Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2006 February 4
Explanation: A nearly full Moon and planet Earth's shadow set together in this scene captured on January 13th from snowy Mt. Jelm, home of the Wyoming Infrared Observatory. For early morning risers (and late to bed astronomers), shadow set in the western sky is a daily apparition whose subtle beauty is often overlooked in favour of the more colourful eastern horizon. Extending through the dense atmosphere, Earth's setting shadow is seen in this picture as a dark blue band along the distant horizon, bounded above by a pinkish glow or antitwilight arch. Known as the Belt of Venus, the arch's lovely colour is due to backscattering of reddened light from the rising Sun. The setting Moon's light is also reddened by the long sight-line through the atmosphere.
Authors & editors:
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: EUD at NASA / GSFC
& Michigan Tech. U.