September 21, 2009.

Some real facts about the Northern Lights
(Aqsarniit)

The other day we talked about how the Arctic regions are favored for seeing the Northern Lights. The auroral oval is a permanent fixture of our planet's upper atmosphere, and those fortunate enough to live under or near it, see the aurora routinely even when the sun is "quiet".

Although solar storms called flares are responsible for many auroras, the ones we see during the quiet times have a different origin. They're caused by holes in the sun's corona or outer atmosphere. Powerful magnetic fields just like the ones around your refrigerator magnets but much, much stronger, envelop the sun and contain much of the strong wind of particles that would otherwise stream away into space. Remember it's these particles -- electrons and protons -- that speed their way to Earth and excite our polar atmosphere to glow in the form of aurorae.

You can see more here.