<p>A brilliant green <a id="o00c" title="aurora" href="http://photography.nationalgeographic.com/photography/photos/patterns-aurorae/#/churchill-aurora_9338_600x450.jpg">aurora</a> seems to flow like a river in the skies over <a id="wo7q" title="Tromsø, Norway (map)" href="http://maps.nationalgeographic.com/map-machine#s=r&amp;c=69.65899581985833, 18.966522216796875&amp;z=9">Tromsø, Norway (map)</a>, in a long-exposure picture taken between late Saturday and early Sunday.</p><p>Aurorae are created as charged particles, which are constantly streaming from the sun, travel along Earth's magnetic field lines and collide with atoms in the planet's atmosphere. The light shows can be more intense—and can sometimes be seen farther from the Poles—during solar storms.</p><p>(See <a id="m4e-" title="pictures of unusual auroras sparked by a solar storm in August" href="http://news.nationalgeographic.com/news/2010/08/photogalleries/100810-northern-lights-solar-cme-aurora-borealis-pictures/">pictures of unusual aurorae sparked by a solar storm in August</a>.)</p>

Island Aurora

A brilliant green aurora seems to flow like a river in the skies over Tromsø, Norway (map), in a long-exposure picture taken between late Saturday and early Sunday.

Aurorae are created as charged particles, which are constantly streaming from the sun, travel along Earth's magnetic field lines and collide with atoms in the planet's atmosphere. The light shows can be more intense—and can sometimes be seen farther from the Poles—during solar storms.

(See pictures of unusual aurorae sparked by a solar storm in August.)

Photograph by Thilo Bubek

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