How are the Northern Lights formed?
How are the Northern Lights formed?
The Northern Lights, also known as the aurora borealis, are a major tourist attraction and a once in a lifetime experience for many people. However, have you ever stopped to wonder about the science behind it all? Although it might appear a pretty light show to some people, to others it’s much more. In this post I am going to explain the science behind this planetary aurora and the beautiful complexities that surround it, in hopefully the simplest and easiest way possible.
Solar Wind:
Solar Wind is the flow of charged particles through our solar system, that have originated from our sun. This solar wind is the cause of planetary auroras such as the Northern Lights. When these charged particles come into contact with the Earth’s magnetosphere, the result can be pretty impressive.
Earth’s magnetosphere:
A planet’s magnetosphere is caused by activity in its core, mostly the induction of currents. The magnetosphere extends in a circle from pole to pole, the pressure from the solar wind extending its tail far beyond the planet. When these charged partic
les come into contact with Earth’s magnetosphere, they run along the magnetic field lines because this is the point with the least resistance. This continues to happen until the particles are destroyed by colliding with other particles, this usually takes place towards the poles. This is because this is where the magnetic field lines are concentrated and the atmosphere is thicker.
These collisions with the particles in the atmosphere result with the particles being ionized. Photons are then released. The color of the light that will be emitted is dependent on the atmospheric particle itself. For example, oxygen atoms gives off a green light and nitrogen atoms emit blue or red light. These are the different colors we see when we observe the Northern Lights.
The Northern Lights:
Planetary auroras do not often take place near the equator, although it is not unheard of. Sometimes the inte
nsity of the solar wind is strong enough to force the aurora away from the poles, the place these remarkable light shows are predominately found. The solar wind is normally attracted to the poles because they have the highest concentration of magnetic field lines, as mentioned previously.
As these charged particles continue to interact with Earth’s atmosphere, more and more light is produced. This light is often found in the form of sweeping waves or huge bands of light. This is what we can see from Earth.
Thank you for reading. If you have any questions or requests, don’t hesitate to ask in the comments!
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