People in Finland got to feast their eyes on a very special sight: The Aurora Borealis, or Northern Lights. The natural phenomenon illuminates the night in the northernmost regions of the world. A similar phenomenon, known as the Aurora Australis, happens in the Southern hemisphere. What causes these otherworldly lights? Electrons from the sun collide with oxygen and nitrogen molecules in the upper atmosphere of the Earth. This ultimately results in the release of energy, in the form of light.