Few natural phenomena have the power to beguile quite like the aurora borealis and no-one ever forgets their first experience of watching what could just be the greatest show on earth.
What’s it Like?
As elusive as they are mysterious, these shape-shifters of the Arctic night sky quickly take on the quality of a fairytale. One moment, the ethereal white or green curtains of light with a streak of violet take on forms that evoke the ancient mythology of the north – a palace of lights, a Sámi fire in the wilderness, the prow of a Viking ship. Then they dissolve into nothing, only to form as if by stealth on a different horizon, dancing across the sky in the shape of sea horse or crescent moon.
There are, of course, an infinite variety of forms, colours and intensities that the aurora can take on. Sometimes they show up in all their glory, a rainbow spectrum of deep blues, indigos and greens. On other occasions, the effect is more subtle, taking on the appearance of an eerie white-grey, transparent cloud shadow that drifts across the sky, refusing to take on recognisable form, then disappearing on the wind against a palette of stars. And there are times when it refuses to show up at all.
‘Aurora is a diva with mood swings,’ is how Knut Hansvold, a native of Tromsø in northern Norway and a veteran northern-lights watcher, explains it. ‘You never know when she’s in a good mood. You have to devote all of your time and attention to her. She expects that and, if you do, she might be tempted. But when she shows up, she is the most unforgettable of beautiful ladies.’
Why does it happen?
The aurora borealis occurs when storms on the sun hurl charged solar particles out into space. When these particles collide with the earth’s atmosphere, they unleash a reaction within the nitrogen and oxygen atoms high above the earth.
That reaction is at once simple and devilishly complicated, depending on your level of scientific understanding. In simple terms, the nucleus of any given atom is surrounded by an orbiting cloud of electrons. When the sun’s particles crash into the atoms, this sends the electrons into higher-energy orbits, away from the atom’s nucleus. When the electrons move back to their usual lower-energy orbits, they release a particle of light known as a photon.
In the case of the aurora, the different colours come from the different gases – particles interacting with oxygen create a yellow or green aurora (although interaction with higher-altitude oxygen can produce all-red shows). Nitrogen is more often associated with blue or purple lights dancing across the sky.
Myths & Legends
The aurora borealis must have been a profoundly unsettling experience in the pre-scientific age and it should come as no real surprise that history is filled with supernatural explanations for the lights. Indeed, the very name ‘aurora’ carries with it the whiff of legend – the word means ‘sunrise’ in Latin, but it also refers to the Roman goddess of dawn.
Later, among traditional peoples, explanations focused on deeply held religious beliefs. Some Inuit believed that the spirits of their ancestors could be discerned in the auroral night sky. In Old Norse mythology, during the time of the Vikings, the aurora represented a fire bridge to the sky built by the gods. Fire featured in later explanations. The southern phenomenon, the aurora australis, was, in one version, believed by Australia’s Aborigines to be bushfires in the spirit world. Back in the north, one Norwegian chronicler explained the phenomenon as either an ocean surrounded by vast fires or the release of energy that turns glaciers fluorescent. Yet another ancient Norse legend held that the lights flickered out from the armour of warlike virgins riding horses across the sky.
A further recurring theme, particularly in medieval Europe, was the belief that the lights were omens or signs from God. The unusual appearance of the aurora on a Virginia battlefield during the American Civil War was interpreted by both sides as a portent of impending victory.
More poetically, one Native American people, the Cree, describe the lights as the ‘Dance of the Spirits’.
Where to see them in Norway
The northern lights can turn up at lower latitudes during years of unusual solar activity. However, most places in Norway north of the Arctic Circle offer the chance to witness the aurora in the night sky from October to March; you’ve a better chance of cloudless skies from December onwards.
The most important element for seeing the aurora borealis, apart from a large slice of luck, is a cloud-free sky – if the cloud cover shows no signs of clearing, you might as well head indoors. Although visitors and residents alike report spectacular light shows in cities such as Tromsø (which is connected to the rest of Norway and further afield by regular flights), another important ingredient for getting the full effect is the absence of artificial or human-produced light. And some experienced aurora-watchers will tell you that, statistically speaking, 6pm to midnight or, even more specifically, from 10pm to 11pm, are the optimum viewing times.
Another important consideration, especially if you plan to photograph the lights, is the backdrop. Seeing the lights surrounded by mountains may mean that you miss half the show – an open horizon (such as the ocean, or the vast plains of the Finnmarksvidda plateau around Kautokeino or Karasjok) is ideal. Open water, particularly a still lake (finding such a lake that’s not frozen in northern Norway can be tricky) can make for some wonderful reflections.
Then again, rules are made to be broken - watching the lights swirl amid the craggy peaks of the Lofoten Islands, or above Tromsø’s Arctic Cathedral or Alta’s Northern Lights Cathedral are the kind of experiences that will live long in the memory.
Useful Resources
UNIS (kho.unis.no/Forecast.htm) Real-time, English-language forecasts from Norwegian sources
Service Aurora (aurora-service.eu/aurora-forecast/) Regularly updated forecasts for Scandinavia
Space Weather (spaceweather.com) Global predictions about upcoming auroras
