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What is the Science Behind the Aurora or Northern Lights?

Updated: Mar 29, 2021

We look at the night sky and see a myriad of dancing lights. Auroras have been attracting many since the dawn of time. I have been assuming there has to be a science behind this majestic and beautiful phenomena. I couldn’t resist the curiosity and now have an answer to the dazzling lights. What causes the northern lights? Is it magic? An optical illusion? Technology? Or science? Well, there’s a vast world of luminescence waiting to amaze you!

What is the Science Behind the Aurora or Northern Lights?


North, the South Pole, and arctic zones are regions the beauty of the Aurora is visible. Aurora borealis or the northern lights is the name given in the north pole. In the south, these magnificent lights are referred to as the aurora australis or the southern lights. What makes it happen? Surprisingly, the sun powers the aurora (even though they are visible at night)!


What Causes Northern Lights or Aurora?



Notably, the sun brings us warm summer days, but the sun also gives us chunks of energy as small particles. We never notice the tiny particles emitted by the sun or its energy because of the earth’s magnetic field. The amount of energy and light particles the sun provides varies each time. In our solar system, there are streaming solar winds and solar storms. There is a specific solar storm named the coronal mass ejection. Coronal mass ejection is the gigantic bubble of electrified gas ejected by the sun that can travel through space at high speeds. When the earth is in the storm path then a few of the energy and particles travel down the earth's magnetic field lines. The electrified gas or plasma released from the sun's corona interacts with the atoms and molecules in the earth's atmosphere forming a beautiful light spectrum in the sky.


How Does The Atom Light Up in Nothern Lights or Aurora?


As we know an atom consists of a central nucleus. Electrons circles around the nucleus in an orbit. When the charged particles strike the atoms in Earth’s atmosphere, the electrons move to a higher-energy orbit. Which means the electrons move farther away from the nucleus. Later the electrons move back to a lower-energy orbit. During this process, the electrons release particles of a photon of light.


Do Northern Lights appear in different colors?


Do Northern Lights appear in different colors? The color depends on the gases which are excited by the electrons. The color also depends on the amount of energy exchange between the electrons. The following shows which gas emits which color.

  • Oxygen=Greenish-Yellow or Red

  • Nitrogen=Blue

  • Nitrogen & Oxygen=Ultraviolet


The nitrogen and oxygen ultraviolet light are only visible through specialized cameras on satellites. NASA imager has captured titanic aurora on Magnetopause-to-Aurora Global Exploration (IMAGE) spacecraft. The world of light, invisible to human eyes were beautifully captured by NASA's far-ultraviolet imager. The camera's ability to capture invisible Aurora with ultraviolet wavelengths has fascinated scientists at the University of California, Berkley. These images sent every two minutes by the far-ultraviolet imager from polar regions are used by the scientists at Berkley to further understand the evolution of Aurora or Northern Lights.


Why Does The Aurora Take Different Shapes?


Believe it or not, scientists are still finding the answer to this question. They have now found the Aurora or Northern Lights shape depends on w the electrons in the magnetosphere. It also depends on what caused the electrons to precipitate into the atmosphere. Surprisingly, many shapes appear in a single night. Though no two auroras are the same. We have named a few common ones.

  • Curtains

  • Arcs

  • Bands

  • Rays

  • Coronae

  • Patches


Curtains

This beautiful aurora is not rare. Curtains take a wavy, hanging in mid-air appearance. As you guessed they look very similar to an everyday curtain. In historic times curtains were referred to as drapes or draperies.

Arcs

This aurora is a simple beauty. It is a curve stretching thousands of kilometers horizontally and vertically. Unusually, they are only a few kilometers thick. Auroras change shape in a single night. Displays frequently start with an arc.

Bands

A band is related to an arc, for its close appearance and form. Its only difference is its wavy border (unlike the smooth border in Arcs). Bands have curved, twisting, and turning characteristics which makes them unique.

Rays

Rays are known for their famous luminosity. Rays have pillars that stretch vertically. A rayed structure is visible with other shapes, such as the arc or band. If you are lucky enough, this auroras can be more active as it moves!

Coronae

I think these are the most spectacular shape an aurora can take. This shape is named after the crown. A corona is described as myriads of rays connected to the sky above (much like a starburst formation). These shapes only happen if there is a strong overhead activity.

Patches

This shape, as you guessed it appears in patches. This aurora may not glow as much as other auroras. This aurora is not as common as other auroras. The way this shape varies from the others. Electrons are scattered in the atmosphere by a plasma wave known as a whistler.


Do Auroras Happen on Other Planets?


Well, the answer is yes! Other planets do experience auroras! The planets Jupiter, Saturn, Uranus, Neptune, Mars, and Venus all have auroras (other than Earth). Mars and Venus produce their auroras very differently than Earth because they don’t have a magnetic field. On Mars, the auroras take place near a magnetized rock. On Venus, it is believed that auroras occur because of their magnetotail. The gas giants all produce auroras the same way the Earth does.


Is it possible to see Aurora or Northern lights in the naked eye?


Yes, You sure can see Northern lights in the naked eye.


Is Aurora or Northern Lights visible in the Southern Hemisphere?


Yes, Northern lights are visible in the south pole and the north pole.


Does Aurora or Northern Lights affect the Earth's atmosphere or environment?


Aurora causes ionization in the atmosphere that prevents radio wave distribution. This ionization happens only a few kilometers closer to the Earth's surface.


Auroras or Nothern Lights are a majestic beauty. Scientists are still figuring out the mysteries of the aurora. Satellites were launched to further study Aurora's evolution and its physics. This light display changes the shape and colors of the night sky into a beautiful painting. Comment below if you have ever seen an aurora and its experience! Until next time. Cheerio!

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1 Comment


Tom Cashman
Tom Cashman
Jul 25, 2023

So beautiful! I really want to see the Northern Lights in person one day, maybe a trip to Iceland!

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