According to the National Oceanic and Atmospheric Administration, or NOAA, plasma from the sun's atmosphere hurtles highly charged protons and electrons toward the Earth in blasts of solar wind. The particles travel along magnetic field lines, which work like magnets and converge toward the north and south magnetic poles. In the process, the particles excite, or energize, oxygen and nitrogen atoms. As the atoms relax, they release their excess energy as light -- the aurora -- in ovals that center around the poles.
NOAA notes that there's almost always an aurora in the skies around the poles even though they're not always visible to spectators. Aurora activity picks up during solar storms because the storms intensify the solar winds that carry the charged proton and electron particles.
The Southern Lights are visible only from Antarctica, at the South Pole, with any frequency. However, when solar-storm activity is high, the oval around the pole grows and extends farther away from the South Pole, toward the equator. At these times, the Lights may be visible from a wider geographic area, depending on which land masses lie below the oval. However, according to the University of California's Exploratorium, this happens just once every few years to once in a decade.
Although the only realistic opportunity to view Aurora Australis requires a trip to Antarctica, it isn't even visible there from October through February, as the continent experiences 24-hour sunlight during those months. If you're hoping to get a glimpse of it north of the South Pole, NOAA has some suggestions. First, it recommends checking the aurora's current size and shape on the NOAA Weather Prediction Center's aurora website to see if it is visible from your location. This will most likely be during periods of maximum solar cycle activity. If it is visible, watch the sky between 10 p.m. and 2 a.m. A clear, moonless night during mid-winter is best. As of March 2011, NOAA anticipates that solar activity for the current cycle will peak in 2012 and 2013.
