How is the aurora formed?

Aurora is a large-scale discharge process around the earth.

Charged particles from the sun arrive near the earth, and the earth's magnetic field forces some of them to concentrate along the magnetic field lines to the North and South poles. When they enter the polar upper atmosphere, they collide and excite with atoms and molecules in the atmosphere, producing light and forming aurora.

According to the data sent back by NASA, scientists found that charged particles released by the sun flew to the earth like a stream of air, and when they hit the magnetic field over the North Pole, they formed some distorted magnetic fields. The energy of charged particles is released in an instant in the form of bright and dazzling northern lights, and the reason why the aurora of the earth is mainly red and green is because the nitrogen atoms and oxygen atoms in the thermal stratification are shattered by electrons, giving off red and green light respectively.

Basic classification of aurora

Aurora can be divided into two types according to its nature: diffuse aurora and discrete aurora. Even in the dark sky, the diffuse aurora may still be invisible to the naked eye, emitting a shimmer and shape that permeates the sky, but it defines the scope of the aurora belt.

1. According to the morphological classification of aurora, it can be divided into uniform light arc aurora, ray beam aurora, ray light arc aurora, curtain aurora, aurora corona and so on.

2. According to the electromagnetic wave band observed by aurora, it can be divided into optical aurora and radio aurora.

3. According to the types of laser-excited particles, they can be divided into electron aurora and proton aurora.

4. According to the occurrence area of aurora, it can be divided into polar cover aurora, aurora belt aurora, mid-latitude aurora red arc and so on.

The above contents refer to Baidu Encyclopedia-Aurora