Aurora borealis. Aurora borealis (northern lights) display and star trails over silhouetted conifer trees. Star trails are caused by the apparent motion of the stars due to the Earth's rotation during the long photographic exposure. Aurorae are caused when charged particles from the Sun (the solar wind) are drawn to the Earth's poles by its magnetic field. They collide with gas molecules in the upper atmosphere about 100 kilometres up,causing them to emit light. Photographed on 8-9th April 1999 from near Atlin,British Columbia,Canada | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Sirulnikoff, Alan |
Bildgröße: | 3164 px × 4538 px |
Modell-Rechte: | nicht erforderlich |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |