Why do northern lights happen near the poles?

Auroras form when the solar wind sends fast-moving charged particles toward Earth. Our planet’s magnetic field funnels many of those particles toward the polar regions, where they strike oxygen and nitrogen high in the atmosphere. These collisions excite the gases, which then release light as they return to normal energy states. Oxygen often produces green and red light, while nitrogen can create blue or purple hues. The aurora is most common during periods of high solar activity, such as around the peak of the Sun’s roughly 11-year cycle.