Aurora above Australia
As appeared on Astronomy Picture of the Day the Southern Lights or Aurora Australis is photographed above the southern coast of Australia near Melbourne. The Milky Way is visible over the southeast in the constellations Scorpius (at the horizon), Ara, Norma, Centaurus, and Crux (the Southern Cross, at top). On the right two satellite companions of our Milky Way are visible, the Large and Small Magellanic Clouds, each a galaxy of its own but much smaller than the Milky Way. Aurora is caused by the solar wind; energetic charged particles originated from the Sun. The Earth’s magnetic field traps these particles and many of them travel toward our planet magnetic poles where they collide the molecules in the atmosphere and cause energy releases in the form of auroras appearing in large circles around the poles. But when stronger streams of particles, made by solar eruptions, reach the Earth the aurora circle spread to the lower latitudes such as the southern Australia.