On 24 July 1999, the sun made this eruptive prominence (the Earth image was added for comparison). When something this gargantuan heads Earthward, it can whack power grids and communications satellites. It may also push the auroras away from the poles, delighting temperate-region lovers of the northern or southern lights.

Courtesy: NASA/SOHO

RIGHT:The northern lights whoop it up!

© Jan Curtis, The Aurora Page, Michigan Technological University.

Sun on fire
Posted 27 July 2000 Confess. You take it for granted, don't you? The sun, we mean. It rises in the east and sets in the west. Sure, you may slather yourself with sunblock on a hot day, but otherwise, you figure ol' Sol's gonna be same-ol', same-ol', right?

Not. It's a mistake to take the sun for granted and assume it will quietly warm our world with nary a hiccup. Fact is, the sun is about as stable as, well, a stable of nervous thoroughbreds. This star loves to horse around, now bucking like a bronco, then plodding like a lame dray horse. When the sun is active, it sends enormous storms of hot, electrically charged particles into space, ready to fire up the Northern lights -- or burn out communications satellites and fry electric power grids.

In 1989, six million people in the Northeast lost power due to currents induced by a solar storm. More recently, a communications satellite croaked when a current was induced in metallic components.

The sun enters a period of maximum activity every 11 years, and if you add 11 to 1989, you'll understand why solar storms are in the headlines in 2000. On July 14, the sun let out a massive burst of star-stuff that, fortunately, trotted our way without overturning too many wagons.

Still, there's no way of predicting the damage from the next kick from our local star.

Horse rays
The sun being a bit heavier than a draft horse, you can forget about halter-training this animal. But hay, since you measure the sun's enormous output not in horsepower but in gigatons of TNT, it makes a bale of sense to try to predict the star's antics.

Call us star-struck, but the current solar storms are fodder for a Why Files examination of the only star we'll ever need. Our training ride will take us to the best way to peer inside our star. Well pace past the science of the northern lights and see whether we'll ever be able to predict them -- or the destruction of power grids and satellite communications.

Let's face it, when five billion tons of hot star-stuff starts galloping our way at a million miles an hour -- we Why Filers are gonna grab our riding helmets and canter into the barn.