Last month Norfolk was treated to a rare sight, the Aurora Borealis. The spectacular show was due to a coronal mass ejection from the sun. This is a fast moving cloud of charged particles emitted when a sunspot erupts, producing a solar flare. The charged particles interact with atoms of the Earth’s atmospheric gases near the magnetic poles, and the burning gases create a display of ethereal coloured lights – oxygen produces green and yellow lights, nitrogen produces blue, and red and violet can also be seen. The aurora is usually only visible above the north and south magnetic poles, but under the right conditions can be seen at other latitudes. The display in Norfolk is said to have started around 8 pm in the evening and to have lasted for several hours.
The Aurora Borealis is also known as the Northern Lights, and the equivalent in the southern hemisphere, the Aurora Australis, is known as the Southern Lights. Other names for the Northern Lights include Merry Dancers and Lord Derwentwater’s Lights. This last name refers to James Radclyffe, the third Earl of Derwentwater, who was an English Jacobite beheaded for rebellion on 24 February 1716, when the lights were said to be unusually brilliant.
There are many myths associated with the Northern Lights. They take the name Aurora from the Roman goddess of the dawn who flies across the sky every morning to announce the arrival of her brother, Sol, the sun. Her sister is Luna, the moon, and the morning dew is referred to as Aurora’s tears. According to Brewer’s 1870 Dictionary of Phrase and Fable, the lights were ascribed by “northern savages” to the merriment of ghosts, while Finnish legend suggests that the lights are caused by magical fire-foxes whose tails brush the sky, creating sparks. The Saami people of Lapland believed that the lights were the energies of the souls of the departed, or the fire of torches lighting their way to heaven. In Norway they were thought to be the spirits of old maids dancing in the sky, the Vikings called them the bridge to Valhalla, and the Australian aborigines interpreted them as the gods dancing. The lights may also have been the origin of early dragon legends from China and Europe, where they were interpreted as the dragons’ firey breath.
If you missed out this time you may like to use Lancaster University’s AuroraWatch service. Sign up at http://aurorawatch.lancs.ac.uk/alerts and they will alert you by email or Twitter when an aurora is likely to be visible from the UK.