Green bands of light pass among the stars of Big Dipper, the prominent asterism of constellation Ursa Major. The mysterious lights in the northern sky seems to be aurora or northern lights but their appearance is more similar to airglow. Which one is the source of these green bands? Atmospheric gravity waves – propagating upward into Earth’s mesopause – disturb the homogeneous green airglow layer (90 – 100 km), causing stripes and bands that can easily be seen with the naked eye from dark observing sites. Their color is only detectable in long exposure photography. For more information see this page at Atmospheric Optics.



comments (3)

  • Randolph Miller Reply

    Can you post the details of how these photos were taken? Like what ISO, exposure time, F stop, and all that good stuff?

    July 11, 2010 at 9:09 pm
  • John Rowlands Reply

    This is airglow emission, without any doubt at all. The form is entirely wrong for aurora.

    May 3, 2016 at 1:38 am
  • Ray Stinson Reply

    Wally: I have a similar image taken back in 2009 at Grand Teton National Park that shows the banding to the east with Jupiter just rising. The green glow was visible to the naked eye but showed up better with the camera. At that time I was using the canon XSI with the f3.5 kit lens.

    November 2, 2016 at 12:58 pm

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