ABSTRACT
The shimmering, dancing lights of the Aurora Borealis and the Aurora Australis are certainly one of the most mystical and unforgettable phenomena of the night sky. This chapter reviews the origins of the aurorae and the role of the earth's magnetic field so that we may predict when and where they are likely to occur. The sun is constantly hurling incomprehensible quantities of electrons, protons, and a host of other subatomic particles into space at immense speeds. When the particles emitted from the sun collide with the gas molecules in the earth's upper atmosphere, they interact and cause the gas molecules to emit light. Displays of the aurora occur every day of the year, day or night. However, most displays are insignificant and only visible at extremely high latitudes. Airglow originates from the same atomic process that produces the aurora, namely, the emission of light from electronic transitions within individual oxygen atoms and compound molecules.
