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What are the Aurora Borealis?

The Aurora Borealis, also known as the Northern Lights.
The Aurora Borealis reflecting off a still lake.
Amazing pictures of the Aurora Borealis have been taken from the International Space Station.
Auroras are observed over Earth's magnetic poles.
During super solar flares, the aurora borealis can be seen from as far away as Boston, L1amRulz.
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  • Written By: Michael Anissimov
  • Edited By: Bronwyn Harris
  • Images By: Pilensphoto, Pilensphoto, Global Panorama, Mila Gligoric, James Thew
  • Last Modified Date: 30 September 2014
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The Aurora Borealis, also called the Northern Lights, are curtains of light created when fast electrons from the solar wind slam into the rarefied gas of the upper atmosphere. The mechanism of action is similar to the way electrons in a television generate specks of light when they impact the phosphor-coated inside of the screen. The physics of the phenomenon are complex, however, and not perfectly understood. The energy of certain types of aurora probably derives from a dynamo effect of the interplanetary (solar wind-caused) magnetic field against the Earth's magnetic field. This is similar to the way electricity can be generated by rotating a magnet within an electromagnetic coil.

The aurorae are green or faintly red, produced by re-emission from atmospheric oxygen. Atmospheric nitrogen sometimes produces very faint blue/violet aurorae. Some of the most magnificent pictures of the Aurora Borealis have been taken from the Space Shuttle or International Space Station, which views it from an angle impossible from the ground.

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The Aurora Borealis is most easily observed about 1,500 miles (2,400 km) from the Earth's magnetic poles. A southern variant also exists, called the Aurora Australis, but this is rarely observed because it mainly occurs in the oceans around Antarctica. The Earth's magnetic poles are located about 11° away from the geographical poles, and in the north, the magnetic pole is located just north of Canada, meaning the lights are easily observable from places like Fairbanks, Alaska. Rarely, during magnetic storms and coronal mass ejections (super solar-flares), the phenomenon becomes much more intense, and it can be visible as far south as Boston. In 1856, a coronal mass ejection produced aurorae so strong that a person could apparently read a book at night in New York using the light produced.

The Northern Lights have long been subjects of mythology and superstition. Scandinavians once thought they were produced by the reflections of huge schools of herring, while in Scotland, they were called the "merry dancers." Gold miners in Alaska believed they were reflections of the greatest mother lode. Until the advent of scientific satellites, many of the theories about the aurorae were very speculative, and even today, the understanding of researchers is not perfect, but it is steadily improving.

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orangey03
Post 8

I imagine that the people who lived hundreds of years ago were pretty scared and mesmerized by the Northern Lights. I know that if I walked outside and saw the sky dancing with brilliant colors, I would start praying for protection right away!

Even something so beautiful could be scary if you didn't know why it was happening. For such a large section of sky to light up like that, you would have to have a pretty major event.

Kristee
Post 7

@Oceana – As far as I know, they don't occur naturally. I have heard that they are given some kind of thin metallic coating, and this is what causes all the different colors to appear in one stone.

My grandmother told me that Aurora Borealis stones were really popular back in the fifties. She has a brooch made with them, and it is the only one I have ever seen. She said they were pretty expensive back in the day.

Oceana
Post 6

Has anyone here ever heard of Aurora Borealis stones? My friend has some earrings that are made with them, and they are gorgeous.

The stones have so many colors in them. I have no idea how these were made, and I wonder if they occur naturally.

DylanB
Post 5

@anon190830 – You saw them in the daytime? That is amazing!

I live in the deep South, so I doubt I will ever get the chance to see these lights. I imagine that they are the things childhood dreams are made of, though. I can just envision unicorns dancing around in the sky, encircled by a rainbow of moving colors.

anon190830
Post 4

the aurora borealis were seen in Cottage Grove, Oregon recently in the mid afternoon. It totally blew us all away knowing the atmospheric generation of the upper amostphere in the daytime at 3 p.m., and it is usually at night. it was the most beautiful of all the western hemisphere has seen in a while.

Sara84
Post 3

I think it is nice how there is an aurora borealis forecast now. Years ago, they did not have such a thing and I missed out on viewings. Now I can turn on the television and get information on the next coming event. I could watch these gorgeous lights a thousand times.

scifreak
Post 2

I remember seeing these beautiful lights as a child. I did not know they were called the aurora borealis lights. We just thought that they were very pretty. They also did seem to happen very often; it was like they were a rare event.

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