Sky on fire

Visitors from the Lower 48 coming to Alaska in the winter rave about how lucky Alaskans are. It surely isn't the snow, and it couldn't be the sub-zero temperatures they rave about, could it?

No. It's the northern lights -- a natural phenomenon Alaskans often take for granted, but one about which visitors marvel. The aurora borealis are visible to us all the time in the winter, but until you go through a winter without them, you probably don't even realize how special they are.

True northern lights aficionados know the routine. It begins with a simple phone call from a neighbor, a friend or a family member.

"Look outside. The northern lights are unbelievable about there," the caller will say.

"Okay. I'll call you back," you say.

After bundling up with enough winter gear to overheat a polar bear, you trudge outside, and end up sitting in a snowbank for two hours, just watching, in admiration of nature and all that it beholds. Blues, reds and greens dance across the sky, forming patterns unimaginable beforehand. Before you realize you are cold, you realize it's 1 a.m. and you've been watching nature paint a picture for the last two hours.

But what exactly guides that paintbrush in the sky? The answer is a bit technical.

The sun is continually tossing positive ions our way due to the process that it takes to keep the sun burning. When the particles get close to our planet, they get "sucked" to the North Pole and South Pole because of the magnetism of the Earth.

`In our atmosphere, they are moving fast and knock electrons out of atoms in the upper atmosphere, and when those loose atoms are caught by another atom, light is emitted, and you get that phone call in the middle of the night that the aurora borealis are shining. Near the South Pole, the visible lights are called the corona borealis.

One of the biggest points of discussion regarding the northern lights is that of sound. Some contend that during the most intense shows of northern lights, they can actually hear them. There are two sounds that are most often talked about -- a "swishing" sound that moves with the lights' movement, and a "crackling sound."

According to the University of Alaska Fairbanks' Geophysical Institute, attempts to record the aurora have failed to prove sound exists. The first type of sound -- the swishing sound -- is often discounted because of a number of reasons. Most importantly, because of the distance of the lights, sound would be delayed by a few seconds, and wouldn't be "in tune" with movement.

The crackling sound, however, is a bit more mysterious. The sound -- like that of static electricity -- could be explained by, according to UAF, "the strong electric and magnetic fields associated with the aurora," but so far, theories haven't provided an answer.

Don't tell that to people have heard it, though. A perfect example is the 1999 Iditarod. With temperatures plummeting to -50 in McGrath and absolutely no cloud cover, the display of the aurora borealis were simply unbelievable.

As musher after musher checked into the small Bush community, every one of them talked about how impressive the display was, and about the sound.

"I swear, I heard them crackling," Rick Swenson said when arriving into the checkpoint. "That's one of the best shows I've seen."