In areas near the north and south poles, you are able to see different coloured lights at night in the sky. They are called auroras (or aurorae). The northern lights are called aurora borealis while the southern lights are known as aurora australis.
I've known about these lights but never really got around to learning more about them until aurora australis was featured in the Disney movie, Eight Below. Since Christmas, Caitlin has been averaging a dozen views a day of this movie and has practically memorised all her favourite scenes and lines.
As usual, Wikipedia has been my most convenient source of information and it gives a good description and information on the origin of auroras and other details.