 EPOD - a service of USRA

The Earth Science Picture of the Day (EPOD) highlights the diverse processes
and phenomena which shape our planet and our lives. EPOD will collect and
archive photos, imagery, graphics, and artwork with short explanatory
captions and links exemplifying features within the Earth system. The
community is invited to contribute digital imagery, short captions and
relevant links.


 Archive - Aurora Observed from Space Station

   January 16, 2021

    Iss006-e-47517_540

   Every weekend we present a notable item from our archives. This EPOD
   was originally published January 16, 2004.

   Provided by:  NASA Earth Observatory
   Summary authors & editors:  Earth Observatory;  Jim Foster

   According to Expedition 6 Science Officer Don Pettit, aboard the
   International Space Station (ISS), being in orbit around the Earth
   offers a unique perspective on auroras. He mentioned that when their
   orbit coincided with local midnight at high latitudes, the lights were
   turned down so that it was possible to peer out the windows at the
   breathtaking views of the shimmering northern lights. The above photo
   was taken from the ISS as it orbited over the Southern Hemisphere,
   approximately 400 km above the Earth’s surface, on April 20, 2003.

   Most of the auroral light is emitted by oxygen atoms excited from
   bombardment by charged solar particles. Charged particles consisting of
   atomic fragments released by the Sun stream through space and run into
   Earth’s magnetic field. When a charged particle encounters our magnetic
   field, a force perpendicular to the motion is created, which diverts
   the particle into a spiral path until it collides with atoms in the
   upper atmosphere. The collisions excite the atoms (oxygen and nitrogen)
   into emitting light, in much the same way that electrons pumped inside
   of a glass tube filled with neon gas create a neon light. Green light
   is the color most commonly observed. It's emitted from excited oxygen,
   centered around a wavelength in the electromagnetic spectrum of 558
   nanometers. Red light, emitted about wavelengths in the 630 nanometer
   region, is less infrequently observed. Green emissions extend from
   about 100 km altitude to approximately 300 km, whereas the red
   emissions lie on top of the green and extend to perhaps 500 km.


Related EPODs

    Archive - Aurora Observed from Space Station  The Golden Hour at
   Rocky Mountain National Park  Lunar Fogbow Observed in Saxony,
   Germany  Parisian Sky: Glaciating Virga  Crepuscular Rays over
   the Roof Tops of Manchester  November Gales on Lake Michigan
    More...

Atmospheric Effects Links

     *  Atmospheric Optics
     *  Color and Light in Nature
     *  The Colors of Twillight and Sunset
     *  Refraction Index
     *  Image Gallery: Atmospheric Effects
     *  What is a Rainbow?

-
   Earth Science Picture of the Day is a service of the  Universities
   Space Research Association.

https://epod.usra.edu
 
