This 15 second long-exposure image was taken under the glowing pink and green Aurora Borealis from a mountain peak near Chena Hot Springs, near Fairbanks, Alaska.
So one of the things I found very interesting about the Northern Lights is how long-exposure images actually show the color better than the human eye can see. On a few occasions, our guide Dennis, would check the sky with a long-exposure capture just to see if there was any color (usually green). This would tell us if there was any aurora activity versus just some thin clouds. In fact, to the untrained eye, the faint aurora looks just like thin clouds.