When the Sunset meets the Northern Lights Aurora Borealis In the early 17th century, the astronomer and scientist Galileo Galilei named this phenomenon Aurora Borealis. Aurora was the Roman goddess of dawn, and Boreas was the Greek name for the north wind. Galilei thought that an aurora was caused by the sunlight reflected from the atmosphere. This display of coloured light is caused by the interaction of the solar wind with the Earth’s magnetic field and atmosphere. The solar wind carried electrons from the sun’s atmosphere into space. These charged particles (ions) are drawn into the Earth’s magnetic field, particularly at the North and South magnetic poles, and down into the upper atmosphere (ionosphere). When the particles collide with gases in the atmosphere, energy is created. Some of this energy is given off in the form of light emissions; called the Aurora Borealis or Northern Lights in the northern hemisphere and the Aurora Australis in the southern hemisphere.