Aurora borealis. Bright display of the aurora borealis (or Northern Lights) over trees and snow covered mountains. An aurora is caused by the interaction between charged particles from the Sun and gas molecules in the Earth's upper atmosphere about 100 kilometres altitude. A stream of charged particles,called the solar wind,flows out into space continuously from the Sun at speeds of 400-500 kilometres per second. On reaching Earth,these energetic particles are drawn by Earth's magnetic field to the poles,where they collide with gas molecules in the upper atmosphere,causing them to emit streaks of light. Photographed at Panguingue Creek,Alaska | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Giannechini, Michael |
Bildgröße: | 4574 px × 3306 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
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