The Crossover of the Sun and the Moon

A novel astronomical phenomenon, termed 'crossover,' has been identified where the rise positions of the sun and full moon intersect around equinoxes. This discovery challenges conventional interpretations of megalithic alignments, suggesting that prehistoric cultures may have tracked non-extreme lunar events like equinoctial full moons (EFMs) rather than just solstices or lunar standstills. The study employed ephemeris simulations to analyze declination and chronological distributions for all lunar phases, focusing on full and dark/crescent moons due to their ethnographic significance. Preliminary case studies from Portugal's megalithic enclosures revealed alignments previously misattributed to sunrise, now linked to EFMs. This research proposes an alternative interpretation for minor lunar standstill alignments, offering new avenues for archaeoastronomers and ethnographers.

Silva, F., & Pimenta, F. (2012). The Crossover of the Sun and the Moon. Journal for the History of Astronomy, 43(2), 191–208. https://doi.org/10.1177/002182861204300204