We have been studying magnetism and we have discovered that norhtern lights have a lot to do with this. But why do the norhtern lights happen? Well, as we have discovered, there is a solar wind. These winds send charged particles into space that travel at a very high speed and collide against the magnetosphere.
But sometimes the solar winds are very violent and explosions occur in the Sun (solar flares). It is with the solar flares when we see the norhtern lights, as these charged particles from the Sun collide with the gas atoms in the atmosphere. Each gas creates a different colour.