The Northern Lights, or aurora borealis, have been unusually visible all across Europe in recent days, with people far beyond the lights’ usual Arctic Circle haunts registering astonishment and photographs on social media, proving they were able to see the phenomenon in skies above their countries. But, scientists note, the occurrence could be just the start of something even more spectacular.
Torrent of particles
From the UK and Ireland to Germany, and from The Netherlands to Bulgaria to southern Italy and Greece, reports of extraordinary sights in the heavens have come in, indicating that a large solar eruption observed by scientists on Friday 4 November had sent a torrent of charged particles towards Earth, causing the aurora’s increased visibility.
Essentially, a huge solar geomagnetic windstorm created by a “Coronal Mass Ejection (CME) – an expulsion of plasma and magnetic field from the outermost layer of the sun’s atmosphere” as Euronews phrased it, can cause the light’s usual band of activity or “annulus” to expand.
“Nature’s fireworks”
In the UK, the appearance of the lights coincided with an annual holiday called Guy Fawkes Night or Fireworks Night, in which the country commemorates a plot to blow up parliament with torchlit parades, fireworks and burning edifices. Inevitable comparisons between noisy manmade firework displays and “nature’s fireworks” soon came rolling in. Elsewhere people made connections with Halloween, All Saints’ Day, or Day of the Dead, as highlight of the autumnal season for many is variously known.
Also spotted, and even rarer than the lights themselves, a phenomenon named “Steve” which scientists have known about for years but are yet to fully explain.
“Steve”
“Steve”, as the BBC explains, is a “thin purple ribbon of light” seen with the Northern Lights, but not technically a part of them. The column in the sky is thought to be “a fast-moving stream of extremely hot particles called a subauroral ion drift, or SAID”, but its causes are not completely understood.
The funny and down-to-Earth human name for the mystery has been post-rationalised as an acronym for “Strong Thermal Emission Velocity Enhancement” but is thought to have been inspired originally by a mysterious film “character” in “Over the Hedge” – to make him seem less frightening.
The start of solar maximum?
For those who missed out on the sightings, patience might be rewarded more than a visit to the Arctic Circle. Scientists are predicting that 2024 will be a bumper year for aurora borealis enthusiasts. Between January and October the sun’s 11-year activity cyle is forecast to reach its “solar maximum”, with the peak expected to create large displays of the aurora much further south than usual after a weak performance last time in 2014. The events of recent days could therefore be just the start of stirring things to come.
