Photograph from NASA via AFP/Getty Images
The soft green glow of the aurora borealis seems to swaddle the Pacific Northwest in a recently released picture taken by astronauts aboard theInternational Space Station.
Familiar green auroras appear lower in the atmosphere, around 60 miles (100 kilometers) above the surface. At altitudes round 185 to 310 miles (300 to 500 kilometers), the light displays are pure red. (See more aurora pictures.)
To the right in this frame, the bluish shine of a phenomenon called airglow—light spawned by various chemical interactions in the upper atmosphere—peeks from beneath the auroral blanket.