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image credit & copyright: Stephane Vetter (TWAN, Nuits sacrees)




a sensitive video camera on a summit of the Vosges mountains in France captured these surprising fireworks above a distant horizon on june 26

generated over intense thunderstorms, this one about 260 kilometres away, the brief and mysterious flashes have come to be known as red sprites

the transient luminous events are caused by electrical breakdown at altitudes of 50 to 100 kilometres

that puts them in the mesophere, the coldest layer of planet Earth's atmosphere

the glow beneath the sprites is from more familiar lighting though, below the storm clouds

but on the right, the video frames have captured another summertime apparition from the mesophere

the silvery veins of light are polar mesospheric clouds

also known as noctilucent or night shining clouds, the icy clouds still reflect the sunlight when the Sun is below the horizon




















































in apod.nasa.gov/apod