A rare and spectacular appearance of the northern lights over Scotland and northern England has amazed onlookers.
The ethereal green glow of the aureroa borealis appeared as far south as Northumberland and Cleveland. Experts say that at most the lights are only seen this far south every eleven years.
The stargazers' unusual sightings of the beautiful arcs of turquoise light were down to a solar storm, as flares on the sun's surface caused high energy particles to erupt into space at around 5 million mph.
Twenty four hours later the speeding particles interact with the Earth's atmosphere, where they are trapped by magnetic fields around the planet.
When these gas particles collide they create rainbow ribbons of light, which explode across our skies. The colours of the lights depend on the types of gas particles involved in the collisions.
Aurora comes from the name of the Roman goddess of dawn, while Borealis comes from the Greek name for the north wind, Boreas, by Pierre Gassendi in 1621.
(Photos of some of the best auroras of 2011 can be found below.)