AURORA AUSTRALIS

12/1/2017

December 1 is Antarctic Day, an appropriate time to publish a blog on Aurora Australis.

PRETTY LIGHTS
Most of us enjoy seeing the beautiful and festive lights during the Holiday Season. They are cheerful and contribute to the joy of the season. They use up a great deal of electrical energy, but we love them and refuse to give them up.

But one of the most spectacular displays of lights is a natural phenomenon and doesn't add anything to the electric bill—if you live in one of the auroral zones of the world.

www.backpackerguide.nz. Mawson

AURORAS
An aurora is a natural light display in the sky. Nature's light show. The word comes from the Latin word meaning sunrise, also the name of the Roman goddess of dawn. The aurora borealis (northern lights) were named after the goddess Aurora and the Greek name given to the north wind (Boreas) by Galileo in 1619. I wonder if Galileo actually traveled to the north to see them, but didn't go into it. Later, I found a reference to them being named by a French Astronomer in the 1500s.

After reading several incredibly technical descriptions of what causes them, I settled on the simplest from Wikipedia which says auroras are "...caused by the collision of solar wind and magnetospheric charged particles with the high altitude atmosphere (thermosphere." They appear as curtains, sheets of light, or as a diffuse glow.

AURORA AUSTRALIS
I think I will name my next heroine after the southern lights: Aurora Australis. The aurora australis are seen near the south pole in the southern hemisphere. The word australis is the Greek word for south.
They are strongest in an oval around the south magnetic pole and not often seen in populated areas, although I found photos taken in Tasmania and Australia. Increased solar activity sometimes increases visibility from more distant locations.

The best time to see them is in the winter (which is summer in the northern hemisphere). The colors depend on what gas is present in the atmosphere:

1) oxygen emissions = Green or brownish-red
2) nitrogen emissions = blue or red.

Photo: Aurora Australis taken September 11, 2005 by NASA's IMAGE satellite

Colors and the forms themselves can change within seconds or glow without change for hours.

1st Row: Mawson Station Antarctica Scott Allerton Photography Amundson-Scott Station South Pole
Photo: Lydia Jean Dobromilsky           Photo: Hunter Davis

2nd Row: Ararat, Victoria-ABC                 Sophie Fazackerly on instagram
Facebook: Bec Potter