Aurora

1. a natural electrical phenomenon characterized by the appearance of streamers of reddish or greenish light in the sky, especially near the northern or southern magnetic pole. The effect is caused by the interaction of charged particles from the sun with atoms in the upper atmosphere. In northern and southern regions it is respectively called aurora borealis or Northern Lights and aurora australis or Southern Lights.
2. the dawn.

late Middle English (originally in aurora (sense 2)): from Latin, ‘dawn, goddess of the dawn’. aurora (sense 1) dates from the early 18th century.