How is an aurora (northern light) formed?« Back to Questions List

An aurora is an incredible colorful nightly light display. The aurora occurs in or near the Arctic and Antarctic circles. The visual light display is named after the Roman goddess of dawn.  The aurora is a natural display. It occurs when the electrically charged particles released from the sun enter the atmosphere of the earth and collide with gases such as oxygen or nitrogen.  Since aurora occurs mainly in the high latitude, it is sometimes referred as polar light. The display in the north is called aurora borealis ( northern lights). The aurora that occurs in the south is called aurora australis (southern lights). 

The surface of sun is continuously discharging electrically charged particles, mainly in the form of electrons and protons.  Some of these particles enter the atmosphere of earth as solar winds. When these particles penetrate the magnetic field of earth, they collide with gases contained in the upper atmosphere.  This collition releases energy in the form of light which appears as arcs, colored light, light streams etc.  When the solar wind is intense, the activity is faster and light display can be seen from far away by naked eyes.  

Has sun got any magnetic field like the earth?

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