Tuesday, December 23, 2008

No glow — Low point in sunspot cycle means little chance of Northern Lights

By Jenny Neyman
Redoubt Reporter

Clear night skies are a trade-off in Alaska. They make for frigidly cold temperatures, but they also make it possible to see one of the most colorful perks to living in the North — the aurora borealis.

Except this year. When it’s clear, it’s just cold, with little chance of getting a light show.

Aurora displays are caused by sunspots — magnetic storms on the sun. Sunspots produce particles — mostly electrons and protons — called solar wind, that shoot out toward Earth. When solar wind particles collide with Earth’s magnetosphere, it can cause light emissions as the particles slam into the atoms and molecules in Earth’s atmosphere.

Sunspot activity runs on an 11-year cycle, with some years being active, and some not so much. This would be a not-so-much year.

Andy Veh, professor of astronomy and physics at Kenai Peninsula College Kenai River Campus, said the sunspot cycle was at its maximum activity level in 2000 and 2001, and will be most active again in 2010 and 2011. But 2006 through 2008 is the low point in the cycle.

“Right now it’s, well, if you get a clear night, which are few and far between, and then you look, if it’s not there, it’s not there. If you have good luck, then it’s there. I have to admit I didn’t see any last year. This year, maybe one, I’m not sure. If they don’t move a lot, it’s tough to distinguish them from high clouds,” Veh said.

But just because the northern lights are a no-show this winter, doesn’t mean people should ignore the night sky. There are plenty of other reasons to look up.

“Instead of looking at the aurora, I noticed that Venus is out,” Veh said. “I was surprised when I saw it. I thought it was too far below the horizon in Alaska, but it’s really nice. It’s really bright when you’re driving at night to the south.”

When clear skies do happen at night, Veh recommends taking advantage of them.
“Astronomy is really hard in Alaska. It has to be really cold in order to get clear skies. So every other week we get a couple of nice nights,” he said. “The winter sky is nice because when they’re out, the brightest stars are in the winter.”

Orion, Taurus and Gemini are plenty bright and visible to the naked eye. Saturn can also be seen this time of year, rising after midnight in the east.

The Geminids meteor shower was covered by clouds last week, but the Quadrantids meteor shower may be visible to early risers on Jan. 4. Watch the sky around 6 a.m. for streaks of lights.

A good viewing spot away from man-made lights makes it easier to appreciate nature’s night lights. Veh said traveling on the Sterling Highway toward the mountains offers some dark pullouts that are good for stargazing. In town, Bridge Access Road is a decent spot, although passing traffic can interfere.

“The Kenai beach, as far as accessibility is concerned, the beach is good because you have a free view to the west and south, which you don’t have anywhere else,” he said.

Just don’t forget your mittens, since clear nights this time of year usually mean temperatures at or below zero.

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