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.

February 22, 1998
See Explanation.  Clicking on the picture will download 
 the highest resolution version available.

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. Aurora are caused by charged particles in the solar wind, channeled through the Earth's magnetic field which excite molecules in the upper atmosphere.

Tomorrow's picture: M104: The Sombrero Galaxy

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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
&: Michigan Tech. U.