Aurora or Airglow?
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.