Five things you need to know about today's winter solstice

Today marks the winter solstice - the shortest day in the northern hemisphere.
People gather at Stonehenge in Wiltshire to witness the sunrise on the shortest day of the year.  Pic: PA.People gather at Stonehenge in Wiltshire to witness the sunrise on the shortest day of the year.  Pic: PA.
People gather at Stonehenge in Wiltshire to witness the sunrise on the shortest day of the year. Pic: PA.

Here are five facts about the winter solstice: