Clouds, Airglow, and Stars

Air glows all of the time, but it is usually hard to see. A disturbance however — like an approaching storm — may cause noticeable rippling in the Earth’s atmosphere. These shock waves are oscillations in air analogous to those created when a rock is thrown in calm water. The image was captured during a climb up Mount Pico in the Azores of Portugal. Ground lights in the center originate from the island of Faial in the Atlantic Ocean.