Babylonian Observations Research Articles

The moon wears a crown: Babylonian reports of earthshine

AbstractObservations of the first visibility of the new moon crescent by ancient Babylonian astronomers often refer to the moon “wearing a crown”. In this article, we undertake a detailed analysis of all Babylonian reports of the observation of the new moon crescent in order to test the common assumption that this phrase refers to the phenomenon of Earthshine. We conclude that the assumption is correct and further explore the observational circumstances that made Earthshine visible to the Babylonian astronomers—and by analogy to any experienced naked‐eye observer. We demonstrate that the most significant factor in whether or not Earthshine is seen is not, as might be expected, the age of the moon but instead the prevailing sky darkness. We also show that the Babylonian observations display a seasonal variation that is consistent with modern observations of and models for the Earth's albedo.

A study of Babylonian planetary theory III. The planet Mercury

In this series of papers I attempt to provide an answer to the question how the Babylonian scholars arrived at their mathematical theory of planetary motion. Papers I and II were devoted to system A theory of the outer planets and of the planet Venus. In this third and last paper I will study system A theory of the planet Mercury. Our knowledge of the Babylonian theory of Mercury is at present based on twelve Ephemerides and seven Procedure Texts. Three computational systems of Mercury are known, all of system A. System A1 is represented by nine Ephemerides covering the years 190 BC to 100 BC and system A2 by two Ephemerides covering the years 310 to 290 BC. System A3 is known from a Procedure Text and from Text M, an Ephemeris of the last evening visibility of Mercury for the years 424 to 403 BC. From an analysis of the Babylonian observations of Mercury preserved in the Astronomical Diaries and Planetary Texts we find: (1) that dates on which Mercury reaches its stationary points are not recorded, (2) that Normal Star observations on or near dates of first and last appearance of Mercury are rare (about once every twenty observations), and (3) that about one out of every seven pairs of first and last appearances is recorded as “omitted” when Mercury remains invisible due to a combination of the low inclination of its orbit to the horizon and the attenuation by atmospheric extinction. To be able to study the way in which the Babylonian scholars constructed their system A models of Mercury from the available observational material I have created a database of synthetic observations by computing the dates and zodiacal longitudes of all first and last appearances and of all stationary points of Mercury in Babylon between 450 and 50 BC. Of the data required for the construction of an ephemeris synodic time intervals Δt can be directly derived from observed dates but zodiacal longitudes and synodic arcs Δλ must be determined in some other way. Because for Mercury positions with respect to Normal Stars can only rarely be determined at its first or last appearance I propose that the Babylonian scholars used the relation Δλ = Δt −3;39,40, which follows from the period relations, to compute synodic arcs of Mercury from the observed synodic time intervals. An additional difficulty in the construction of System A step functions is that most amplitudes are larger than the associated zone lengths so that in the computation of the longitudes of the synodic phases of Mercury quite often two zone boundaries are crossed. This complication makes it difficult to understand how the Babylonian scholars managed to construct System A models for Mercury that fitted the observations so well because it requires an excessive amount of computational effort to find the best possible step function in a complicated trial and error fitting process with four or five free parameters. To circumvent this difficulty I propose that the Babylonian scholars used an alternative more direct method to fit System A-type models to the observational data of Mercury. This alternative method is based on the fact that after three synodic intervals Mercury returns to a position in the sky which is on average only 17.4° less in longitude. Using reduced amplitudes of about 14°–25° but keeping the same zone boundaries, the computation of what I will call 3-synarc system A models of Mercury is significantly simplified. A full ephemeris of a synodic phase of Mercury can then be composed by combining three columns of longitudes computed with 3-synarc step functions, each column starting with a longitude of Mercury one synodic event apart. Confirmation that this method was indeed used by the Babylonian astronomers comes from Text M (BM 36551+), a very early ephemeris of the last appearances in the evening of Mercury from 424 to 403 BC, computed in three columns according to System A3. Based on an analysis of Text M I suggest that around 400 BC the initial approach in system A modelling of Mercury may have been directed towards choosing “nice” sexagesimal numbers for the amplitudes of the system A step functions while in the later final models, dating from around 300 BC onwards, more emphasis was put on selecting numerical values for the amplitudes such that they were related by simple ratios. The fact that different ephemeris periods were used for each of the four synodic phases of Mercury in the later models may be related to the selection of a best fitting set of System A step function amplitudes for each synodic phase.

Babylonian observations of a unique planetary configuration

In this paper, we discuss Babylonian observations of a “massing of the planets” reported in two Astronomical Diaries, BM 32562 and BM 46051. This extremely rare astronomical phenomenon was observed in Babylon between 20 and 30 March 185 BC shortly before sunrise when all five planets were simultaneously visible for about 10 to 15 min close to the horizon in the eastern morning sky. These two observational texts are not only interesting as records of an extremely rare planetary configuration, but also because (1) the observers appear to be confused by the presence of all planets simultaneously and mix them up in their reports, and (2) the two reports of the same observations are so different that we are forced to conclude that they were carried out by two different observers. There is an additional astronomical event which makes this planetary configuration even more unique: the exact conjunction of the planets Mars and Jupiter in the afternoon of 25 March 185 BC. An exact conjunction, where two planets are so close together that they appear as one object in the sky, is also extremely rare. Although this exact conjunction between Mars and Jupiter occurred during the day so that it was not observable, it was correctly predicted by the Babylonian scholars: a remarkable achievement and a nice illustration of their astronomical craftsmanship. Finally, our study clearly exposes one of the limitations of Babylonian naked-eye astronomy. When first appearances of the planets Mercury, Mars and Saturn are expected around the same date, it is nearly impossible to correctly identify them because their expected positions are only approximately known while they have about the same visual magnitude so that they become visible at about the same altitude above the horizon.

Constraining ΔT from Babylonian lunar appulse and occultation observations

We examine in detail 15 Babylonian observations of lunar appulses and occultations made between 80 and 419 BC for the purpose of setting useful limits on Earth's clock error, as quantified by $\Delta$T, the difference between Terrestrial Time and Universal time. Our results are generally in agreement with reconstructions of $\Delta$T using untimed solar eclipse observations from the same period. We suggest a revised version of the simple quadratic fit to $\Delta$T in light of the new results.

On the Babylonian Sighting-Criterion for the Lunar Crescent and its Implications for Egyptian Lunar Data

The aim of the present paper is to establish a lower boundary condition of a possible successful sighting of the lunar crescent based on Babylonian predictions and observations. This means that all Egyptian chronological options showing deviations in positive direction with visibilities below this boundary condition will be dismissed as impossible. Although a theoretical limit of 10° for the visibility criterion, i.e. a minimum lagtime between sunset and moonset of 40 minutes, is mentioned in text TU 11, the Babylonian Astronomical Normal Star Almanacs contain several predictions for first or last visibility with values smaller than 10° and the Astronomical Diaries a few such observations. Thus, a value of 10° for the lagtime is an inappropriate lower boundary condition which cannot be used as knock-out criterion for Egyptian chronological options based on lunar data.

Babylonian Observations of Venus: Arcus Visionis, Atmospheric Extinction and Observational Practice

1. INTRODUCTIONIn this paper analyse Babylonian observations of Venus from the second half of the first millennium b.c. to derive physical parameters determine its first and appearance as morning and/or evening star. The new feature in my approach is the use of a physical model for the visibility of Venus in a twilight atmosphere. Moreover, in this study make use of the most recent editions of the Babylonian observational material. The results provide a major advance in understanding the visibility phases of Venus compared to earlier attempts based on the use of the concept of the arcus visionis. ' The method used here has been applied before to analyse Babylonian observations of Saturn in the sixth and the seventh centuries b.c., of stars in the thirteenth century b.c., and of Venus in the seventeenth century b.c.22. THE OBSERVATIONSThe observational material analysed in this paper consists of all Babylonian records of first appearance and appearance of Venus in the Astronomical diaries and related texts from Babylonia, vols i-iii, ? and vi.3 This body of observational texts (henceforth referred to as Diaries and related texts) contains a large - although quite fragmentary - body of naked-eye astronomical observations of the Moon and the planets covering a period of many centuries (650-50 b.c.), and thereby form a unique database for the study of the astronomical practice in Babylon during the second half of the first millennium b.c.Among the observational material in the Diaries and related texts, the first appearances and appearances of the planets take a prominent place. In total the Diaries and related texts contain about 180 records of the first and appearance of Venus. These observations are scattered over the six centuries b.c., and due to the arbitrary nature of the preservation process they form a random selection of all first and appearances of Venus over period. Since one of the purposes of this paper is to study the effects of the variable atmosphere made an effort to select only 'bona fide' observations. This is not a trivial matter because the texts are often damaged and some dates are apparently estimated or computed rather than observed. The observations have discarded fall in several categories:* those with uncertain dates due to omissions or damaged passages in the text;* those with qualifications around, possible, expected;* those where the observer indicated no observations were carried out by recording clouds (DIR) or stating I did not watch (NU PAP); and* those given in the monthly summaries at the end of the month, because in cases where it can be verified these often turn out to be the expected 'ideal' dates rather than actually observed dates.The total number of observational records retained amounts to 92 observations (about 50% of all preserved records) over the period 525-80 b.c., and may be considered as a randomly selected sample comprising 8% of all first and appearances of Venus over period.Throughout the Diaries and related texts the Babylonian term SU (setting) has been translated as last Based on an analysis of Venus observations available at the time, Huber et al.4 pointed out the data make more sense if SU is translated as disappearance, consistent with its actual meaning. This is in agreement with the fact in the earliest set of Venus observations from the time of Ammisaduqa (seventeenth century b.c.) the verb it-bal is used which means disappeared.5 In a footnote on page X of the Diaries and related texts, vol. vi, the editors confess to having become convinced that by SU the texts refer to the first day when a planet could not be seen anymore but in the translation they would stick to last appearance for reasons of consistency. In the analysis below take SU to refer to the disappearance of Venus, which falls one day later than the date of appearance. …

Book Review: The Chronology of Old Babylon, Die Venustafeln des Ammī-⋅aduqa und ihre Bedeutung für die astronomische Datierung der altbabylonischen Zeit

THE CHRONOLOGY OF OLD BABYLON Die Venustafeln des Ammi-saduqa und ihre Bedeutung fur die astronomische Datierung der altbabylonischen Zeit. Joachim Mebert (Archiv fur Orientforschung Beiheft, xxxi; Berger & Sohne, Horn, 2010). Pp. 179. 38 (paperback). ISBN 3-900345-10-4.In 1912 F. X. Kugler discovered among omens on sixty-third tablet of Babylonian celestial omen series Enuma Anu Enlil a reference to Year of Golden Throne which he identified with eighth year of Old Babylonian king Ammi-saduqa. Tablet 63 of Enuma Anu Enlil contains a series of omens referring to dates of Venus's first visibility and first invisibility in morning and evening. Kugler suggested that, contrary to other tablets of Enuma Anu Enlil which contain pure omens, tablet 63 contains reports of observations which had been codified as omens. If this suggestion is correct, then Venus data on Enuma Anu Enlil tablet 63 (commonly referred to as the Venus Tablet of Ammi-saduqa) potentially provides means to establish date of reign of Ammi-saduqa and hence to provide a fixed point to pin floating, relative chronology of early second millennium b.c. known from king lists and other historical documents.Many attempts to date Venus Tablet of Ammi-saduqa have been made in hundred years since Kugler' s discovery. By middle of twentieth century, three possible chronologies had emerged: a high chronology in which Ammi-saduqa year 1 = -1710, a middle chronology with Ammi-saduqa year 1 = -1645, and a low chronology with Ammi-saduqa year 1 = -1581. Most Assyriologists and historians of ancient Near East have adopted middle chronology, but on no other grounds than that it is a convenient compromise and appears in all standard reference works. In recent years, several scientifically-trained scholars have argued in favour of other chronologies: P. J. Huber has made a forceful case for long chronology by combining evidence from Venus Tablet with eclipse omens from Enuma Anu Enlil tablets 20 and 21 which he believes refer to specific observations as well as month-length data taken from economic documents.1 V. G. Gurzadyan in a much criticized analysis has argued for a super-short chronology with Ammi-saduqa year 1 = -1549. 2 And most recently, T de Jong and V Foertmeyer have argued for Ammisaduqa year 1 = -1637 on basis of a possible connection with eruption of volcano on Thera.3The book under review presents a new and detailed study of Venus Tablet of Ammi-saduqa and its use in determining Old Babylonian chronology. Mebert begins by discussing Venus Tablet itself. It has long been recognized that tablet as it may be reconstructed from preserved copies is corrupt in various ways. Mebert provides a useful study of structure of tablet in order to extract a subset of omens which he believes are reliable. In order to investigate dates of Venus's visibility phenomena found in these omens, Mebert first investigates Late Babylonian observations of Venus in order to establish values for arcus visionis of phenomena of Venus for Babylon. He then uses these values to calculate dates of Venus's visibility during early second millennium b.c. which can then be compared with dates extracted from Venus Tablet. Next, Mebert compares preserved mo nth -length data from Old Babylonian period with calculated month lengths. By combining results from these two types of evidence, he concludes that most likely date for first year of Ammi-saduqa is -1573. Finally, Mebert investigates other evidence - most of it historical rather than astronomical - to see whether there are any contradictions with his proposed chronology and to provide supporting evidence of his proposed chronological equation. …

A Study of Babylonian Observations Involving the Zodiac

A Study of Babylonian Observations Involving the Zodiac

Low latitude auroras prior to 1200 C.E. and Ezekiel’s vision

In another paper in this volume the auroral events of August 28 and September 2, 1859 have been discussed in the context of other events from that time to the present. Elsewhere, Siscoe, Silverman and Siebert have presented persuasive arguments for the proposition that the first chapter of the Biblical book of Ezekiel was a description of an aurora. The present paper discusses a number of low latitude auroras beginning with an unusually active period around 1100 C.E., proceeding through the period of the beginning of the Common Era, to the time of Ezekiel and Assyrian and Babylonian observations.

A Study of Babylonian Observations of Planets Near Normal Stars

The present paper is an attempt to describe the observational practices behind a large and homogeneous body of Babylonian observation reports involving planets and certain bright stars near the ecliptic (“Normal Stars”). The reports in question are the only precise positional observations of planets in the Babylonian texts, and while we do not know their original purpose, they may have had a part in the development of predictive models for planetary phenomena in the second half of the first millennium B.C. The paper is organized according to the following topics: (I) Sections 1–3 review the format of the observations and the texts in which they are found; (II) Sections 4–6 discuss the composition of the Normal Star list; (III) Sections 7–8 concern the orientation of the reported celestial directions from star to planet; (IV) Sect. 9 concerns the relationship between the reported distances and the actual angular distances between planet and star; and (V) Sect. 10 discusses the reports of planetary stations, which are the most common reports giving precise locations of planets when they are not near their closest approach to stars, and draws some brief general conclusions about the utility of the Babylonian observations for estimating planetary longitudes and calibrating models in antiquity.

A Likely Source of an Observation Report in Ptolemy's Almagest

In a recently published volume of Greek papyri from Oxyrhynchus (mod. Bahnasa, Egypt) containing astronomical texts, tables, and horoscopes, I gave pride of place to a remarkable fragment of a theoretical work on planetary theory that, as I there remarked, is "nearer in genre to Ptolemy's Almagest than any hitherto known."1 The text, published under the number P. Oxy. LXI 4133, contains the report of an observation of Jupiter's position in A.D. 104/105, and refers also to another observation of Jupiter made 344 years earlier, the report of which was in the lost part of the text preceding the extant portion. I gave reasons in my commentary for tentatively identifying the author of the treatise as Menelaus of Alexandria, and for identifying the earlier observer more confidently with an anonymous observer of Jupiter cited by Ptolemy in the Almagest. Only more recently did I realize that a rather obvious corollary of my analysis of the papyrus is that the treatise from which it comes was very likely Ptolemy's immediate source for that Jupiter observation. The planetary observations that Ptolemy utilizes fall chronologically into two widely separated groups: (a) observations from his own time (specifically A.D. 127-141) by himself and by someone named Theon; and (b) observations from the third century B.C. by Timocharis, by unnamed Hellenistic observers using a special calendar "according to Dionysius," and by anonymous Babylonian observers. In general it may be said that Ptolemy only uses observations from before his time when he wishes to establish longterm properties of his planetary models (his practice is different in his lunar theory). The older planetary observations can be grouped as follows: Mercury: six Dionysian observations from 265-257 B.C. (two of them are only four days apart), and two Babylonian observations from 245 and 237 B.C. Venus: two observations, four days apart, by Timocharis in 272 B.C. Mars: one Dionysian observation, 272 B.C. Jupiter: one Dionysian observation, 241 B.C. Saturn: one Babylonian observation, 229 B.C. For each planet, Ptolemy uses one old observation together with one from his own time to establish accurate mean motions. His procedure makes no special demands on the

Did Conon of Samos Transmit Babylonian Observations?

Previous articleNext article No AccessNotes and CorrespondenceDid Conon of Samos Transmit Babylonian Observations?Gerald L. GeisonGerald L. Geison Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Isis Volume 58, Number 3Autumn, 1967 Publication of the History of Science Society Article DOIhttps://doi.org/10.1086/350273 Views: 4Total views on this site Citations: 1Citations are reported from Crossref Copyright 1968 History of Science Society, Inc.PDF download Crossref reports the following articles citing this article:Eileen Reeves And Now You Don’t, I Tatti Studies in the Italian Renaissance 24, no.11 (Jul 2021): 191–216.https://doi.org/10.1086/713501

The " Arcus Visionis " of the Planets in the Babylonian Observations

The " Arcus Visionis " of the Planets in the Babylonian Observations