WEST IBERIAN MEGALITHIC TOMBS AND THE “LUNAR SEASON POINTER”

Abstract

Recent investigations of Danish and Swedish passage graves and their orientation patterns show a dominance of orientation directions which can be explained primarily in relation to full moonrises during the summer period. Both the Danish and Swedish passage graves tend to form clusters. Each cluster has a very similar orientation pattern, and this calls for an astronomical explanation. About 200 Portuguese and Spanish megalithic tombs seem to have similar orientation patterns to the Scandinavian ones; these will be the subject of further studies. A group of megalithic tombs located in West Iberia in central Alentejo and the surrounding area have been chosen for a statistical test case using the same model used for the Scandinavian passage tombs. The test model is based on 1) the Equinoctial Full Moons (EFMs), i.e., the “spring full moon” and the “autumn full moon”, 2) the first and last summer full moons (defined as the second full moons in this paper) and 3) the southernmost full moon. These are used in the hypothesis for the test case. The model fits 99% of the observations and the test results show a high statistical probability factor p (p = 0.56) when the observed distribution is matched with the model, meaning that the model distribution and the observed distribution likely have the same origin. The comparison between the main body of the observations (98%) and the model is interesting because the probability factor reaches the value of 0.86, which supports the null hypothesis.