The Aurora Borealis displays different colors based on which atmospheric gases are being excited by solar particles and at what altitude the interactions occur. The most common colors are:
- Green: Caused by oxygen atoms at 60-150 km altitude
- Red: Produced by oxygen at higher altitudes (150-300 km)
- Blue/Purple: Created by nitrogen at lower altitudes
- Pink: A mixture of nitrogen and oxygen reactions
When charged particles from the sun collide with these atmospheric gases, they cause the gases to emit light at specific wavelengths, creating the spectacular light show we see. The intensity and mix of colors depend on the strength of the solar activity and the composition of the upper atmosphere.