SHAPESHIFTER – KNOWLEDGE OF THE MOON IN GRAECO-ROMAN EGYPT VICTORIA ALTMANN-WENDLING (MUNICH) Introduction Apart from the sun, the moon is the largest and brightest celestial phenomenon as seen from earth. Furthermore, in pre-industrial societies without electric lighting the shifting intensity of nocturnal illumination by the moon played a significantly larger role than today. Hence, it is not astonishing that people used to reflect on the causes and effects of its shift in shape and other associat- ed phenomena. Besides the day-and-night-cycle, the moon’s phases are clearly the most evident means of chronological orientation and therefore lunar-based calendrical systems are quite universal.1 This paper will present the practical application of the lunar phases to the calendar, the regulation of religious festivals, and the temporal organisation of the priests’ services. These indirect pieces of evidence will be further elaborat- ed by Demotic and Greek papyri that contain computations of the moon’s movement and phases. Another topic is the role of the moon in astrology, i.e. how visual phenomena (like eclipses), lunar phases or positions of the moon in the zodiac were used to predict the future. Furthermore, I will also show how the moon and the astronomical phenomena related to it were integrated into the religious imagery and symbolism of ancient Egypt. Since the sources derive mainly from the Graeco-Roman period, during which Egypt was characterised by its multicultural society with increasing contacts to the rest of the Mediter- 1 Cf. NILSSON, 1920, pp. 4f., 15f., 147-239. 213 Victoria Altmann-Wendling ranean and Near Eastern world, reflections on possible exchange, transfer or adoption of knowledge are possible. “Scientific” Knowledge I: Calendars, Accounts, and Astronomers Initially, knowledge about the moon in ancient Egypt was acquired through careful observance of the heavenly body. That this “finding” of knowledge took place can be deduced from several facts. First of all, the Egyptian month consisting of thirty days, which suggests that lunation was the basis of the division of time: thirty is the average length of the synodic month with about 29.53 days, the time span the moon takes to gain the same visual appearance again. Nevertheless, the solar, so-called Civil Calendar of 365 days dominates over a sometimes-presumed original lunar calendar back as far as the earliest written records. The existence of a lunar calendar is in any case much debat- ed.2 However, there is no doubt that the moon played an important role in the division of time. For example, days within the lunar cycle are sometimes given in historical inscriptions alongside solar-calendar dates.3 Thus, even if there is little evidence for the existence of a lunar calendar in parallel to the civil calendar, there is at least evidence that lunar cycles were counted in some form, which indicates that the constant observation of the moon’s phases must have been carried out. Further evidence of lunar observation can be deduced from the fact that several festivals and rituals follow lunar phases,4 including crucial stages such as new moon, first crescent visibility, and full moon. However, the sixth lunar day, which has no obvious astronomical significance, played an important role 2 Discussed e. g. by LEITZ, 1989, pp. 54-57; LUFT, 1992; DEPUYDT, 1997; LEITZ, 2000, pp. 77f.; NOLAN, 2003; SPALINGER, 2004; BELMONTE, 2009; – On the civil calendar, see most recently GAUTSCHY, 2011; RAMCKE, 2014. 3 Their correlation forms the basis for the absolute chronology of Egyptian history in modern Egyptological research (on these double dates cf. PARKER, 1950, pp. 17- 23; LEITZ, 1989, pp. 80-89 [with references]; DEPUYDT, 1997, pp. 177-215; DERSTINE, 2016). 4 A complete list can be found in GRIMM, 1994, pp. 124f., 419-441; BURKARD, 1995, pp. 96-110. 214 Shapeshifter – Knowledge of the Moon in Graeco-Roman Egypt in numerous rituals.5 All of them were most probably annual “high feasts” rather than monthly events, because specific solar months are given in calendar lists: While a specific period of time in the civil calendar was fixed, the exact date of the beginning of the festival was determined by the lunar phase; this is comparable to the Christian Easter date.6 The New Moon and Behedet Feast was a particularly famous feast occurring in the month Epiphi (III. šmw). It celebrated the arrival of Hathor of Dendera in the temple of Horus of Edfu and their joint journey to the local necropolis.7 Its duration of fifteen days is evidently oriented towards the lunar cycle, as this represents the time span from new moon to full moon, on which the climax of the festival took place, probably with special processions that reproduce the constellation of sun and moon on that day.8 However, the term “give appearance to (the god) Min every new moon (sḫʽj(.t) Mnw n psḏn.tyw nb)” that is preserved in a festival list in the Temple of Kom Ombo suggests that there were also monthly festivals.9 Further evidence for this is provided by practices associated with the day of the new moon, on which the moon remained invisible and was therefore thought to be in an endangered state and needed to be secured by rituals against its enemies.10 From the time of the Middle Kingdom onward, the lunar calendar also determined and regulated priestly service.11 The priests were organised in four, later five, so-called phylai (sg. phyle, literally “tribes”, äg. sȝ), each phyle being on duty in the temple for one month. Service was to begin on the second lunar day (ȝbd), i.e. the first day the crescent is visible. From the dates given in wheat receipts from the Roman village of Soknopaiou Nesos, the length of the priests’ service could be calculated.12 The services lasted twenty-nine or thirty days, pointing to a connection with the astronomical lunar month and not with average month lengths or months of the solar calendar. By calculating the 5 The most fundamental work is JUNKER, 1910. Further examination of the date can be found in my doctoral thesis on the moon in Graeco-Roman Egypt (ALTMANN- WENDLING, 2018, pp. 833-843). 6 Cf. RICHARDS, 1998, pp. 345-378. 7 See NAGEL, 2014. 8 ALTMANN-WENDLING, 2017, pp. 426-435. 9 GRIMM, 1994, pp. 124f.; BURKARD, 1995, pp. 108f. 10 Concerning the “Book of the New Moon Festival” see most recently VUILLEUMIER, 2016, pp. 176-221; another new-moon ritual that comprises the ritual destruction of the enemies is studied by LEITZ, 2012, pp. 127-129. 11 DEPUYDT, 1997, pp. 147-151; BENNETT, 2008. 12 LIPPERT, 2009. 215 Victoria Altmann-Wendling actual lunar phase that prevailed on the beginning of the service, Sandra L. Lippert has been able to show that these regulations were based on the old Egyptian calendar and did not draw on the Alexandrian calendar that was introduced after the Roman conquest, and which inserts a leap day every fourth year.13 Furthermore, the comparison between the beginning of each phyle and the computed lunar phase revealed that one half gives a date for the re- appearance of the moon that is one or two days too late.14 Because the beginning of the month is determined by the observation of the old crescent, this means that the priests would have announced the last crescent on a day where there definitively was none.15 Therefore, according to Lippert, the new crescent was probably not observed, but calculated. Unfortunately, no calculation table is known yet which fits into the observed pattern.16 The Egyptian lunar month starts with new moon, i.e. the phase of invisibili- ty.17 During this time span, the moon stands between the sun and the earth and is therefore not illuminated by sunlight as seen from earth. To determine the exact day when the moon disappeared, the thin crescent had to be closely watched. Prior to the use of computed tables in the Graeco-Roman period, the thin crescent had to be closely watched in order to determine the exact day when the moon disappeared.18 Because the observation of a celestial body near to the horizon is very difficult due to atmospheric disturbances, one has to factor in a certain amount of inaccuracy,19 although in general, the observation conditions were probably better than today.20 The astronomical observation was carried out by priests, the earliest record dating to the Old Kingdom (the first half of the third millennium BCE) concerning a priest called Tjenti, who bears the title “Overseer of the secret of 13 IBID., pp. 186f. 14 IBID., p. 188. 15 IBID. Conversely, this might indicate that the start of the period of priestly service was determined by observation of the new crescent, not by awaiting the day after new moon. If this was the case, the faint new light could easily have been missed and the phyle accordingly started one or even two days delayed. 16 IBID., pp. 193f., see below. 17 The same starting point applies to modern astronomy. 18 See below. 19 WELLS, 2002; DOGGETT/SCHAEFER, 1994; SPALINGER, 2002; BENNETT, 2008, pp. 525-554; GAUTSCHY, 2011, pp. 4f. 20 GAUTSCHY, 2011, p. 14; p. 130; RAMCKE, 2014, p. 323 with notes 30 and 35. 216 Shapeshifter – Knowledge of the Moon in Graeco-Roman Egypt the sky, who sees the secret of the sky (ḥry-sšȝ n p.t mȝȝ štȝ n p.t)”.21 Other possible verbs and designations for stargazing from the Old Kingdom to the Graeco-Roman period are sbȝy/wnw.ty,22 wnwn,23 and perhaps wr mȝ.w, “Greatest of the Seers”, the name of the high priest of Heliopolis, the important religious centre that was known for its solar cult, but where important obser- vations of other celestial phenomena also took place.24 However, the most important and best-known sacerdotal title associated with astronomical observation is wnw.ty (from the Middle Kingdom on) resp.