Happy Solstice!

At 17:47 GMT today, it is officially winter!

That is the time when the poles of the Earth are aligned with the Sun, which is what we call the solstice. The North pole is now pointing away from the Sun (the Winter Solstice, and the shortest day), in the Southern hemisphere, the South pole is pointing towards the Sun (the Summer Solstice).

The image below shows a stacked series of images taken 20 minutes apart throughout the 17th December, 2005 (within just a couple of days of the winter solstice), showing how the Sun moved across the sky during that day, from the South-East to the South-West. A timelapse movie version is also available, showing how low the Sun is in the sky at this time of year.

There are lots of special events to mark the solstice, including a gathering at Stonehenge in Wiltshire (see these photographs: #1, #2, #3, #4). Under the early Julian Calendar, the winter solstice actually occurred on the 25th of December, but because that calendar was not accurate, the solstice slipped to the 21st (the accuracy of the calendar was corrected with the introduction of the Gregorian calendar in 1582).

However, we still traditionally keep the 25th of December as the day for celebration, and Christmas now includes a rich mix of celebrations, including Roman (Saturnalia, and Dies Natalis Solis Invicti, the birthday of the unconquered sun), Nordic Pagan festivals and the Christian celebration of the birth of Christ (see more about the origin of Christmas at this Wikipedia article).

Whichever way you choose to celebrate this time of year, I hope you will enjoy yourselves and have a very happy festive season!