The Northern Lights by Anaïs Lescher & Juliette Rascalou

What are the Northern Lights?

There is a very beautiful phenomenon that all humans should see. It comes with many legends: our ancestors thought that only God could create such a sight. Some of those myths are very poetic but all these stories have a scientific explanation! So we're just going to tell you how it works. From now on you will have something to impress your friends!

Northern lights are formed when particules from the Sun collide with the neutral atoms of the atmosphere. Don't worry it's not as complicated as it sounds.

Sometimes in the solar corona, protons and electrons are ejected and move too fast to be kept by the Sun's gravity. That's as if the Sun removes his jumper. This plasma moves away from the Sun and forms a solar wind.

Earth has its own shield to protect itself against this solar wind : the magnetosphere. But the particles are sly! They have the possibility to continue their journey towards the atmosphere.

When the Sun ejects a very massive ball of plasma in the solar wind, it hits the Earth so violently that it overcomes the magnetosphere and creates a magnetic storm.

The magnetosphere is stressed and folds up like an overstretched rubber band. When this rubber band is retracted, the particles are cast to the poles.

Protons and electrons have finally reached their destination and meet new friends! When they meet oxygen and nitrogen atoms, these are excited and produce photons. This creates beautiful northern lights!

 

 

In this way, very little particles have inspired a lot of legends throughout time...

To see:

The Northern Lights in Scotland : https://www.youtube.com/watch?v=fVsONlc3OUY

The Northern Lights in France : http://www.ouest-france.fr/aurore-boreale-sublime-spectacle-dans-le-pas-de-calais-et-en-vendee-3263115