SATELLITE IMAGERY MEASURES OF THE ASTRONOMICALLY ALIGNED MEGALITHS AT NABTA PLAYA

Abstract

The Nabta Playa megalithic complex consists of two types of features: first are large stones, many of them shaped, placed on or in the sediments of an ancient seasonal lake bed that is now hyper-arid second are large sculpted bedrock features underneath the sediments and associated with the surface megaliths(Wendorf et al.1992). The astronomically aligned surface megalithic structures described in field reports(Wendorf and Malville,2001)are identifed in recent georectified 60 cm panchromatic satellite imagery of Nabta Playa,southern Egypt. The satellite images allow refinement, often significant,of the reported locations of the megaliths (Malville et al. i998,and Wendorf and Malville 2001). The report that a primary megalithic alignment was constructed to point to the bright star Sirius, circa 4,820 BC,is reconsidered in light of the satellite data, new field data,radiocarbon, lithostratigraphic and geochronologic data, and the playa sedimentation history Other possible archaeoastronomical interpretations are considered for that alignment, including the three star asterism(of Alnitak, Alnilam,and Mintaka)circa 6,270 BC that is also implicated in the small Nabta Playa 'calendar circle'. Signatures of other possible features apparent in the satellite imagery and a recent field study are also considered. Only a small number of the subsurface bedrock sculptures have been excavated. We recommend the use of ground penetrating imaging methods to illuminate the known but not yet excavated subsurface features. The problem of determining the astronomical intent of the builders of the megalithic structures is approached by considering the complex of features as a whole.