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            This is a file from the  Wikimedia Commons. Information from its  description page there is shown below.  Commons is a freely licensed media file repository.  You can help. 
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           | Description | 
           The  Aurora Australis as seen from the  Space Shuttle  Discovery on  STS-39. The payload bay and tail of Discovery can be seen on the left hand side of the picture. Auroras are caused when high-energy electrons pour down from the Earth’s magnetosphere and collide with atoms. Red aurora occurs from 200 km to as high as 500 km altitude and is caused by the emission of 6300 Angstrom wavelength light from oxygen atoms. Green aurora occurs from about 100 km to 250 km altitude and is caused by the emission of 5577 Angstrom wavelength light from oxygen atoms. The light is emitted when the atoms return to their original unexcited state. | 
          
          
           | Date | 
           May 1991 | 
          
          
           | Source | 
            http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=4800 | 
          
          
           | Author | 
           NASA (Crew of STS-39)  (Original uploader was  Seth Ilys at  en.wikipedia) | 
          
          
           Permission ( Reusing this file) | 
           
            
             
              
               | Public domainPublic domainfalsefalse | 
               
              
             
              
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               This file is in the  public domain because it was solely created by  NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See  Template:PD-USGov,  NASA copyright policy page or  JPL Image Use Policy.) | 
               
                
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          This image or video was catalogued by one of the centers of the United States  National Aeronautics and Space Administration (NASA) under Photo ID: STS039-342-28.   This tag does not indicate the copyright status of the attached work. A normal  copyright tag is still required. See  Commons:Licensing for more information. 
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