Solar flare may light up our sky

It may have felt like the sun has been exploding for the past few weeks, but on Thursday it did, giving us a possible atmospheric fireworks show this weekend.

On Thursday afternoon, sunspot AR1520 belched a wave of radiation and sun bits toward Earth, causing some satellite and radio issues in the middle of the day.

The explosion bits that don't travel at the speed of light, known as the coronal mass ejection, are expected to hit Earth's magnetic field around 7 a.m. Saturday, according to the latest estimates from the National Weather Service's Space Weather Prediction Center.

This sort of magnetic clash is what causes the colorful waves in the sky known as the Aurora Borealis, in the Northern Hemisphere.

The flare is rated as X-class, which is the largest of the SWPC's categories for solar flares. This one, though, is small for an X-class; on a scale from 1 to 20, it is rated 1.4.

Still the SWPC expects category G1 geomagnetic activity on Saturday, which is minor, "commonly visible at high latitudes (northern Michigan and Maine)" according to their website, http://www.swpc.noaa.gov.

Through Sunday, that is expected to go up to G2, or moderate, which "has been seen as low as New York and Idaho."

The SWPC offers a few other tips to keep in mind while looking out for aurora activity, at http://www.swpc.noaa.org/Aurora.

"Further considerations are the weather at your location, and light pollution from city lights, full moon and so forth," the website says.

While the Hi-Line doesn't have to worry too much about light pollution — nothing a drive a few minutes out of town can't fix — the weather forecast for this weekend is predicting about a one in three chance of thunderstorms.

Stargazers have lucked out with the moon, which is currently a waning crescent, heading for a blacked out new moon on Wednesday. So that should not harm visibility too much.

It's unpredictable business, aurora-hunting, with uncertain weather and magnetic effects. But this won't be the last such storm for a while. In fact, there may be much more coming in the next year or two.

Solar activity goes through an 11-year cycle and is right now one year from the next peak.

Another flare, rated a 5.4 X-class flare, came at Earth in March, but mostly grazed the south pole.

This weekend's should be a head-on collision.