Ghostly Glow
Photograph courtesy Pavel Kantsurov
Curtains of auroras shimmer over the snow covered forests of Norilsk, Russia, on January 22.
Although auroras are most common closer to the Poles, strong geomagnetic storms can trigger the light shows in lower latitudes. (See aurora pictures: "Rare Northern Lights Seen in U.S. South.")
For instance, during the biggest solar storm on record—the 1859 Carrington Event—northern lights were reported as far south as Cuba and Hawaii, while southern lights were seen as far north as Santiago, Chile.
Published January 25, 2012
Green Lantern
Photograph by Thilo Bubek
Bright green auroras light up the night sky in a picture taken near Tromsø, Norway, on January 21.
The colors of auroras depend on the types of gases in Earth's atmosphere being affected by a solar storm. In most cases, auroral lights come from oxygen being "excited"—given extra electrical energy—during the collisions of gas atoms with solar particles. The charged-up oxygen releases the extra energy as green light.
(Also see "Photos: Multicolored Auroras Sparked by Double Sun Blast" [August 2011].)
Published January 25, 2012
National Geographic
Comments