Photo: Cyril Byrne/The Irish Times
Tomorrow is the winter solstice, the instant where the Sun is at its southernmost point. It is also the shortest day (or longest night, depending how you look at it) of the year. Ancient astronomers knew the significance of this event, and constructed the tomb of Newgrange to mark the arrival of winter solstice. APOD has the story:
Newgrange dates to 5,000 years ago, much older than Stonehenge, but also with accurate alignments to the solstice Sun. In this view from within the burial mound's inner chamber, the first rays of the solstice sunrise are passing through a box constructed above the entrance and shine down an 18 meter long tunnel to illuminate the floor at the foot of a decorated stone. The actual stone itself would have been directly illuminated by the solstice Sun 5,000 years ago. The long time exposure also captures the ghostly figure of a more modern astronomer in motion.
Previously on Neatorama: 10 Most Fascinating Tombs in the World