The dark of winter is the time to see the mysterious dancing lights, although sightings in these parts are rare. Read on to find out what conditions make them possible:
What are the northern lights?
The northern lights could be called space weather. They happen when electrically charged particles from the sun’s atmosphere collide with gaseous particles in Earth’s upper atmosphere. Solar winds carrying the particles are attracted by Earth’s magnetic field to the north and south poles where the aurora forms an irregular oval shape. The scientific name of the phenomenon is the aurora borealis in the northern hemisphere and the aurora australis in the southern hemisphere.
Why do the lights change color and move?
The lights take many shapes including glowing clouds, blinking lights, rays, arcs or flowing curtains. The colors of the lights change as solar particles interact with different gas particles. The most common color is a yellowish-green caused by oxygen molecules. Blue or purplish-red is caused by nitrogen. The rarest color, pure red, is caused by oxygen at high-altitudes, according to the Canadian Northern Lights Center website.
Where is the best place to see the northern lights?
The best place to see the lights is near the Earth’s poles. At 60 to 75 degrees north latitude the aurora is visible more than half of the nights of a given year, according to the National Oceanic and Atmospheric Administration Space Weather Prediction Center. The center offers a daily aurora forecast online as does the University of Alaska Fairbanks Geophysical Institute.
What makes it possible to see the lights in north Idaho and eastern Washington?
Major geomagnetic storms cause the auroras to expand away from the poles so that occasionally they can be seen as far away as Texas. Geomagnetic storms are measured with something called the Planetary K-index. Anything above Kp 5 is considered a storm. The Palouse and Lewiston-Clarkston Valley are at 46 degrees north latitude and a strength of Kp 7 would make it possible to see the lights here, according to the center’s website, which provides K-index forecasts.
If solar flares disrupt your radio or mobile phone reception it’s a good time to look for the aurora. Get far away from city lights around midnight on a clear night with no moon for the best viewing.
Some sites providing aurora forecasts: http://www.swpc.noaa.gov/ http://www.aurora-service.org http://www.gi.alaska.edu/
