In this Sept. 3, 2006 file photo, a spectator watches the aurora borealis rise above the Alaska Range, in Denali National Park, Alaska. On Thursday, July 24, 2008, NASA released findings that indicate magnetic explosions about one-third of the way to the moon cause the northern lights, or aurora borealis, to burst in spectacular shapes and colors, and dance across the sky.
(AP Photo/M. Scott Moon, File)

Source:
http://news.yahoo.com/nphotos/NASA-File/photo//080724/480/c2c103d412f84f37abdb7aca0b2f0606//s:/ap/20080724/ap_on_sc/sci_northern_lights;_ylt=As12gkO6ebu.yKZcjHehUvxxieAA