Fri, 16 Nov 2012 12:26 CST
Auroras are usually green, and sometimes purple, but seldom do sky watchers see much red. The geomagnetic storm of Nov. 13/14 was different. It produced auroras with a distinctly rosy hue. David E. Cartier, Sr. photographed the phenomenon near Marsh Lake, about 40 km east of Whitehorse in Canada's Yukon Territory:
© David E. Cartier, Sr
"I was amazed by the deep scarlet color, which was immediately recognizable to the unaided eye," says Cartier. Similar splashes of candy-cane red were spotted over Wisconsin
The apparition might be related to rare all-red auroras
sometimes seen during intense geomagnetic storms. They occur some 300 to 500 km above Earth's surface and are not yet fully understood. Some researchers believe the red lights are linked to a large influx of low-energy electrons. When such electrons recombine with oxygen ions in the upper atmosphere, red photons are emitted. At present, space weather forecasters cannot predict when this will occur.
Could more reds be in the offing? NOAA estimates a 30% to 35% chance of polar geoagnetic storms on Nov. 16th and 17th. Sky watchers seeing red should submit their images here