The Aurora Borealis is active all year but can only be seen when the Alaska
night sky is dark from August to April.  The Aurora is a natural light display
caused by charged particles from the Sun interacting with the Earth’s Atmosphere.  When these particles
collide with Oxygen, yellow and green are produced; Nitrogen produces red, violet and rarely blue.
The colors are also affected by altitude - green/red around 150 miles; purple/violet at 60 miles.