Cameras in Minnesota caught the light show known as the aurora borealis as shimmering lights danced in the sky.
Also called the “northern lights”, the aurora borealis is created by the sun emitting a solar wind that sends highly-charged electrons into the earth’s atmosphere.
Howstuffworks.com says the colors of the aurora borealis are determined by what the electrons strike in the earth’s upper atmosphere. Red happens when they collide with oxygen above 150 miles in altitude; green happens when they collide with oxygen up to 150 miles in altitude; purple happens when they collide with nitrogen above 60 miles in altitude and blue happens when they collide with nitrogen up to 60 miles in altitude.
Contrary to common myths, NASA says auroras are not caused by sunlight reflecting off the polar ice cap.
The aurora borealis is named after Aurora, the Roman goddess of dawn and Boreas, the Greek name for the north wind.
