What Causes the Northern Lights to Appear in Different Colours?
The Northern Lights, also known as the aurora borealis, occur when charged particles from the Sun interact with Earth's magnetic field and collide with gases in the upper atmosphere. These collisions transfer energy to atmospheric atoms and molecules, which release light as they return to lower-energy states. The colour depends largely on the type of gas involved and the altitude of the interaction. Oxygen commonly produces green light and can produce red light at higher altitudes. Nitrogen can contribute blue, violet, and pink shades. The auroras are most frequently visible at high latitudes near the Arctic, where Earth's magnetic field guides charged particles toward the atmosphere. Solar storms can intensify the displays and make them visible farther from the poles. The Southern Lights, or aurora australis, develop through similar processes in the Southern Hemisphere.
