hey there!  welcome to the new episode of Curiosity! A series in which we will answer some of the questions that makes us all curious.   

A one of the natures most beautiful Displays. It's called Aurora Borealis or the Northern Lights. Despite the name "Northern Lights" this phenomenon can be seen at different places like Singapore , Honolulu but most commonly observed at arctic circle. Also the South Pole has it's own counterpart of Aurora Borealis , it's called Aurora Australis. Not only on Earth, this phenomenon can be also observed on other planets like , Jupiter , Saturn and Uranus. But what Exactly causes these ? Let's Find out.

Firstly, What are Northern Lights?

Northern lights are actually the bright dancing light created by the collision between electrically charged particles coming from the sun that enters the Earth's Atmosphere. These lights are mostly seen in the sky of magnetic poles (North and South Poles). In the North they are Known as Aurora borealis and In south they are known as Aurora Australis.

The lights might have shades of red , yellow, blue, violet but the most common colors are Green and Pink. Also these light might exist in many forms from patches of lights, arcs , ripples or shooting rays. These rays light up the whole sky with an eerie glow.

What Causes these dazzling light show?

These Northern Lights are actually caused because of our Sun. Our sun's about 4 billion  years old. A gigantic ball of hydrogen and other heavier gases fusing away in the space about 90 million miles away. The temperature of the sun above the surface reaches thousands of degrees. Collision of gaseous molecules are frequently very explosive. Free electrons and protons are thrown away in the space in the form of solar wind escaping through the holes in the magnetic fields. Because of this phenomenon great storms are created. These storms of charged particles are sent hurtling through the space and if the Earth is somehow in the path of this storm, our atmosphere and magnetic field react.

Fig: Formation of Aurora (Credits)

The atoms in the Earth's molecule gets excited when the storm strikes the atmosphere of Earth. This means, when a charged particle strikes the Earth's atmosphere, the Electrons move from their lower orbit to the higher orbit or moving away from the central nucleus. After this, the electron comes back to the lower energy state releasing light.

What gives the color of the Auroras?

Auroras are seen in many colors although shades of pink and green are the most common one.  Shades of blue , violet, red etc have been also reported, but what exactly gives them the color? 

It turns out, the most of the variation of the color is due to the presence of different gas particles in the space. The most common variant of color (Green) is produced by Oxygen just 60 miles above the Earth. Red auroras are produced by very high altitude oxygen , which is about 200 miles high , this one is quite rare. Blue Auroras are produced by Nitrogen gas.

Fig: Gases Forming different color of Auroras (Credits)

Best Places to watch Auroras?

They are mostly seen in the magnetic poles (North and south). Scientists have learned the southern and northern auroras occurs like a mirror image at the same time. Because of this phenomenon , the Northern lights are seen as far as New Orleans in the western Hemisphere. However the best place to watch these dazzling displays in North America are generally seen in the northwestern part of Canada. Some of the places are Nunavut, Yukon , Alaska and other northwest territories. Also these auroras can be seen in the southern tip of the Greenland and Iceland.

But the southerns auroras are not commonly seen at different places. They are generally concentrated in a circle  around Antarctic ocean and south Indian Ocean. 

Apart from this, the best places are Small communities in the North where where "light Pollution" is very less.

Today , The Auroras Don't tend to be mysterious as they were in the past. People travel thousands of miles to watch these magnificent dancing lights in the sky. This interaction of the sun and our atmosphere is a gift that we are blessed with. If you have never seen an Aurora , This needs to be added to your bucket list. 

 That's it for this Episode guys, Hope you enjoyed it. If you did, Upvote and comment your thoughts below. Thank you

Stay Curious.

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References Used:

[1]-http://earthsky.org/earth/what-causes-the-aurora-borealis-or-northern-lights

[2]- http://www.athropolis.com/arctic-facts/fact-nlights-causes.htm

[3]-https://phys.org/news/2015-01-northern.html

[4]-https://www.northernlightscentre.ca/northernlights.html
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