The northern lights are caused by charged particles from the Sun colliding with gases in Earth's atmosphere.

The Sun constantly releases a stream of charged particles called the solar wind. When these particles reach Earth, most are blocked by its magnetic field, but some get funneled toward the poles. There, they slam into oxygen and nitrogen atoms high in the atmosphere. This collision excites the atoms, making them release light in different colors, creating the aurora borealis, or northern lights.