Banded Airglow. This image by Doug Zubenel taken in Nebraska nicely shows the airglow's sometimes banded and patchy structure. They change imperceptably over minutes or tens of minutes and arise as slowly moving gravity waves at the airglow's height of 90-100 km modulate the tenuous gas density and temperature. Measurements of airglow intensity and spectra give insight on the mesosphere - lower thermosphere region. Imaged in Cherry County, Nebraska, 2300 CDT July 23,2000. The field measures 41°X27°. 50mm lens at f/2.8, 15 minute guided exposure on Fuji NHG II 800. Image ©Doug Zubenel, shown with permission.