Explanation:
What's happening to the Moon?
Drifting around the Earth in 2006 July, astronauts from the
International Space Station (ISS) captured a
crescent Moon floating far beyond the horizon.
The captured above image is interesting because part of the
Moon appears blue,
and because part of the moon appears missing.
Both effects are created by the
Earth's atmosphere.
Air molecules
more efficiently scatter increasingly blue light, making the clear
day sky blue for ground observers, and the horizon blue for astronauts.
Besides reflecting sunlight, these
atmospheric molecules
also deflect moonlight, making the lower part of the moon appear to fade away.
As one looks higher in the
photograph, the increasingly thin atmosphere appears to
fade to black.
