The term 'night sky glow' can be summarized by the word 'Aurora, ' which is a natural light display in the sky, usually seen in the polar regions. Aurora is caused by the collision of energetic charged particles with atoms in the high altitude atmosphere. The particles originate in the magnetosphere and solar wind and, on Earth, are directed by the Earth's magnetic field into the atmosphere. The resulting ionization and excitation of atmospheric constituents emits light of varying color and complexity.