FAIRBANKS, Alaska — Just south of the Arctic Circle, as spring arrives, the forecast on the front page of the newspaper is cheery: "Another sunny, chilly day." That means we're looking for a high of 12 and a low of -20.
The low end of that forecast means something to me and my fellow travelers: We will spend the midnight hours and beyond outside, in the wind, on a mountaintop 20 miles north of town. It also matters that the skies will be clear. We are here to see the Northern Lights, the aurora borealis, the greatest light show on Earth. (Actually, it is one of two such shows. Its mirror version, aurora australis, goes on at the South Pole, where, it should be noted, -20 would be warm.)
Fairbanks, population 32,650, is a hunkered-down town between the Arctic Circle and Mt. McKinley. That puts it right in the middle-the interior, as it is called-of the country's largest and, some would say, most inaccessible state.
Fairbanks passes muster in the lodging and dining categories, but that's not why people come here. They come for a taste of life on the edge of the planet, where there are vast expanses of unsettled land and, in summer, sunshine at midnight. During my visit in mid-March, Fairbanks was hosting the North American Championship Sled Dog Races and the World Ice Art Championships. The races were downtown, the ice sculptures next to my motel. Both were genuine attractions, and I took them in, but they were not my main reason for coming.
I was here, like increasing numbers of visitors, to look at the sky.
Aurora seekers bring with them an interest in nature, in astronomy, in physics, in spiritual enlightenment, in photography or in none or all of the above. I fall in the all-or-none-of-the-above category. I caught aurora fever from a friend in San Diego who had heard about the trip at an astronomy lecture. For her, it was all about the aurora; for me, it was also an excellent excuse to make good on my long-standing intention to see Alaska. The five-day trip came with no guarantee that we would see an aurora, but it was timed to be a good bet. We signed on.
Although auroras can be devilishly unpredictable, this year and next are expected to be a time of extraordinary solar activity and, therefore, extraordinary auroras. Spring and fall near the equinox are considered the best times. Those seasons strike a balance between two important factors: dark skies and cold weather. In summer, it's light all night so the aurora doesn't show up; in winter, it is so cold that even the locals don't like to venture out much because temperatures can sink to -60. Cloud cover, which can occur any time of year, is always a wild card.
A spring trip has an intangible benefit: Freshly freed from winter, Alaskans are happy to see you.
Viewing conditions should be good through this month. There is still enough nighttime, and temperatures are on average 20 degrees warmer than in March. Like the climate, daylight changes quickly here, increasing or decreasing six to eight minutes a day.
Fairbanks is a great place to see and study the aurora, both for tourists and scientists. The aurora occurs in a ring around the magnetic North Pole, and most of the time, Fairbanks is right under the auroral ring. When there's a lot of solar activity, the size of the ring expands, which means that occasionally there is a great show in lower latitudes, even, say, in Iowa or New Jersey. In recent weeks, the aurora has really been going wild: People have caught glimpses as far south as Palm Springs and Phoenix.
Solar storms and flares are key to aurora displays because they send electrically charged particles from the sun hurtling into space, some of them toward Earth. Those that get caught up in Earth's magnetic fields end up unleashing tremendous energy in the form of light, and sometimes wreak havoc on radio transmissions and power plants.
Like tall, thin sheets shifting in the breeze, the aurora moves in swirls across the sky, following the lines of the magnetic field. The light feels close but isn't really. The bottom edges of those sheets are 60 miles above Earth, and the light extends several hundred miles upward. The swirls can move from horizon to horizon, or in smaller sweeps. White and green are the predominant colors, with touches of pink and sometimes red. It's difficult to capture on film exactly what the eye sees; film can pick up additional color because of long exposures and, of course, can't relay the motion.
My group was getting some lessons in how all this works from scientists at the University of Alaska's Geophysical Institute who study the aurora, including tracking it by radar and launching rockets into it from the Poker Flat Research Range outside town. We heard about the science of the aurora from Neal Brown, founding director of the Poker Flat facility, who now does educational outreach at the institute, and we learned about photographing the aurora from Jan Curtis, a meteorologist who has fallen under its spell.