ARA·PACIS·AVGVSTAE: An Astro-Archaeological Analysis (Abstract)

Author: Vance Tiede Title: ARA·PACIS·AVGVSTAE: An Astro-Archaeological Analysis

Date: 13 April 2015

Background. The Ara Pacis Augustae (Altar of the Augustan Peace, Rome, Italy, 13-9 BC) is examined as a shrine of light consistent with the astro-orientation principles of Roman architect Vitruvius (c.15 BC, IV:v:1, IV:ix:i). Italian archaeologists excavated (1937/8) the altar some 10 meters under the Via in Lucina, 16 and reassembled it (rotated 75º counter-clockwise from the original) 455 meters NW along the Tiber River (Moretti 1947, 6; Andersen 2003, 5). While la bella figura of its polychrome marble sculpture (Kleiner 1992, 90-99; Foresta 2011) is displayed at the Museo dell’Ara Pacis, until now, the secret of its astro-orientation has remained encoded on a paper site plan. Data. Computer programs “Stonehenge” (Hawkins 1983, 328-330) and “Starry Night Pro Plus” calculated the horizon declination (+11.3º decl.) of the altar’s original North-East facing with the following input data from the site plan by Guglielmo Gatti c.1938 (Stampini 1970, Fig. 2, p. 36) and Google Earth: True Azimuth ≈ 75º; Latitude/Longitude = 41° 54’ 10.47” N/12° 28’ 44.60” E; Elevation ≈ 10 meters ASL; and Horizon Altitude ≈ +1.1º. The Ara Pacis Augustae was dedicated in 9 BC (Res Gestae Divi Augusti, 12.2). Results. The axis of the Ara Pacis Augustae twin enclosure entrances was originally oriented SW-NE to the first gleam of the rising Sun (+11.0º decl.) at dawn on 21 April 9 BC. Analysis & Conclusion. The iconography of the Ara Pacis supports the interpretation that the April 21st sunrise orientation was both intentional and symbolically important. The seated woman (Galinsky 1992), bull and sheep frieze above the tetra-gammadion Μαίανδρος correspond to the heliacal rise of the planet Venus as Morning Star with zodiac constellations Aries and Taurus on the horizon for the festival of Par ilia (Pales, goddess of shepherds) on 21 April 9 BC, i.e., the anniversary of the founding of Rome in 1 a.u.c. (753 BC) according to the Roman historian Marcus Terentius Varro. Moreover, Hannah & Magli 2011 report another solar-calendric orientation for April 21st of politico-religious importance, i.e., the Pantheon’s (Hadrian, c.125 AD) oculus-to-entrance solarnoon/meridian transit alignment. Therefore, a virtual digital 3D animation modeling Roman astro-architectural principles linking the Pax Augusta and Dies Natalis Urbis Romae should be exhibited at the Museo dell’Ara Pacis.

Perspective Drawing of the Reconstructed Ara Pacis (G. Gatti) (Moretti 1947, 17) References: Andersen, Wayne 2003 The Ara Pacis of Augustus and Mussolini, Boston: Editions Fabriart. Foresta, Simone 2011 “La policromia dell’Ara Pacis e I colori del Campo Marzio settentrionale,” https://www.academia.edu/945654/La_policromia_dell_Ara_Pacis_e_i_colori_del_Campo_Marzio_settentrionale Galinsky, Karl 1992 “Venus, Polysemy, and the Ara Pacis Augustae,” American Journal of Archaeology 96:457-475 Hannah, Robert and Giulio Magli 2011 “The Role of the Sun in the Pantheon’s Design & Meaning,” Numen 58:4, 486-513. Hawkins, Gerald S. 1983 Mindsteps to the Cosmos, New York: Harper & Row. Kleiner, Diana E. E. 1992 Roman Sculpture, New Haven: Yale University Press. Moretti, Giuseppe 1947 L’Ara Pacis Augustae, Rome: Istituto Poligrafico dello Stato. Stampini, Pino 1970 “Ara Pacis Augustae,” Dibattiti Rotariani, III:5-6, Roma. Vitruvius c. 15 BC De Architectura Libri Decem (M.H. Morgan, trans.), New York: Dover Press, 1960.