How come I've never heard about the Southern Lights? I've heard of the Northern Lights.
-- Jay, In the Dark
As usual, you haven't been paying attention. Northern Lights = Aurora Borealis. Southern Lights = Aurora Australis. When it comes to the other hemisphere, we're more interested in stuff like Kylie Minogue. Both sky-light phemonena come from the solar wind rubbing against our big ol' magnetic field. As wind particles are excited, then unexcited, they emit visible (and invisible) radiation that we see as huge, undulating curtains of colored light. Way, way more interesting than Kylie Minogue.