An eerie blood-red glow pulsed across the night sky above St. Louis on Nov. 5, 2001. It looked like a conflagration just over the horizon. In fact, it was the aurora borealis, the Northern Lights.
In this part of the Midwest, we aren’t treated to such a show very often. But on that special night seven years ago, people could watch the Northern Lights as far south as San Diego.

Last week, NASA researchers announced that they have determined what triggers this phenomenal phenomenon. It’s caused by a magnetic reconnection that takes place when the lines of a magnetic field 80,000 miles above the Earth suddenly snap into a new shape.
Determining what creates the lights is crucial to forecasting the geomagnetic storms that disrupt satellite communications and terrestrial power systems. Last week’s discovery was made possible by a brace of five NASA satellites orbiting the Earth.

Scientists long have known that the Northern Lights displays are more vivid after a period of solar flares. Those flares occur when stored energy is released suddenly from twisted magnetic fields above the sun. The flares, in turn, create a “solar wind” that deflects the magnetic fields around the Earth’s poles. When those fields snap back into place, we get the Northern Lights. What we saw in the sky over St. Louis in 2001 resulted from an especially large event called an “X-class solar flare.”

It’s comforting, we suppose, that scientists finally have solved one mystery of the Northern Lights. But not the mystery.
Anyone who ever has seen the northern sky pulse hell-fire red or ghostly green and wondered what strange forces are at play across the universe will tell you that. The mystery of Northern Lights won’t be solved by science, and it won’t be solved soon.

Photos of Northern Lights and Solar Flare by NASA.