The aurora borealis, more commonly known as the northern lights, are radiant shimmering colors that sporadically light up the night sky and have fascinated mankind for ages. Aurora comes from the Latin word for sunrise and borealis mean to the north.
Aurora Borealis' occur sporadically over the middle and high latitudes of the northern hemisphere. The chances of seeing the northern lights is a combination of the type of radiation produced by the Sun, location on the Earth, and having clear skies at night. Chances increase slightly during the winter because there are more hours of darkness.
The Earth is constantly being bombarded with debris, radiation, and other magnetic waves from space. Most of the time, the Earth's own magnetic field does an excellent job of deflecting these potentially harmful rays and particles.
When charged particles from the Sun encounter the Earth's magnetosphere, the particles are deflected by magnetosphere's spiraling motion around the field lines. This deflection slows the particles streaming from the Sun, causing them to flow around the Earth much as water in a stream is diverted by a rock.
Sometimes the particles penetrate the Earth's magnetosphere and collide with nitrogen and oxygen atoms in our atmosphere. Thus releases photon energy in the form of amazing aurora lights. The color of the aurora depends on which atom is struck, and the altitude of the collision.
Green: oxygen, up to 150 miles in altitude
Red: oxygen, above 150 miles in altitude
Blue: nitrogen, up to 60 miles in altitude
Purple: nitrogen, above 60 miles in altitude
When these constantly shifting magnetic and electrical forces react with one another, the aurora appears to dance in the night sky.
What You Will See
The northern lights will appear as streaks or cloud-like patches of light. Depending on their intensity the lights might be just a patch of band on the northern horizon; at higher intensities the northern lights can fill the entire sky. The lights will usually be white or a pale green, but will sometimes appear in colors such as yellow, red, blue, or even purple.
If you're uncertain if that patch of light is indeed the northern lights, watch and be patient; the northern lights can disappear completely, only to regain their brightness minutes later. If the patch grows brighter, fades, then reappears it is most likely the northern lights. When the conditions are right, the northern lights offer an entrancing, almost magical display that fascinates all who see it, a true North Woods experience.
When to View
Solar storms on our sun send streams of particles toward the Earth which can increase the intensity of the northern lights. You can monitor the levels of solar storms by searching the Internet for sites that offer "aurora forecasts". One such site is provided by the University of Alaska at Fairbanks: http://www.gi.alaska.edu/AuroraForecast. Best viewing occurs when the arrival of the solar radiation and particles corresponds with an evening when moonlight is at a minimum and the weather outside is clear.
Northern Lights at Voyageurs
Located on the Canadian border, Voyageurs National Park offers visitors some of the best conditions to view the night skies. Surrounded by miles of lakes and wilderness area, the skies above Voyageurs are free of the excessive, misdirected, and obtrusive artificial light produced by the large urban cities across America.
Suggested locations to view the northern lights in Voyageurs National Park: