Auroras are a natural light phenomenon related to charged particles of solar winds that impact the Earth’s atmosphere at high altitude. Auroras are formed by ionization of atmospheric particles when solar winds result in significant disturbances of the magnetosphere. Subsequently, the energy of these particles is lost to the atmosphere, which emits light in different colors and intensities. Auroras may occur in several forms, but are known best for their green and red bands that illuminate the sky. They can be observed at high latitudes in the Arctic, where they are called Aurora Borealis or the Northern Lights, as well as in the Antarctic, where they are called Aurora Australis or Southern Lights.
Information source: Encyclopaedia Brittannica, Wikipedia
Image: Aurora Borealis as seen from Bear Lake, Alaska, USA. Credit: US Air Force/Joshua Strang.