It’s Always Sunrise Somewhere
On its return to Earth from a mission to the International Space Station in 2008, an unnamed crew member aboard the space shuttle Discovery took this picture of sunrise. The bluish line in the upper atmosphere is unrelated to the dawn. Called “airglow,” this light is always present, the product of a chemical reaction.
The Discovery is seen here from the Space Station as it’s about to dock on July 6, 2006.