Astronomy Picture of the Day

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.

May 6, 1996
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Southern Lights and Shuttle Glow
Credit: STS-39 Crew, NASA

Explanation: A background of distant stars, sinuous and spiky bands of Southern Lights (Aurora Australis), and the faint glow of charged plasma (ionized atomic gas) surrounding the Space Shuttle Discovery's engines give this photo from the STS-39 mission an eerie, otherworldly look. This image reflects Discovery's April 1991 mission well - its payload bay (PLB) was filled with instruments designed to study celestial objects, aurora and atmospheric phenomena, and the low Earth orbit environment around the PLB itself. The aurora seen here are at a height of about 50-80 miles and caused by charged particles in the solar wind, channeled through the van Allen Radiation Belts which excite atoms of oxygen in the upper atmosphere.

Tomorrow's picture: The Clouds of Neptune


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See Explanation.  Clicking on the picture will download 
 the highest resolution version available. See Explanation.  Clicking on the picture will download 
 the highest resolution version available. Top 5 logo See Explanation.  Clicking on the picture will download 
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Authors & editors: Robert Nemiroff (GMU) & Jerry Bonnell (USRA).
NASA Technical Rep.: Sherri Calvo. Specific rights apply.
A service of: LHEA at NASA/ GSFC