Aurora Borealis occurs when materials from the surface of the Sun collide with the atmosphere of the Earth. Experts make predictions about the occurrence of Aurora Borealis based on events taking place on the Sun and the speed of matter being thrown from the Sun's surface. Aurora Borealis is visible in portions of the Northern Hemisphere, including Canada, Scandinavia, North America, Siberia and Northern Europe.
Aurora Borealis affects radio and satellite communications. The name Aurora comes from the Roman goddess of dawn. Borealis comes from the Greek word Boreas, which means North wind. Borealis was a name given by Pierre Gassendi in 1621. Ancient civilizations believed the lights were gods and goddesses manifesting themselves to mortals, and many believed the lights were spirits dancing in the sky, such as the Cree people who called it Dance of the Spirits. The lights were thought to be signs from God in Medieval Europe. In other cultures, the red lighting was associated with stories and legends pertaining to murder, death and warfare. Red is the dominant color of Aurora Borealis. Other colors include blue, violet and green. The lights move and sway back and forth in the sky, and the lights disappear and reform minutes later. There is a Southern counterpart to Aurora Borealis known as Aurora Australis, which has properties similar to the Northern Lights. Aurora Australis may be seen in South America and Antarctica.