Mystic Lights of the Poles: The Auroras

The auroras, also known as the polar lights, are found at the Arctic and the Antarctic regions of Earth. These lights are seen in the sky only near the high-latitude polar regions of Earth. Auroras are formed because of changes in the magnetosphere.

The magnetosphere is a region of charged particles around Earth. Charged particles such as protons and electrons are found in the magnetosphere. This region is affected by the magnetic field of Earth. Charged particles coming from the Sun, called solar wind, disturb the Earth’s magnetosphere. Because of solar wind, the paths of the charged particles are changed. These particles are shifted to the upper atmosphere of Earth. Thus, particles of the upper atmosphere are ionized and excited so that light of different colors and patterns is seen. To get the idea, imagine punching a pillow hard. If the punch is hard enough, the pillow casing will absorb the force and may break. Then the cotton stuffed inside will come out. Similarly, when these charged particles hit the particles in the upper atmosphere (the punch), the electrons (pillow casing) absorb the energy of the hit. Then light is emitted, like the stuffed cotton. The auroras may be seen as patterns of curtains, rays, spirals, or flickers across the sky. The pattern of auroras usually depends on the speed of the charged particles in the atmosphere.

In the north, this effect is called the aurora borealis or the northern lights, whereas in the south, it is called aurora australis or the southern lights. The words “borealis” and “australis” come from the names of old Roman gods of the north wind and the south wind.

Most auroras are seen in a band called the auroral zone. This band is usually 3° to 6° wide in latitude and found 10° and 20° in longitude from the poles of Earth. A region where the auroras are currently seen is called the auroral oval. Auroras are not a constant effect but are known to change with time.

The northern lights may be seen from the regions of Alaska, the Canadian Territories, Iceland, Greenland, Norway, Sweden, Finland, and Russia. In rare cases, the northern lights may also be seen in Estonia, Latvia, Lithuania, Scotland, Ireland, Denmark, and northern regions of the United States. Apart from the Antarctic region, the southern lights may be seen from the countries of Chile, Argentina, South Africa, New Zealand, and Australia.

Want to see the effect of the northern lights? Watch this video showing the northern lights in Bartlett Cove, Glacier Bay National Park, Alaska!