COEUR d’ALENE — For thousands of years, the aurora borealis has fascinated sky-gazers. This week, North Idahoans have had a rare chance to see it.

The aurora is the Earth’s atmospheric response to solar radiation spikes ejected from the sun. The northern lights are most often visible closer to the North Pole, in places like Alaska and Scandinavia, due to the sun’s activity.

Space weather experts monitor sun activity and solar flares in order to predict when the aurora will appear. A solar storm this week heralded auroral activity in Idaho and other states where the lights are not usually visible.

“You have to be fortunate enough for it to be nighttime and you have to have mainly clear skies to be able to see it,” said Greg Koch, weather forecaster with National Weather Service Spokane.

Most often seen in a striking green color, the aurora sometimes shows off other hues, ranging from red and pink to purple and blue. Thursday night, near the Idaho/Montana state line, Spirit Lake resident Jenay Blackwell photographed a brilliant magenta aurora.

When charged particles from the sun hit Earth’s atmosphere, they give off light. Different atoms give off different colors.

About 60 miles up, oxygen gives off the familiar yellow-green glow. At higher altitudes, oxygen produces red auroras. Blue auroras are due to ionic nitrogen, while neutral nitrogen produces a purplish-red color.

The aurora’s colors don’t appear as bright to the naked eye as they do in photographs. Taking photos of the phenomenon can reveal more color. It helps to take long-exposure photos, whether with a camera or a phone.

“That really helps to pick out these colors that you can’t see with the naked eye,” Koch said.