Ancient Babylonian and Mesopotamian Astronomy | Middle East And North Africa

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MESOPOTAMIAN ASTRONOMY

Babylonian tablet recording Halley's comet

The Mesopotamians invented astronomy. A Sumerian cuneiform tablet in the British Museum describes the sighting on an exploding star in 4000 B.C. Modern astronomers have found the remnant of a star that may have exploded at that time.

In ancient times astrology and astronomy were the same thing. Astrology as we know it originated in Babylon. It developed out of the belief that since the Gods in the heavens ruled man's fate, the stars could reveal fortunes and the notion that the motions of the stars and planets control the fate of people on earth. The motions of the stars and planets are mainly the result of the earth’s movement around the sun, which causes: 1) the sun to move eastward against the background of the constellations; 2) the planets and moon to shift around the sky; and 3) causes different constellations to rise from the horizon at sunset different times of the year.

Websites on Mesopotamia: Internet Ancient History Sourcebook: Mesopotamia sourcebooks.fordham.edu ; International Association for Assyriology iaassyriology.com ; Institute for the Study of Ancient Cultures, University of Chicago isac.uchicago.edu ; University of Chicago Near Eastern Languages and Civilizations nelc.uchicago.edu ; University of Pennsylvania Near Eastern Languages & Civilizations (NELC) nelc.sas.upenn.edu; Penn Museum Near East Section penn.museum; Ancient History Encyclopedia ancient.eu.com/Mesopotamia ; British Museum britishmuseum.org ; Louvre louvre.fr/en/explore ; Metropolitan Museum of Art metmuseum.org/toah ; Ancient Near Eastern Art Metropolitan Museum of Art metmuseum.org; Iraq Museum theiraqmuseum ABZU etana.org/abzubib; Archaeology Websites Archaeology News Report archaeologynewsreport.blogspot.com ; Anthropology.net anthropology.net : archaeologica.org archaeologica.org ; Archaeology in Europe archeurope.com ; Archaeology magazine archaeology.org ; HeritageDaily heritagedaily.com; Live Science livescience.com/

Babylonian Astronomy

The Babylonians excelled at astronomy. Many of the constellations that we see in the sky were first categorized by them. Credited with some of the first correct astronomical observations, they kept careful records and recorded celestial events under the belief they could shape future events. Under Hammurabi the Lawgiver, in 1800 B.C., star catalogs and planetary records were compiled. The Neo-Babylonian used ziggurats as observatory and mapped the night time sky into constellations. They developed the 12 signs of the zodiac, recorded the motions of the planets and even predicted eclipses.

The ancient Babylonians knew that the length of the solar year was approximately 365.4 days and had divided the period of 24 hours into 12 beru (double hours) in accordance with the divisions of the equator, each of which was divided into 60 minutes, and each minute into 60 seconds. Such data were recorded on clay tablets in the library of the Babylonian king Assurbani-pal, around 668 B.C. [Source: Encyclopedia of Occultism and Parapsychology, Encyclopedia.com]

Larry Freeman wrote in his Astronomy & Navigation Page: “The Babylonians noticed that they had to adjust their observations every day. Their calendar had 12 months of 30 days and 5 year end holidays giving 365 days a year. It was hard to compute fractions of 365 (they did not have multiplication or division) so they used 360 as the number of days for astronomy. They divided a circle into 360 parts so by setting it back one part every day they could keep the observations of the stars constant from one day to the next (within 1.5 percent). The number 360 is 345*6 which give a great many factors and therefore great for doing ratios. This is where we got 360 degrees in a circle. Note: Modern day observers use {1/364.24219889 - .0000000614(t-1900) — sidereal time} to adjust their observations. The Babylonians were less than 1.5 percent off or about 5 degree per year. This was good since there were no accurate way to keep time in those days. The would occasionally adjust their based on the helical rising of certain stars. These are the stars that would just have risen in the area of the sun when the sun rises. [Source: Larry Freeman's Astronomy & Navigation Page]

Illumination of Bel

One ancient Mesopotamian library contained a 72-book volume on astrology called “The Illumination of Bel.” In it the study of astrology was intermixed with that of astronomy. The heavens had been mapped out and the stars named; the sun's course along the ecliptic had been divided into the twelve zodiacal signs, and a fairly accurate calendar had been constructed. Hundreds of observations had been made of the eclipses of the sun and moon, and the laws regulating them had been so far ascertained that, first, eclipses of the moon, and then, but with a greater element of uncertainty, eclipses of the sun, were able to be predicted. [Source: “Babylonians And Assyrians: Life And Customs”, Rev. A. H. Sayce, Professor of Assyriology at Oxford, 1900]

One of the chapters or books in the “Illumination of Bel” was devoted to an account of comets, another dealt with conjunctions of the sun and moon. There were also tables of observations relating to the synodic revolution of the moon and the synodic periods of the planet Venus. The year was divided into twelve months of thirty days each, an intercalary month being inserted from time to time to rectify the resulting error in the length of the year. The months had been originally called after the signs of the zodiac, whose names have come down to ourselves with comparatively little change. But by the side of the lunar year the Babylonians also used a sidereal year, the star Capella being taken as a fixed point in the sky, from which the distance of the sun could be measured at the beginning of the year, the moon being used as a mere pointer for the purpose.

At a later date, however, this mode of determining time was abandoned, and the new year was made directly dependent on the vernal equinox. The month was subdivided into weeks of seven days, each of which was consecrated to a particular deity. These deities were further identified with the stars. The fact that the sun and moon, as well as the evening and morning stars, were already worshipped as divinities doubtless led the way to this system of astrotheology. But it seems never to have spread beyond the learned classes and to have remained to the last an artificial system. The mass of the people worshipped the stars as a whole, but it was only as a whole and not individually. Their identification with the gods of the state religion might be taught in the schools and universities, but it had no meaning for the nation at large.

Astronomy Observations for the Assyrian King

Astronomers sent letters to the Assyrian king on the results of their observations. Among the letters published by Professor Harper is an interesting one — unfortunately defaced and imperfect — which was sent to Nineveh from one of the observatories in Babylonia. After the ordinary compliments the writer, Abil-Istar, says: “As for the eclipse of the moon about which the king my lord has written to me, a watch was kept for it in the cities of Akkad, Borsippa, and Nippur. We observed it ourselves in the city of Akkad.” Abil-Istar then goes on to describe the progress of the eclipse, but the lines are so broken as to be untranslatable. [Source: “Babylonians And Assyrians: Life And Customs”, Rev. A. H. Sayce, Professor of Assyriology at Oxford, 1900]

When the text becomes perfect again we find him saying that he had written an exact report of the whole occurrence and sent it in a letter to the King. “And whereas the king my lord ordered me to observe also the eclipse of the sun, I watched to see whether it took place or not, and what passed before my eyes I now report to the king my lord. It was an eclipse of the moon that took place.… It was total over Syria and the shadow fell on the land of the Amorites, the land of the Hittites, and in part on the land of the Chaldees.” We gather from this letter that there were no less than three observatories in Northern Babylonia: one at Akkad, near Sippara; one at Nippur, now Niffer; and one at Borsippa, within sight of Babylon. [Source: “Babylonians And Assyrians: Life And Customs”, Rev. A. H. Sayce, Professor of Assyriology at Oxford, 1900]

As Borsippa possessed a university, it was natural that one of the three observatories should be established there. As nothing is said about the eclipse of the sun which the astronomers at the Assyrian court had led the King to expect, it is probable that it did not take place, or at all events that it did not occur so soon as was anticipated.

Mesopotamian Astronomy and the Planets

piece of a planisphere

Morris Jastrow said: “In regard to the planets, there are reasons for believing that Jupiter and Venus were the first to be clearly differentiated, Jupiter by virtue of its brilliant light, Venus through the striking fact that it appeared as an evening star during one part of the year, and as morning star during another. In the astrological system Jupiter was identified with Marduk, who, we have seen, became the chief god of the pantheon after the Hammurabi period; and Venus with the chief goddess Ishtar. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911 ]

In early 2016, it was announced that deciphered ancient Babylonian clay tablets showed that their astronomers were more advanced than previously thought — using geometric calculations to predict the motion of Jupiter. Scholars had assumed it wasn’t until almost A.D. 1400 that these techniques were first employed — by English and French mathematicians. [Source: Daniel Weiss, Archaeology magazine, May-June 2016]

““No one expected this,” said Mathieu Ossendrijver, a professor of history of ancient science at Humboldt University in Berlin, noting that the methods delineated in the tablets were so advanced that they foreshadowed the development of calculus. This kind of understanding of the connection between velocity, time and distance was thought to have emerged only around 1350 AD. The methods were similar to those employed by 14th century scholars at University of Oxford's Merton College, Professor Ossendrijver said. [Source: Rob Waugh, Yahoo News UK, November 27, 2019]

Venus and Mesopotamian Astronomy

Morris Jastrow said: ““For Venus we have, at the outset, the distinction between her appearance as an evening star and as a morning star. Elaborate tables were prepared, based on observation, or drawn up after a conventional pattern, noting the time of her heliacal rise as morning star, the duration of visibility, the time of her setting, the length of time during which she remained “hidden in the heavens,” as runs the astrological phrase, and the day and month of her reappearance as evening star. To each entry the interpretation was attached, and this varied according to the length of time that Venus was visible, and the character of the month wherein she reappeared. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911 ]

“These long lists, worked out in great detail, again illustrate the purely empirical character of such astronomical knowledge as the Babylonians and Assyrians possessed, down at least to the sixth century B.C. For instance, the period, according to scientific investigation, between the heliacal setting of Venus and her heliacal rise is seventy-two days; but in the Babylonian-Assyrian astrological texts, thejperiod varies from on e jnpnth to five m flnfchs=-too short on the one hand, and too long on the other. In order to account for such discrepancies, we must, perforce, assume that the observations were defective —for which there is indeed abundant evidence—and that the lists, being composite productions of various periods, embody the errors of earlier ages incorporated in the more accurate records of later periods, though even these too were based upon merely empirical knowledge.

“But whatever be the explanation, the ignorance of the Babylonian and Assyrian astrologers is patent; and the infantile fancies which frequently crop out in these astrological texts keep pace with the ignorance. Thus, the peculiar scintillations of Venus, when particularly bright, gi ve to her outline the appearance of rays. When these rays were observed, Venus was said to “have a beard,” and when the sparkling edges faded in lustre, Venus was said to have “removed her beard.” Venus with a “beard” was in general favourable, while Venus without a beard was in general unfavourable, though here, too, the interpretation varied according to the month in which the “beard” was put on, or taken off. When the rays appeared over Venus, she was recorded as “having a crown,” and a distinction was made between a “sun” crown and a smaller one, a “moon” crown,or crescent,—all of which illustrates the naivete of their astronomical explanations even while revealing their anxiously close observations.

Saturn, Mercury, Mars and Mesopotamian Astronomy

Morris Jastrow said: ““The remaining three planets—Saturn, Mercury, and Mars—were at first combined in the designation Lu-Bat, which became the general term for “planet.” The term conveys the idea that the movements of these planets were observed for the purpose of securing omens, but, originally, either Saturn, or Mercury, or Mars was meant when the movement or the position of a Lu-Bat was referred to. This circumstance carries with it the plausible conclusion that, before the three planets were more sharply differentiated from one another, the interpretation given to phenomena connected with any one of them was the same as that given to the others. The reason, no doubt, for thus grouping the three into one class was the difficulty involved in observing their separate courses. They bore no specially striking features, such as Jupiter or Venus possessed, and this was, also, no doubt, a cause which led to their being at first put upon the same plane. Of the three, Saturn appears to have been the first to be more definitely differentiated from the others. At all events, in the completed system Saturn was placed above Mercury and Mars. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911 ]

“It received the designation of the “steady’' Lu-Bat because of the slowness and regularity of its movements. Requiring about twenty-nine and a half years for the revolution in its orbit, Saturn is visible for a longer continuous period than Mercury or Mars. Possibly by an association of ideas that might occur to them but not to us, Saturn was also looked upon as a kind of second sun — a smaller Shamash by the side of the great Shamash of the day. Was there, perchance, a "learned theory” among the astrologers that the illumination of the night was due to this inferior sun of the night, which, because of its prolonged presence, seemed more likely to be the cause thereof than the moon, which nightly changed its phase, and even totally disappeared for a few days each month? It would verily seem so; but, at all events, the fact that Saturn was also called the “sun” is vouched for, both by explanatory notes attached to astrological collections, and by notices in classical writers to that effect. As one of these writers has it, “Saturn is the star of the sun” —its satellite, so to speak, and alter ego.

“This association of Saturn with the sun may have been a reason for identifying Saturn with a solar deity, Ninib, who, it will be recalled, was the sun-god of Nippur, and only second in rank to Enlil after this “intruder” displaced Ninib from the actual leadership of the pantheon which he once occupied. Ninib, accordingly, is well fitted to be the associate and “lieutenant” of Shamash, the paramount sun-god from a certain period onward.

“Next in importance to Saturn comes Mars, which, in contrast to Saturn exerting, on the whole, a most beneficent influence, was the unlucky planet. This unlucky and downright hostile character of Mars is indicated by his many names: such as the “dark” Lu-Bat; “pestilence”; the “hostile” one; the “rebellious” one; and the like. He was appropriately identified with Nergal, the sun-god of Cuthah, who, in the process of differentiation among the chief solar deities of Babylonia, became the sun of midsummer, bringing pestilence, suffering, and death in its wake; in contrast with Ninib who was viewed more particularly as the sun-god of the spring, restoring life and bringing joy and gladness. In the systematised pantheon, it will be recalled, Nergal was regarded as the grim god of war, and also as the deity presiding over the nether world—the Pluto of Babylonia, who, with his consort Ereshkigal, keeps the dead imprisoned in his gloomy kingdom. The association of ideas between Nergal, the lord of the “dark” region, and the dark-red colour of Mars may be regarded as an element of the identification of Mars with Nergal, just as the ideas associated with the colour red—suggesting blood and fire—furnished the further reason for connecting ill-boding omens with the appearance of Mars, and with his position relative to other planets and stars. As an unlucky planet, the “stronger” Mars appeared to be in the heavens, the more baneful his influence. Hence the brilliant sheen of the planet —in contrast to what we have seen to have been the case with Jupiter-Marduk—augured coming misfortune, while the “faint” lustre, indicating the weakness of the planet, was regarded as a favourable sign.

“The least important of the planets in Babylonian-Assyrian astrology is Mercury. Because of its nearness to the sun, it is less conspicuous than the others, and the most difficult to observe, and was, therefore, termed the “faint” planet. It is also visible for the shortest period. It can be seen with the unaided eye for only a little while, either shortly after sunset or before sunrise, and only during a part of the year. In northern climes even these restricted glimpses are not always accorded, and Copernicus is said to have regretted on his death-bed that he had never actually seen Mercury. As the least significant of the planets, there was not the same reason to distinguish Mercury by a specific designation, and hence, instead of being always referred to as the “faint” planet, it is just as often termed simply Lu-Bat, not in the sense of being the one planet of all others as was at one time supposed, but simply as a planet having no special distinction. Mercury as Lu-Bat is, as it were, the relict of the planets, the one left over of the group, the Cinderella among the planets, relegated to an inferior position of relative unimportance and neglect. Because of its smaller size and of its associations, Mercury is identified with the god Nebo, who in the systematised pantheon, it will be recalled, was the son of Marduk, and the scribe in the assembly of the gods, the recorder of the decrees of the divine court, and also the court messenger.

“The designation of Mercury as Lu-Bat indicated that Mercury summed up the essence of the powers attributed to the planets in general, so that even in the latter-day astrology, which survived the revolution of thought brought about by the natural sciences, Mercury is still associated with the soul— the seat of all vitality. In Babylonian-Assyrian astrology Mercury is a planet of a favourable nature. Its appearance is in almost all cases a good omen. The interpretations fluctuate with the months in which the planet is seen, but frequently refer to abundant rains and good crops.”

Stars and Mesopotamian Astronomy

Morris Jastrow said: “The scope of Babylonian-Assyrian astrology was still further extended by the inclusion of the more conspicuous stars and constellations, such as the Pleiades, Orion, Sirius, Aldebaran, the Great Bear, Regulus, Procyon, Castor and Pollux, Hydra, and others. The omens deduced, however, from constellations and single stars were dependent, primarily, upon the position of these constellations and stars relative to the planets. According as the planets approached or moved away from them, the omen was regarded as favourable or unfavourable, and the decision was again dependent upon their own associations. Thus, if Venus passed beyond Procyon, it pointed to the carrying away of the produce of the land; if she approached Orion it prognosticated diminished crops, —a meagre yield from palms and olives. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911]

“With a realisation of the fact that the sun and planets move in well-defined orbits, the need of distinguishing the exact position occupied at any given moment by any of those bodies naturally became pressing. The ecliptic, known as the “pathway of the sun,” was divided into three sections, each designated for one of the deities of that theoretically accepted triad which summed up the powers and subdivisions of the universe. These sections were known as the paths of Anu, Enlil, and Ea respectively. Each of these sections was assigned to a country, the Anu section to Elam, the Enlil section to Akkad, and the Ea section to Amurru. Elam lying to the east of the Euphrates Valley, and Amurru lying to the west, Akkad was in the middle between the two. According as a planet in its course stood in one division or an other, the omen was supposed to have special reference to the land in question. Thus the planet Venus, when rising in the division of Ea, portended that Amurru would have superabundance, if in the division of Anu that Elam would be prosperous, and if in the division of Enlil that Akkad would be benefited. In like manner, if Venus reached her culmination in the division of Anu, Elam would enjoy the grace of the gods, if in the division of Enlil, then Akkad, and if in the division of Ea, Amurru would be so favoured.

“This threefold division of the ecliptic does not appear, however, to have been an indication sufficiently precise of the position of the planet; accordingly, the stars near the ecliptic were combined into groups, and designations more or less fanciful were given to them. In this way, twelve such groups were gradually distinguished, corresponding to our constellations of the zodiac, though, it should be added, there are no indications that the Babylonians or the Assyrians divided the ecliptic into twelve equal divisions of 30° each. Retaining the division of the ecliptic into three equal sections, they distributed constellations among these sections as a further means of specifying the position of a planet at any moment, and also as an enlargement of the field of astrological divination. From symbols on the so-called boundary stones, it appears that up to ca. 1000 B.C., only four or five constellations in the zodiac were distinguished, and we must descend to the Persian period before we find the full number twelve marked out along the ecliptic. Undoubtedly, the enlargement of four or five to twelve—for which there seems no special reason, unless to bring about a correspondence with the twelve months of the year—represents the result of continued observation, but its main purpose was to enlarge still further the field of divination.

Babylonians Discovered Astronomical Geometry More than 2000 Years Ago

Babylonian astronomers, writing on cuneiform tablets, used surprisingly sophisticated geometry to calculate the orbit of what they called the White Star — the planet Jupiter — according to Mathieu Ossendrijver of Humboldt University. By comparing a tablet named BM 40054 by the British Museum, and dubbed Text A by Ossendrijver, to the four previously mysterious tablets. “That is a truly astonishing find,” said Ossendrijver, who described the discovery in an article in the journal Science in January 2016. “It’s a figure that describes a graph of velocity against time,” he said. “That is a highly modern concept.”Mathematical calculations on four other tablets show that the Babylonians realized that the area under the curve on such a graph represented the distance traveled and calculating the distance Jupiter traveled in the sky from its appearance to its position 60 days later. Using the technique of splitting a trapezoid into two smaller ones of equal area, they then figured out how long it took Jupiter to travel half that distance. [Source: Kenneth Chang , New York Times, January 28, 2016 ***]

Ossendrijver was able to decipher that the five tablets computed the predictable motion of Jupiter relative to the other planets and the distant stars. “This tablet contains numbers and computations, additions, divisions, multiplications. It doesn’t actually mention Jupiter. It’s a highly abbreviated version of a more complete computation that I already knew from five, six, seven other tablets," he said. [Source: Joel Achenbach, Washington Post, January 28, 2016 |||]

Mari Disk

Joel Achenbach wrote in the Washington Post: “Most strikingly, the methodology for those computations used techniques that resembled the astronomical geometry developed in the 14th century at Oxford's Merton College. The tablets have been authoritatively dated to a period from 350 B.C. to 50 B.C. “But Ossendrijver said nothing in the newly decoded computations suggests that the ancient scientist or scientists who etched the tablets understood that heliocentric model [planets revolving around the sun]. The calculations merely describe Jupiter's motion over time as it appears to speed up and slow down in its journey across the night sky. Those calculations are done in a surprisingly abstract way — the same way the Oxford mathematicians would do them a millennium and a half later.

“It's geometry, which is itself old, but it's applied in a completely new way, not to fields, or something that lives in real space, but to something that exists in completely abstract space," Ossendrijver said. "Anybody who studies physics would be reminded of integral calculus." Which was developed in Europe in 1350, according to historians. “In Babylonia, between 350 and 50 B.C., scholars, or maybe one very clever guy, came up with the idea of drawing graphs of the velocity of a planet against time, and computing the area of this graph — of doing a kind of computation that seems to be thoroughly modern, that is not found until 1350," Ossendrijver said. |||

Kenneth Chang wrote in the New York Times: “When Jupiter first appears in the night sky, it moves at a certain velocity relative to the background stars. Because Jupiter and Earth both constantly move in their orbits, to observers on Earth, Jupiter appears to slow down, and 120 days after it becomes visible, it comes to a standstill and reverses course.” “Dr. Ossendrijver said he did not know the astronomical or astrological motivation for these calculations. It was an abstract concept not known elsewhere at the time. “Ancient Greek astronomers and mathematicians didn’t make plots of something against time,” Dr. Ossendrijver said. He said that perhaps 14th by scholars in England and France perhaps had seen some as yet unknown texts dating to Babylonian times, or they developed the same techniques independently. “It anticipates integral calculus,” Dr. Ossendrijver said. ***

Earliest Description of the Northern Lights — by the Assyrians

The first people to document auroras — known in the Northern Hemisphere as the northern lights — were, surprisingly enough. the Assyrians. A massive solar burst in the early 7th century B.C. and produced auroras that were visible as far south as Mesopotamia. Three cuneiform tablets from Nineveh record this unusual event, documenting a strange “red glow,” “red cloud,” and “red sky.” A study on the findings was published in The Astrophysical Journal Letters in October 2019 and based on descriptions taken from ancient Assyrian tablets housed at the British Museum in London.[Source: Archaeology magazine, January-February 2020]

Candida Moss wrote in the Daily Beast: The descriptions, the lead researcher astrophysicist Hisashi Hayakawa told Livescience, “are quite consistent with the early modern descriptions of auroral display.” The descriptions of this phenomenon were found on three tablets that date to between 679 and 655 B.C. The next earliest reference is a Babylonian text known as the “Astronomical Diaries” which dates to the reign of King Nebuchadnezzar II about a century later on the 12/13 March 567 B.C. And just like the Assyrian tablets, the Babylonian account refers to a “red glow” in the sky. [Source: Candida Moss, Daily Beast, November 3, 2019]

Given that, today, the Northern and Southern lights appear around the earth’s magnetic poles, we might wonder how it is even possible that someone in the ancient Near East (a region roughly equivalent to Iraq-Turkey) could possibly have seen these lights? Indeed, the ethereal glow of the Auroras is the result of collisions between electrons from the magnetosphere (the area controlled by the Earth’s magnetic field) and because the Earth’s magnetic field is in flux, magnetic north was closer to the ancient near east 2500 years ago than it is today. Approximately 10 degrees closer, in fact. The shifts in the magnetic field makes it more likely that the Aurora Borealis would have been visible to ancient Assyrians. The red glow described in the cuneiform tablets may well be the kinds of low-altitude auroras produced by low-energy collisions of electrons and oxygen.

As late as the early modern period, said Hayakawa, it was “not something extremely surprising to see aurorae in the Middle East.” They are recorded in Alexandria, Cairo, and Baghdad in the 19th century. The fact that descriptions of a red sky appear so rarely in astronomical texts suggests that the phenomenon described in the tablets is not simply the kind of vivid red sky we sometimes see at sunset.

Decline of Mesopotamian Astrology and the Rise of Astronomy and Science

Morris Jastrow said: “Despite the elaborate system, however, developed by the Babylonian priests, the decline of astrology sets in toward the close of the Assyrian period. It is significant that in the inscriptions of the rulers of the neo-Babylonian dynasty,—Nabopolassar to Nabon-nedos, 625 to 539 B.C., —we find no direct references to astrological omens. The gods reveal themselves in dreams and by the liver of sacrificial animals, but there are no omens derived from phenomena in the heavens. This may be, of course, accidental, and yet, considering that this period marks the beginning of a noteworthy advance in astronomy, it would rather seem that the rise of genuine astronomical science gave the death-blow to ,the belief in the revelations of stars. The advent of the Persians, who put an end to the neo-Babylonian empire in 539 B.C., was followed, as so frequently happens with the coming of a great conqueror, by an intellectual impulse. In contrast with the Babylonian religion and cult, (so full of survivals from the animistic stage), Zoroastrianism or Mazdeism, brought into Babylonia by the Persian rulers, was rationalistic in the extreme. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911 ]

Astronomy versus Astrology marks the beginning of the conflict between Science and Religion in Babylonia and Assyria, which, as in all subsequent phases of that conflict elsewhere, could have only one outcome,—the triumph of Science. Astrology, we have seen, started out as an expression of the science of the day. Dethroned from that position, it became, in the literal sense of the word, a superstition, a survival of an intellectual phase that had been outgrown. [Source: Morris Jastrow, Lectures more than ten years after publishing his book “Aspects of Religious Belief and Practice in Babylonia and Assyria” 1911 ]

“Strange to say, however, the rise of astronomy and the decline of astrology in Babylonia were coincident with the introduction of astrology into the lands swayed by Greek culture. The two movements are connected. Whereas astronomy began among the Greeks long before their contact with the East, it yet received a strong impulse, as did other sciences, through the new era inaugurated by Alexander the Great, and marked by the meeting of Orient and Occident. Several centuries, however, before the days of Alexander the Greeks had begun to cultivate the study of the heavens, not for purposes of divination but prompted by a scientific spirit as an intellectual discipline that might help them to solve the mysteries of the universe. The tradition recorded by Herodotus that Thales discovered the law of eclipses rests on an uncertain foundation; but, on the other hand, it is certain that by the middle of the fourth century B.C., the Greek astronomers had made great advances in the study of heavenly movements. Nor is there any reason to question that, in return for the impulse that contact with the Orient gave to the Greek mind, the Greeks imparted their scientific view of the universe to the East.

“They became the teachers of the East in astronomy as in medicine and other sciences, and the credit of having discovered the law of the precession of the equinoxes belongs to Hipparchus, the Greek astronomer, who announced this important theory about the year 130 B.C. On the other hand, and in return for improved methods of astronomical calculation, which, it may be assumed, contact with Greek science also gave to the Babylonian astronomers, the Greeks accepted from the Babylonians the names of the constellations of the ecliptic; but in the case of the planets, they substituted for the Babylonian gods the corresponding deities of their own pantheon. More than this, they actually adopted from the Babylonians the system of astrology and grafted it on their own astronomical science. We have the evidence of Vitruvius, and others, to the effect that Berosus the “Chaldean” priest, a contemporary of Alexander the Great, settled in the island of Cos (the home of Hippocrates), and taught astrology to a large number of students who were attracted by the novelty of the subject. Whereas in Babylonia and Assyria we have astrology first and astronomy afterwards, in Greece we have the sequence reversed—astronomy first and astrology afterwards.

Influence of Babylonian Astronomy on Ancient Greek Science

John Burnet wrote in “Early Greek Philosophy”: “The other source from which the Ionians were supposed to have derived their science is Babylonian astronomy. It is certain, of course, that the Babylonians had observed the heavens from an early date. They had planned out the fixed stars, and especially those of the zodiac, in constellations. That is useful for purposes of observational astronomy, but in itself it belongs rather to mythology or folklore. They had distinguished and named the planets and noted their apparent motions. They were well aware of their stations and retrograde movements, and they were familiar with the solstices and equinoxes. They had also noted the occurrence of eclipses with a view to predicting their return for purposes of divination. But we must not exaggerate the antiquity or accuracy of these observations. It was long before the Babylonians had a satisfactory calendar, and they kept the year right only by intercalating a thirteenth month when it seemed desirable. That made a trustworthy chronology impossible, and therefore there were not and could not be any data available for astronomical purposes before the so-called era of Nabonassar (747 B.C.). The oldest astronomical document of a really scientific character which had come to light up to 1907 is dated 523 B.C., in the reign of Cambyses, when Pythagoras had already founded his school at Croton. Moreover, the golden age of Babylonian observational astronomy is now assigned to the period after Alexander the Great, when Babylon was a Hellenistic city. Even then, though great accuracy of observation was attained, and data were accumulated which were of service to the Alexandrian astronomers, there is no evidence that Babylonian astronomy had passed beyond the empirical stage. [Source: John Burnet (1863-1928), “Early Greek Philosophy” London and Edinburgh: A. and C. Black, 1892, 3rd edition, 1920, Evansville University]

“We shall see that Thales probably knew the cycle by means of which the Babylonians tried to predict eclipses; but it would be a mistake to suppose that the pioneers of Greek science had any detailed knowledge of Babylonian observations. The Babylonian names of the planets do not occur earlier than the writings of Plato's old age. We shall find, indeed, that the earliest cosmologists paid no attention to the planets, and it is hard to say what they thought about the fixed stars. That, in itself, shows that they started for themselves, and were quite independent of Babylonian observations, and the recorded observations were only made fully available in Alexandrian times. But, even if the Ionians had known them, their originality would remain. The Babylonians recorded celestial phenomena for astrological purposes, not from any scientific interest. There is no evidence that they attempted to account for what they saw in any but the crudest way. The Greeks, on the other hand, made at least three discoveries of capital importance in the course of two or three generations. In the first place, they discovered that the earth is a sphere and does not rest on anything. In the second place, they discovered the true theory of lunar and solar eclipses; and, in close connection with that, they came to see, in the third place, that the earth is not the center of our system, but revolves round the center like the planets. Not much later, certain Greeks took, at least tentatively, the final step of identifying the center round which the earth and planets revolve with the sun. These discoveries will be discussed in their proper place; they are only mentioned here to show the gulf between Greek astronomy and everything that had preceded it. On the other hand, the Greeks rejected astrology, and it was not till the third century B.C. that it was introduced among them.

“We may sum up all this by saying that the Greeks did not borrow either their philosophy or their science from the East. They did, however, get from Egypt certain rules of mensuration which, when generalized, gave birth to geometry; while from Babylon they learnt that the phenomena of the heavens recur in cycles. This piece of knowledge doubtless had a great deal to do with the rise of science; for to the Greek it suggested further questions such as no Babylonian ever dreamt of.”

Image Sources: Wikimedia Commons

Text Sources: Internet Ancient History Sourcebook: Mesopotamia sourcebooks.fordham.edu , National Geographic, Smithsonian magazine, especially Merle Severy, National Geographic, May 1991 and Marion Steinmann, Smithsonian, December 1988, New York Times, Washington Post, Los Angeles Times, Discover magazine, Times of London, Natural History magazine, Archaeology magazine, The New Yorker, BBC, Encyclopædia Britannica, Metropolitan Museum of Art, Time, Newsweek, Wikipedia, Reuters, Associated Press, The Guardian, AFP, Lonely Planet Guides, “World Religions” edited by Geoffrey Parrinder (Facts on File Publications, New York); “History of Warfare” by John Keegan (Vintage Books); “History of Art” by H.W. Janson Prentice Hall, Englewood Cliffs, N.J.), Compton’s Encyclopedia and various books and other publications.

Last updated July 2024