The aurora, or northern lights, are a natural phenomenon caused when electrically charged particles from the sun enter the earth’s atmosphere. The particles are pulled by the earth’s magnetic force, which channels them towards our geomagnetic poles.
When these particles collide with the gas atoms and molecules of the earth’s atmosphere, the lights of the aurora are emitted. The more collisions, the brighter the lights.
The different colours of the aurora are created by particles colliding with different gasses in our atmosphere. As the earth has two magnetic poles, we get the aurora borealis at the North Pole and the aurora australis at the South Pole.