
After snow, sleet, and heavy wind all day, the clouds parted for a 2 hour display of spectacular pale green, blue, and purple auroras over the mountains of Reine.
"After snow, sleet, and heavy wind all day, the clouds parted for a 2 hour display of spectacular pale green, blue, and purple auroras over the mountains of Reine," says photographer Matthew Steinberg.
Blue auroras are rare. Auroras are usually green, and sometimes red. Those are the colors produced by oxygen when it is excited by electrons raining down from space. Blue is a sign of nitrogen. Energetic particles striking ionized molecular nitrogen (N2+) at very high altitudes (> 400 km) produces a cold azure glow of the type captured in Steinberg's photo. Usually the blue is faint, but on Feb. 18th it was strangely intense.
Indeed, it could happen. A G1-class geomagnetic storm is underway, and more Arctic auroras are in the offing.
www.spaceweather.com