I'm a bit confused by the coverage the Northern Lights are getting. According to AP:
Scientists think they have discovered the energy source of the spectacular color displays seen in the northern lights. New data from NASA's Themis mission, a quintet of satellites launched this winter, found the energy comes from a stream of charged particles from the sun flowing like a current through twisted bundles of magnetic fields connecting Earth's upper atmosphere to the sun.
I thought scientists always knew it. What's the 'discovery' then?
Ah, here's the follow-up:
Although researchers have suspected the existence of wound-up bundles of magnetic fields that provide energy for the auroras, the phenomenon was not confirmed until May, when the satellites became the first to map their structure some 40,000 miles above the Earth's surface.
I'm a little less ignorant now.