What Are The Northern Lights?

Most of us have heard the most magnificent and beautiful things about it, but only a small amount of people have seen it in real life. I am talking about the Northern Lights, also known as Aurora Borealis. It appears in a clear night sky as swirling rivers or curtains of greenish-blue light. Some people also describe it as vibrant colours glitter or dancing neon-light but what is this breathtaking nature phenomena exactly and why does it appear?

What causes the Northern Lights?

1. The main source of the Northern Lights is our biggest star, the sun. The sun produces its energy by smashing hydrogen atoms into its core. This happens under such high temperatures and pressure that the hydrogen atoms fuse into helium atoms. This process is known as nuclear fusion. Because of this process, the sun is able to create a huge amount of energy. The high temperatures and pressure causes a strong magnetic field. Sometimes the magnetic field is forced outwards (towards the surfaces of the sun). That is a result of the high pressure that cause the magnetic lines to meet with other magnetic lines. The sun’s gravity can not hold it and some charged particles are flung off into space and travel in every direction. Those particles are traveling with a speed of 300-500 km per second, therefore they can travel on a huge distance. This is called the solar wind.

2. Those solar winds can be very dangerous, but the earth has his own protection, the earth’s magnetic field. Only 2% of charged particles that reach the earth, leak through the earth’s magnetic field.

3. When these charged particles made their way into the earth’s atmosphere, they collide with oxygen and nitrogen atoms. During these collision the energy from the charged particles travel to the earth’s oxygen and nitrogen atoms. That causes to raise those atom’s energies and therefore exciting them. When an atom gets excited its electron moves into an orbit further away from the nucleus. The excited atoms need to release their energy to calm them self down. The electron moves back to its original place. During this process the atoms release a proton (particles of light). The light they give out is what we see as the Northern Lights.


When and where can you see the Northern Lights?

The Northern Lights are best seen in winter. The days are the shortest in winter. That means the nights are longer and darker and that is a favourable factor if you want to see the Northern Lights. It is also important that the moon emits as little light as possible. When the moon emits a lot of light, the sky is dark blue instead of almost black and therefore the contrast between the Northern Lights and the sky is smaller. The process of the formation of the Northern Lights can take place at any time of the day, but you can not see it during the day. It is therefore better if it is not a full moon, but during a full moon you can still see the Northern Lights in some cases (the chance is a lot smaller). The Northern Lights are most often seen at the extreme points of the earth, so the North Pole and the South Pole. This is because there are weak spots in the earth’s magnetic field, what makes it easier for the charged particles to get into the Earth’s atmosphere. Many people think that temperature is also a factor, but it is not. You can see the Northern Lights when it is 30 degrees Celsius. However, in places in the world where it gets so hot, it doesn’t get dark enough at night and there are also fewer weak spots in the earth’s magnetic field because those places are most of the time around the equator.

Why does the Northern Lights appears as lines?

The Northern Lights typically appear as vast curtains or waves of light following a specific line. This is a result of the lines from the earth’s magnetic field. The atoms that release a proton follow those lines.

Why does the Northern Lights appears in different colours?

When an atom gets excited, its electron moves into an orbit further away from the nucleus, then the atom contains energy. The excited atoms need to release their energy to calm them self down. The electron moves back to its original place. During this process the atoms release a proton (particles of light) and this proton contains the same amount of energy that cause the electron to move into an orbit further away. Every kind of atoms has its own orbits, therefore every kind of atom needs a different amount of energy to cause an electron to move into an orbit further away from the nucleus. That means that every kind of atoms release a proton with a different amount of energy. The colour of the proton depends on his energy. The earth’s atmosphere is made up of different atoms, therefore the Northern Lights appears in different colours. The most common colour seen in the Northern Lights is green, that is because when the solar wind hits an atom in the atmosphere most of them are oxygen atoms and the protons that are released by oxygen have the amount of energy that causes the colour green.

Now, that we know how the Northern Lights are formed, it may spoil the beauty for you, but believe me there’s an even greater beauty in understanding the science behind one of nature’s most breathtaking performances. So, if you’re ever lucky enough to experience the Northern Lights for yourself, just take a moment to contemplate on how truly marvellous and impressive the universe is. After enjoying and admiring the Northern Lights, you have to make some beautiful pictures!

September 21, 2022

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