Scottish archaeologists have discovered the world’s oldest known lunar calendar–a series of 12 large, especially shaped pits, around 10,000 years old, that were designed to mimic the various phases of the moon. The pits align perfectly on the midwinter solstice in a way that would have helped the hunter gathers of Mesolithic Britain keep accurate track of the passage of the seasons and the lunar cycle. Thisis older than Stonehenge, which was built sometime between 3000 BC and 2000 BC. These pits pre-date all other calendars so far discovered, but are surprisingly sophisticated, designed so that changes can be made periodically to keep up with the precession of the equinox. Considering their age, this is an amazing and unexpected more