Auroras are a display of incredible beauty and are more commonly known as the Northern Lights (Aurora Borealis) and the Southern Lights (Aurora Australis).
They have always fascinated mankind and some of our ancestors believed that the “lights in the sky” served as paths which the souls of the dead traveled towards the gods. Others thought that the dancing colours were omens of great events, both good and evil.
The auroras at the Earth’s magnetic poles occur when highly charged particles from the solar wind interact with elements in the earth’s atmosphere. The charged particles are drawn towards the magnetic poles following lines of magnetic force generated by the earth’s core.
What fascinated me was the colourful display from the auroras and I never understood why and how the colours appeared. As a matter of fact the colour of the aurora depends on which atom of oxygen or nitrogen is struck in the atmosphere and at what altitude.
- Green - oxygen, up to 150 miles in altitude
- Red - oxygen, above 150 miles in altitude
- Blue - nitrogen, up to 60 miles in altitude
- Purple/violet - nitrogen, above 60 miles in altitude
The dancing of the auroras occurs because of the shifting of the magnetic and electrical forces reacting with one another.
Although auroras occur around the Arctic and Antarctic there are times when they move further south, usually during times when there are many sunspots. Since sunspots follow an 11-year cycle and they have an impact on auroras the next opportunity for seeing them outside their normal range is 2011 and 2012.
Auroras not only occur on Earth but have been spotted on Saturn and Jupiter as well. This phenomena is something everyone should see, myself included.
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