The term aurora borealis was first used by Galileo to suggest the likeness of these lights to an early dawn in the northern sky. Actually, the aurora is a radiant emission in the upper atmosphere, between about 75 and 500 kilometers above the Earth's surface, that occurs over the high latitudes in the form of luminous bands, arcs, or streamers. The glow of the aurora is caused by atoms and molecules in the Earth's atmosphere being bombarded by charged particles, electrons and protons (hydrogen nuclei), which stream-out from the Sun and are guided by the Earth's magnetic field. These charged particles are known as the solar wind.

The aurora, as seen from satellites, is an oval ring that pivots about the Earth's geomagnetic poles. The north geomagnetic pole is not located at the north geographic pole, but instead is found about 1000 kilometers to the south near Bathurst Island in northern Canada. The auroral ring expands and contracts depending on how active the Sun is at any particular time. Every ten years or so the ring expands far enough to the south so that it can be seen in Virginia, or Oklahoma or California. Most of the time though, it is positioned over northern Canada, Alaska, northern Siberia and Scandinavia. Because the Earth's magnetic field varies with longitude as well as latitude, the aurora can perhaps be seen a few more nights a year in Alaska and northern Canada than in Scandinavia, Russia or even at the North Pole.

The above discussion pertains to winter in the Northern Hemisphere. During the months May through August, the best place to see the aurora is in Antarctica (aurora australis). It is too bright in Alaska and most of Canada during the summer to easily see the aurora. However, in southern Canada and along the border of the northern U.S., auroral displays can be seen in the summer. In these places it gets dark enough at night so that it is still possible to see them.

Question: If you wanted to see the northern lights, where would you go to get the best view?

11/22/95