Just What Are Those Lights in the Sky?

THE closer you are to the north pole, the better your opportunities for seeing the aurora borealis. If you were in Alaska or northern Canada during the winter, you would see the northern lights 1 night out of every 3. But even the northernmost parts of the lower 48 states see auroras occasionally - about 20 to 25 times a year. Displays like the one Max and Mr. Rosiello saw are rare. But don't stop looking - during the spring of 1989, places as far south as southern California and Florida witnessed spectacular shows.

Near city lights, under cloudy or polluted skies, or next to forests and mountains, it's difficult to see the aurora borealis. The best place to watch is open land away from lights. The best time is around midnight on a moonless night. Most often, you'll glimpse the aurora as a pale green, misty glow on the northern horizon. If you spot this early in the evening, don't go to bed! Stay up to see if it develops into a full display.

Climatologists (weather professionals) are getting better at predicting the northern lights. How do they know if an aurora will occur? They watch for sunspots and solar flares - great eruptions on the sun's surface.

These explosions shoot out clouds of high-speed, charged particles. Unlike the usual spray of sun particles, these penetrate the magnetic layer of our atmosphere (the ionosphere). When the ionosphere atoms are bombarded by the charged particles, they emit radiation, or light, in different colors. If climatologists or astronomers see solar flares and sunspots, they know an aurora may occur in a couple of days.

The sun particles move along magnetic lines toward the earth's poles. The aurora borealis has a twin at the south pole called the aurora australis, or southern lights. If you were looking from outer space you'd see both auroras occurring at the same time!

Maybe you've read ancient stories called the Greek and Roman myths. You might have stumbled across Aurora and Boreas. Gentle and beautiful, Aurora was the goddess of the dawn and the mother of the four winds. Boreas was the north wind. Can you imagine how the dawn might look, if the wind blew across it? You might picture what Max and Mr. Rosiello saw: a rippling curtain of light. Perhaps that's why people called the northern lights ``aurora borealis.''