How are the Northern Lights formed?

Hey there,
  

                  The northern lights, or aurora borealis, offer an entrancing display of colourful lights— but just what causes this magical natural sight?

The Aurora Borealis is caused by collisions between gaseous particles in the Earth's atmosphere with charged particles released from the sun's atmosphere. Different colours are due to the type of gas particles that are colliding. The most common colour, a pale yellowish-green, is made by oxygen molecules located about 60 miles above the earth.

Blue light is produced by nitrogen and rare all-red auroras are produced by high-altitude oxygen.

Image Credit: NASA

Above the surface of the sun, the temperature is millions of degrees Celsius. At this high temperature, collisions between gas molecules are frequent and cause explosions. This causes free electrons and protons to be thrown from the sun's atmosphere and escape through holes in the magnetic field. These charged particles move towards the earth by the solar wind, and many are deflected by the earth's magnetic field. However, the earth's magnetic field is weaker at either pole which allows some particles enter the earth's atmosphere and crash with gas particles. These collisions throw out light that we see as the dancing lights of the north

Here is  a video that is creative and simple by the Department of Physics, University of Oslo:

Emily ✵

References:
http://www.aurorahunter.com/how-the-aurora-borealis-form.php
http://www.northernlightscentre.ca/northernlights.html