The effect is caused the interaction between the solar wind, the Earth's magnetic field and the upper atmosphere. Solar wind is composed of charged particles, so the glancing particles in the particularly strong area of the magnetic field creates what seems like an electrical fireworks display.<ref>[http://solarsystem.nasa.gov/dictionary/index.cfm?Display=Dictionary&Letter=A NASA Dictionary].</ref> | The effect is caused the interaction between the solar wind, the Earth's magnetic field and the upper atmosphere. Solar wind is composed of charged particles, so the glancing particles in the particularly strong area of the magnetic field creates what seems like an electrical fireworks display.<ref>[http://solarsystem.nasa.gov/dictionary/index.cfm?Display=Dictionary&Letter=A NASA Dictionary].</ref> |