nubbsgalore: the colours rippling through these night skies are from atmospheric airglow and the gravity waves passing through them. airglow is the result of chemiluminescence in the thermosphere, where ultraviolet radiation from the sun excites atoms, mostly oxygen and nitrogen, which emit photons (or varying wavelengths of light that correspond to a colour on the visible spectrum) as they collide to form new molecules like nitric oxide. airglow can look rippled when gravity (or buoyancy, and not gravitational) waves pass through the atmosphere. whether from the updraft of a storm or air moving over mountainous terrain, a wave can form in a stable layer of the atmosphere, which grows as it rises from the lessening atmospheric pressure. photos were taken by (click pic) yuri beletsky, graeme whipps, dave lane, marcko korosec, jeff zylland, jeff dai and chris cook. – Gatlinburg Garden Castle Rainbow Tower Library Imagination Station Temple Water Spirit Guardian Labyrinth Treasury Magic Healing