Aurora Borealis is also known as the Northern Lights, and is a marvelous feature of nature. The sky is lit with colors which are moving to and fro in a pattern. Sometimes it seems the sky is closed with a big dome, like a church. Sometimes whole batches of light are sweeping over the sky. It is absolutely breathtaking. What is the Aurora Borealis? What causes this fantastic display of colors and light?
The name Aurora Borealis comes from Greek. Aurora means dawn, and Borealis was the name of the northern wind. So literally it means the dawn from the north. The interesting thing is that the physics of these Northern Lights is not wholly understood. Basically they occur when electrons from the solar winds hit the upper atmosphere. It is something similar to the way televisions and neon lights work, with electrons and gases.
In the same way as the earth, the sun also has a kind of atmosphere and magnetic field surrounding it. Particles (electrons and protons) from the sun are constantly being slung towards the earth because of the magnetic field. This is called solar wind, the combination of particles and magnetic field.
Now, the earth has a magnetic field, too. The magnetic poles, as they are called, are in the middle of the earth, like if giant rods were put through the earth. From there the magnetic field circulates outwards. This means that the magnetic field is the strongest at the south and north parts of the earth, less strong around the equator. This is the reason we need to travel north to see these lights! Or south, where the lights are called Aurora Austarlis, the dawn from the south!
So when the particles from the solar wind are coming with enormous speed, hitting the magnetic field of the earth, they get pushed down to the earth’s upper atmosphere, the ionosphere. Here, the electrons collide with gas atoms, causing a great release of energy and light! The Northern Lights, Aurora Borealis, are seen. Usually the whole spectrum of colors can be seen.
People pay a lot of money to travel to places where it is possible to see the Aurora Borealis. The best place to go is Northern Norway, although the lights can also be seen in other places. Norway has a fairly mild winter climate, has a high concentration of Northern Lights, and is easily accessible. It is well worth the money. To see nature in this dynamic display of energy and light is something that will stay with you for a life-time!
