Those lucky enough to see the illumination posted stunning images on social media.
This story originally appeared on Time.com.
Streetlights across much of Iceland’s capital were switched off Wednesday night so its citizens could make the most of the otherworldly glow of the aurora borealis dancing in the sky above them — without the usual interference from light pollution.
Lights in central Reykjavik and several outlying districts went out for about an hour at 10 p.m. local time, and residents were encouraged to turn off lights at home, the Iceland Monitor reported.
While those in Iceland can expect to see the aurora borealis, also known as the northern lights, at any time from September to May, high solar-particle activity combined with clear skies on Wednesday created unusually perfect conditions.
The northern lights are produced when charged particles from the sun hit the earth’s atmosphere at the magnetic North and South Poles. The charged particles interact with the atmosphere, which can be seen as illuminating swathes of light.
Many people posted breathtaking images to social media.
Conditions were equally clear in several other countries, creating waves of aurora-based activity that could be seen in the north of the U.K and U.S.