Eli5 what causes aurora borealis?


Eli5 what causes aurora borealis?

In: 6


It’s a celestial fluorescent light or neon sign.

The magnetic field of the Earth traps a plasma which is disturbed by the solar wind causing large current flows in the upper atmosphere. This ionizes and excites the molecules which give off light just like in a fluorescent or neon tube.

Different molecules give off a different spectrum of light when excited. The colors are generally determined by the predominant gases present at the different layers in the atmosphere. Different gasses produce the different colors.

Charged particles like elcectrons are constantly shooting off of the sun. Most of them are blocked by the Earth’s magnetic field. Near our north and south poles, the Earth’s magnetic field is oriented in such a way that it doesn’t block those particles very well. When the particles collide with atoms in our atmosphere, the atoms get excited and emit colorful light.