unknown and unconfirmed by other Dogon elders (for starters).

But should I reconsider ancient astronauts in light of this discovery?

Uh … no. Did you read the excerpt above?  Read it again. The Egyptians did what they did using two very human techniques: (1) naked eye astronomy (“the variability of Algol, a star visible to the naked eye in the constellation of Perseus“) and (2) a little thing we earthlings call math.

Sorry. No aliens needed for this either. But it’s pretty cool — and shows once again how much we underestimate the ancients.


20 thoughts on “Ancient Egyptian Astronomers Recorded Eclipse of Binary Star Algol – 3000 Years Before Modern Astronomers

  1. Don’t worry, somebody will find a way spin it. It’ll be on Ancient Aliens in a month with the usual suspects commenting. Sad, but true.

  2. The myth of the nommo sounds like a description of Mahktesh Ramon and the mountain of ammonites (some as large as tractor wheels).

  3. I am not sure I understand what you mean by “reference”. A makhtesh is an actual geomorphic feature that is unique in all the world to the Negev. It resembles an impact crater but was formed by an upper crust of hard rock (limestone) collapsing onto a basin of softer sandstone. The soft rock was obviously a Sinemurian sea because of the type fossils found there. In the Dogon myth, Amma created a pool of water and sent Nommo to live there. All the elements of this myth could be describing the mountain of ammonites in the basin of the makhtesh crater. BTW, Nommo resembles a scarab beetle and was reborn from a ball of rolled earth (Khepre?). Ammonites and the pupae of scarab beetles look very much alike. This is just my own observation so I don’t really have a reference.

    • My bad – that wasn’t worded very clearly. I meant some sort of definition and scholarly reference for that definition. You’ve given half of that here. I’m not sure there is any coherence to a connection with the Dogon (or that you are even arguing for one). Any visual “correlation” amounts to a Rohrschach approach. Visual similarity doesn’t mean anything. But again, I can’t say I’m certain that is what you’re saying.

  4. The evidence I have (numismatic, linguistic and textual) links the scarab to the ammonite. The evidence of a connection between the nommo of the Dogon myth and the ammonite is just my personal observation and I have no scholarly reference.

  5. No I don’t have scholarly references. BTW, in biblical scholarship circles, is it widely known that there is a mountain made completely of ammonite fossils in the Wilderness of Zin? Thank you for your reply.

    • And the relevance is …? (And I’d still want sources for this “widely known” fact; biblical scholars aren’t generally geologists; I like actual published data when something is under scrutiny / discussion). That shouldn’t be hard to find with all the article databases out there, along with the internet).

  6. Thank you for your reply. If lexicon is a result of the social environment as well as the physical environment then the geography of a region is very important to understanding ancient autochthonous language of the Old Testament. Considering the mythic importance of the ammonite, the mountain made entirely of these fossils in the region of Israelite wanderings should be of interest to biblical scholars.

    The following is an article found on a numismatic website.

    A countermarked coin described here provides evidence that ancient Greeks created artistic portrayals of ammonite fossils, although they probably valued them more for their religious significance rather than for their significance for the study of natural history. The host coin (Figure 1) is composed of bronze or other base metal (weight = 6.816g), and is 20mm in diameter at its widest point. The obverse is in very good to fine condition and shows a diademed male head facing right. The reverse of the coin is largely obliterated, partly by extended wear and/or a weak strike and partly by flattening due to the impact of the relatively large countermark that was applied to the obverse. The coin is in a private collection and has been listed by Mark McMenamin at the Mount Holyoke College Museum of Art.



    The countermark (Figure 2), 8.5mm in diameter, is in very fine condition and shows a serially partitioned spiral pattern. The spiral makes approximately two revolutions. The partition lines are either perpendicular to the edge of the spiral or slightly inclined to it. The countermark pattern was apparently intended to portray the cornua ammonis or Ammon’s horns. These fossils were referred to by Pliny the Elder (c. AD 77) in his Natural History (37.167): ‘Cornua ammonis or horn of Ammon, one of the most sacred stones of Ethiopia, has a golden yellow colour and a shape resembling that of the horn of a ram.’ Pliny’s reference to a golden yellow colour identifies the fossils he was observing as preserved as calcitic casts and moulds, which typically manifest a honey-yellow colour in the calcitic infillings. Mayor (2000: 275) inferred that the fossils referred to by Pliny were iridescent ammonite fossils. The fact that the identification of ammonite fossils with the horns of Ammon was known to Roman artists is suggested by the portrayal of Zeus Ammon in Figure 3.

    Pliny may also have made reference to ammonite fossils in his description (Natural History 11.36) of rocks from Egypt’s Eastern Desert. Pliny called rocks with markings resembling snakes ophites. More specifically, his Augustean ophites were rocks with markings that ‘curl over like waves so as to form coils.’ Harrell (1995) interprets Augustean ophites as saussuritised gabbros from the Roman quarry at Wadi Semna, but a better interpretation of Augustean ophites is as fossil ammonites.

    The provenance of the host coin is dearly Greek, based on its artistic style and the style of the planchet from which it was struck. Numismatist Andy Metz believes the coin to be Thracian, and this is a reasonable suggestion but is not the only possibility. Its find site was reported as ‘found in the Black Sea area” (Andy Metz, written communication, 28 February 2004). The coin is most similar to Sear 4335, a bronze coin minted in Kalzomenai in the second-first century BC. This tentative identification is supported by the reverse of the countermarked coin which shows a seated figure on the left with a right raised hand, similar to the reverse of Sear 4335 which shows Anaxagoras seated on the left with a right hand raised. Unfortunately no epigraphy remains on the countermarked coin to confirm the identification, so it must remain uncertain for the present. The host coin’s style, however, is quite in accord with a date of second-first century BC.


    The provenance of the countermark is likewise uncertain, but again a Greek origin is assumed. This countermark is unlike any known to occur on Phoenician coins (McMenamin 2000). It also appears that the countermark was roughly contemporary with the coin rather than being a much later addition. The countermark could simply represent a tightly coiled ram’s horn. Indeed, bronze coins minted in Klazomenai between the fourth-first centuries BC frequently portray rams or ram’s heads (e.g. Sear 4318, 4322, 4323, 4326-29, 4332, 4334). A disembodied horn is unusual, however. If it had been intended to be solely a ram’s horn/Ammon’s horn, the person striking the countermark would have placed the marking at the side of the head of the male bust, rather than striking it at the nape of the neck as was done. Thus the image more likely represents a portrayal of an actual fossil ammonite.

    This interpretation does not preclude an association between the spiral countermark and the cult of Zeus Ammon. This cult (which originated in Egypt with the Egyptian diety Amun, the ‘hidden one’) enjoyed a phase of great popularity with the Greeks as well as non-Egyptian peoples of third-century BC Africa, such as the Garamantes (Keys 2004). Alexander the Great made a special point of visiting the oasis of Siwa in North Africa (south-west of Nitria in Egypt), and was acclaimed in the Siwa Temple as a son of this god. Alexander is portrayed on some of his coins as bearing the horns of Zeus Ammon, and he is known in this guise as two-horned Alexander or Alexander Dulkarnayim. Evidently it was Alexander himself who commissioned this iconography, for the Horn of Ammon is visible on a gold medallion from the Mir Zakah hoard in Afghanistan, revealing that Alexander had proclaimed himself a god (Holt 2003; 2006). Later art took this image as an embodiment of evil, as in the head of Satan as portrayed by Giorgio Vasari in his 1540-41 Allegory of the Immaculate Conception (Plate 685 in Andres et al. 1994). The Ammon horns are exchanged for more typical devil horns in a 1541 small-scale replica of The Immaculate Conception (Plate 278 in Gregori 1994) by the same artist.

    Strabo (born c. 64 BC) in his Geography (1.3.4) notes, ‘By the Temple of Ammon [at Siwa] and for 3000 stadia along the road to the temple there are great masses of oyster shells.’ Most of these fossils were probably Cenozoic in age and so would not be expected to contain ammonites, although outcrops of Mesozoic marine strata occur in the area as well. Kirchheimer (1977), following suggestions by Fourtau (1899) and Blanckenhorn (1901), argued that Pliny’s cornua ammonis were in fact large Paleogene specimens of the gastropod Natica rather than ammonite fossils.

    Howgego’s (1985) compendium of Greek imperial countermarks illustrates no countermark resembling the one described here. It seems reasonable to conclude, then, that the countermark: predates Roman administration of the area; dates to the fourth-first centuries BC, and was meant to portray an ammonite fossil, possibly in connection with the cult of Zeus Ammon.

    • You’ll have to pardon me, here, but I don’t see the relevance of this to anything. So, if I was holding an ammonite stone in my hand something mystical would happen to me? THAT is what I want scientific verification for, not mythology.

    • No. This is a very famous mistranslation, well known to scholars (it’s often used in courses in textual criticism, as it derives from a text-critical / manuscript error).

  7. Scholars speculate that Jacob would have traveled via the Kings Highway from Beersheva to Haran. The first leg of this journey would have been the Akrabim passage which is located just south of the Makhtesh. Stopping to rest the first night he used a stone “found in this region” for a pillow. It is implied that it was this stone that caused him to have a dream. He dreamed of a stairway to heaven in which emissaries of the Lord were ascending and descending. It has been suggested (by published scholars) that this stairway was a ziggurat.

    The following are observations that I have found meaningful surrounding this myth.
    1. Pliny has written that ammonites are holy stones and cause prophetic dreams.
    2. “found in this region” implies a unique type of stone.
    3. Ammonites are virtual blueprints of ziggurats.
    4. Horeb, akrabim and cherub share same trilateral root.
    5. There is no evidence that more scorpions reside in this region than in any other.

    • On number 1, Pliny wrote a lot of things that were pure nonsense. Read Mayor’s book, The First Fossil Hunters, for a catalogue of those items. That Pliney said something carries no weight, especially when he got so many things wrong due to his own superstitions (common during his time).

      2. “Found in this region” is not specific language. “Region” is simply the word maqom, which means “place” — and could refer to something a few square feet wide, to much larger. It is utterly ambiguous, and so any point based on it is specious.

      3. Blueprints? Really? Source, please.

      4. Big deal

      5. Which means there is evidence of lots of scorpions in the area – and others.

      Boy, this is all an amazing stretch.

  8. The author of the article on ancient coins makes a compelling argument for depictions of ammonite fossils representing the horns of Ammon.

    Scientific verification for a mystical event is, obviously, impossible. Mystical events are impossible. Anything that defies physics is impossible. I thought this was a debunking website? I was offering a plausible geologic explanation for the origin of biblical myths.

    Of course Pliny did not understand the origin of fossils. He was merely recording the common view held by people of his era.

    Of course Moses did not have horns. The fact that Alexander issued coins depicting himself with horns after conquering the Sinai is not irrelevant. Everytime KhRN is used in the OT it is describing HORNS.

    The maqom of the route of the mythical Jacob traveled to Haran is extremely specific. Why would you say it is not? It has been the same for thousands of years. Are you saying the route of the Kings Highway or the descent of the Akrabim is unknown?

    I agree that scorpions are everywhere in the Negev. It has been suggested that this area has a preponderance and that is why it was so named which is folklore.

    Identical trilateral roots suggest a common word origin. How is it you do not know this?

    “Blueprint” was obviously a poor choice of words with you. Apparently, I am not allowed to have an opinion. Any opinion you will accept must come from a scholar. The problem I have is that a superstitious explanation is acceptable and even preferable to most biblical scholars. There were no ancient aliens and no finger of god writing on tablets of stone.

    • You don’t understand the issue with the Moses passage. The issue isn’t qeren; it’s that qeren here is either not a noun, but a verb meaning “to shine” (less likely), or (more likely), this usage is parallel to Habakkuk 3:4 (“His brightness was like the light; rays flashed ([Hebrew, qarnayim, our word in question] from his hand; and there he veiled his power”). When horns grow out of someone’s hand, let me know. Until then, the word pretty obviously refers to rays of light. As Sarna noted:

      A unique phenomenon conveyed by a unique Hebrew verb, karan. The traditional meaning given here is favored by the context and by Habakkuk 3:4 in which karnayim, “rays of light,” appears in parallelism with “a brilliant light.” This reference relates to God, and numerous biblical passages bear witness to a widespread, poetic notion of God being enveloped in light.? source: Nahum M. Sarna, Exodus (English and Hebrew; commentary in English.; The JPS Torah commentary; Philadelphia: Jewish Publication Society, 1991), 221..

      You didn’t answer my question – so if I snuggle up to an ammonite rock will something happen to me? Where’s the science?

  9. I understand very well. Ammonite horns as a symbol of divinity is very well documented It seems that scholars are divided on the issue of Moses with horns.For a condensed synopsis see

    If you snuggle up to an ammonite, as I propose Jacob did, nothing will happen to you. The reason is because IT IS A MYTH. I am beginning to think that you are arguing from a literal hermeneutic position.

  10. There are no cognates for ray or emanating light in any related language that are derived from the trilateral root of horn.

    • you don’t need cognates if you have a homonym in the language. Usage within a language is preferred over cognates anyway. (That is, the language gets to dictate how the language uses a word). If a biblical writer wants to use qeren as a metaphorical “extension of light” there is no rule that he can’t do so.

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