The aurora borealis—also known as the northern lights—is a natural phenomenon that occurs at the northernmost points of Earth. These amazing light displays are most commonly seen in the sky in areas near the North Pole, such as northern Canada, the U.S. state of Alaska, Greenland, and Scandinavia. Auroras are caused when the sun creates high-energy gas called solar wind. When this wind reaches our planet, it hits Earth’s magnetic field, and this creates electrical currents. The electrical currents begin to travel along the surface of Earth’s atmosphere, and they gather more and more energy until they reach the poles. The light of the aurora is created when these high-energy electrical particles mix with other gases, such as oxygen and nitrogen. Auroras may be very different in size and appearance. These colors and shapes depend on the amounts and types of gases that are present in the atmosphere at the time the auroras happen. There are also auroras that occur at the southernmost tip of Earth. Those are known as aurora australis.