Powerful solar wind is blowing from the sun these days, setting the sky ablaze with auroras as far south as London, and forecasters predict that more such displays are on the way, as another solar eruption is set to arrive later Monday (Feb. 27).
Stunned skywatchers took to Twitter in droves to share their photos, with reports of aurora sightings pouring in from Scotland, northern Wales, Ireland and southern England.
Northern Irish photographer Evan Boyce experienced a memorable night of aurora chasing, which, despite being his first polar lights adventure, produced some stunning results.
"I first picked up a camera during the COVID lockdown and have wanted to capture the aurora ever since," Boyce told Space.com in an email. "It's quite difficult living in Northern Ireland, given how far south we are in comparison to where the aurora can normally be viewed."
He added that all his earlier attempts at aurora chasing were ruined by cloudy weather. On Sunday night, Boyce drove to a beach between the towns of Bangor and Donaghadee, a short drive from Northern Ireland's capital Belfast. There he captured an eerie green and red glow above a historical building with a backdrop of a star-studded sky.
"I can't believe how lucky I've been," Boyce said. "Judging by the reaction from other local photographers, the strength & colors last night were a rare event."
Stuart Atkinson, who lives in the popular Lake District natural park in northwestern England, is a much more seasoned astrophotographer than Boyce. A contributor to Space.com's sister magazine All About Space, Atkinson managed to capture a series of infernal red auroras after what he described as a "frustrating aurora-hunt" sabotaged by weather.
"I took the images last night from a place called Shap, probably one of the highest locations in my area and far enough further north of where I live to give me a better view of the aurora than I would have at home," Atkinson told Space.com "Last night conditions were pretty poor at first, almost total cloud, but after an hour or so a big gap appeared and I managed to get a few photos. Very pleased with how they turned out."
He added, however, that the natural colors visible in the sky were much more subdued compared to the photos he produced.
"The long exposure, sensitive sensor and high ISO all enhanced the colors," Atkinson said. "Visually the aurora was pale gray green at the bottom, and pale pink at the top."
Reports of aurora sightings also came from the other side of the Atlantic Ocean. Aside from the traditional aurora photography hotspots in Canada and Alaska, some minor sightings were reported from Ohio and New York state.
The Northern Lights over Stonehenge last night 😲😍❤️💚💙💛 📷 credit by Stonehenge Drone scapes on FB#Aurora #auroraborealis #northernlights #stonehenge #stars #astro #OMG #beautiful pic.twitter.com/YNgROjYPr6February 27, 2023
According to the U.K. space weather forecaster Met Office, the spectacle was a result of two solar physics phenomena occurring at the same time. There is currently a so-called coronal hole opened in the sun's magnetic field, from which streams of solar wind emanate at higher than usual speeds. In addition to that, a coronal mass ejection (CME), a powerful burst of solar plasma from an active region, or sunspot, erupted from the sun on Friday, Feb. 24, and arrived last night.
Solar wind is a stream of charged particles that constantly flows from the sun's upper atmosphere into the surrounding space. These particles interact with particles in Earth's atmosphere, triggering aurora displays. When the flow of the solar wind is low, auroras may only be visible above the polar circles where the planet's magnetic field funnels the particles deeper into Earth's atmosphere. CMEs and fast streams of solar winds from coronal holes, however, can trigger aurora displays much farther away from the poles.
Colors visible in aurora displays are caused by particular reactions between the solar wind particles and chemical compounds present in air.
"Different gases glow a different color," Affelia Wibisono, an astronomer at the Royal Observatory in Greenwich, London, told Space.com in an email. "Oxygen glows green, and blue and purple colors are emitted by nitrogen. If those incoming charged particles are particularly energetic, then high altitude oxygen can also give off a deep red color and nitrogen can glow pink."
Aurora chasers are on standby for tonight as another, even more powerful CME is set to arrive today. The Met Office forecasts a strong G3 geomagnetic storm, which should produce more stunning aurora displays, but could also cause minor problems to satellite operators and power grids at northern latitudes.