To those gathering over the centuries at Stonehenge — the imposing prehistoric monument that has dominated Salisbury plain in southwest England for some 4,500 years — it was likely clear how the sun could have informed its design. The central axis of the stone circle was, and still is, aligned with the sunrise at midsummer and sunset at midwinter, the stones dramatically framing the rising and setting sun when days were at their longest and shortest. But do Stonehenge and potentially other megalithic monuments around the world also align with the moon? The idea that Stonehenge was linked in some way to the moon gained ground in the 1960s. However, the concept hadn’t been systematically explored, said Clive Ruggles, professor emeritus of archaeoastronomy in the school of archaeology and ancient history at the University of Leicester. This summer, archaeologists are using a little-known lunar phenomenon that happens every 18.6 years…
