The polar lights are natural phenomena that happen in both hemispheres; Northern light (Aurora borealis) in the northern hemisphere, and Southern light (Aurora australis) in the southern hemisphere.
The physics behind the polar lights were explained by Kristian Birkeland, professor at the Univestiry of Kristiania (Oslo). He designed an experiment where he demonstrated the process in the years 1900-1913.
The sun emits clouds (streams) of particles, also called solar winds, towards the Earth. This "cloud" is called "Coronal Mass Ejection" or CME. After 2 to 3 days travelling towards the Earth, the solar winds collide with the Earth's magnetic field. This collision causes the cloud of particles to travel towards the poles, where the solar winds will interact with the particles in the atmosphere.
Here comes the magic: when the solar wind particles interact with the particles in our atmosphere, there is an energy exchange due to the clash between them, and the released energy will result in a tiny dot of light. When a significant amount of particles is lit up at the same time, we will be able to see a polar light.
There are several other factors that influence the possibilities of seeing northern lights. Apart of the phenomenon to be happening, we need to have clear skies (northern lights happen above the clouds), avoid light pollution, and have a proper view of the sky.
As a general rule, the northern lights are dim lights on the sky that first look like clouds, and then become stronger. They may get bright colors, or can stay as a greenish gloom: it is a natural phenomenon and, therefore, it is never the same as the previous ones.
See the next video for a great explanation from the University of Oslo:
The Aurora Borealis from Per Byhring on Vimeo.
There are several other factors that influence the possibilities of seeing northern lights. Apart of the phenomenon to be happening, we need to have clear skies (northern lights happen above the clouds), avoid light pollution, and have a proper view of the sky.
As a general rule, the northern lights are dim lights on the sky that first look like clouds, and then become stronger. They may get bright colors, or can stay as a greenish gloom: it is a natural phenomenon and, therefore, it is never the same as the previous ones.
See the next video for a great explanation from the University of Oslo:
The Aurora Borealis from Per Byhring on Vimeo.
Great Blog. Thanks for sharing what are northern lights and how they formed. Alaska is one of the best place to see beautiful northern lights. So, plan your Northern lights trip to Alaska.
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