A team of astronomers from the UK is exploring what might be described as the first astronomical observing tool, potentially used by humans around 4,000 BC. The view towards the east from the Carregal do Sal megalithic cluster, at dawn at the end of April around 4,000 BC, as reconstructed using a Digital Elevation Model and Stellarium. Aldebaran, the last star to rise before the Sun, is rising directly above Serra da Estrela, the ‘mountain range...
