The Colors Of Aurora
As charged particles from the sun come in contact with atoms of nitrogen and oxygen in earth’s atmosphere energy is released. This usually happens at very high altitudes around 90-130 km. The energy released in the spectrum of visible light is the colors that we can see or capture. The color produced depends on which atom is struck oxygen or nitrogen and at what altitude. If a particle collides with an oxygen atom at lower altitudes the color green is produced. Red can be seen if particles come in contact with oxygen at very high altitudes. Blue is produced if an particle collides with nitrogen at lower altitudes, and the color purple/violet if the collision is at high altitude.
(by Friðþjófur M.)