As the name suggests, the Aurora Borealis (Northern Lights) are especially related to polar regions, and occur in a 2,500 km radius centered on the magnetic north pole.
Interestingly, the earth isn’t the only planet with aurora. Jupiter and Saturn have auroral ovals on both hemispheres. Astronomers have also spotted aurora on Uranus and Neptune.
Aircraft crews on transpolar flights and astronauts experience higher doses of radiation during periods of intense solar activity.
The lights also produce a strange sound -- similar to the sound of applause.
In some areas, such as Alaska or Greenland, they may be visible most nights of the year. They occur at any time of the day, but can’t bee seen with the naked eye unless it’s dark.
The earliest known account of northern lights appears to be from a Babylonian clay tablet from observations made by the official astronomers of King Nebuchadnezzar II, 568/567 BC.