Aurora Australis

When you are below the 40th parallel the night skies are crisp and clear, unsullied by the glow of city lights. You can head out to the top of Mount Wellington or any remote peak or lookout and watch the amazing Aurora Australis light up the southern sky.

The night sky glows and undulates like an enormous lava lamp, or beams pan the sky like giant searchlights. The colours change from green to red or blue as the charged particles streaming from the sun are trapped by Earth’s magnetic field and flow towards the South Pole. The particles collide with gases in the upper atmosphere, causing these gases to glow. It is similar to electrons passing through the gases in a neon tube. Different gases cause the different colours: oxygen atoms give off red and green light; nitrogen molecules give blue and violet light.

Image courtesy of Shevill Mathers, Southern Cross Observatory, Tasmania