Name : Novira Chandisa

NIM :16013291

Faculty : Mathematic and natural science

English essay of the third presentation (UAS)

AURORA

Have you ever heard a beautiful phenomenon that happen in our earth pole ? Many

people think this phenomenon is a supranatural phenomenon, but now the scientic can

explain how can this magic phenomenon happen. This is a physic phenomenon. Not just can

explain by physic but also many astronom learn more about this. And a scientic named ....

ever try to make this amazing thing in his laboratory, he used terella as the small earth, make

a magnetic field around it, and emit the charged particles and releasing light. What

phenomenon is that? Ya that amazing light is Aurora. This aurora is one of the natural

miracle in our earth. This essay will inform you about the aurora, the folklore, the type of

aurora, how the mechanism and the colours of aurora.

Aurora is a natural light display in the sky particularly in the high latitude Arctic and

Antarctic region. Aurora is from latin word mean “sunrise” or the Roman Goddess of down.

It caused by the collision of energetic charged particles with atoms in the high latitude

atmosphere. Most aurora occurs in a band known as the auroral zone which is typically 3 to 6

degress wide in latitude. Aurora cannot been seen in day light. The aurora is just happen in

the earth pole. Aurora in the north pole call northern light or aurora borealis. Aurora in the

south pole call southern light or aurora australis.

There are a lot of folklore behind the aurora but the most famous folklore is this three

folklore. The first is the aurora folklore from europe in the middle ages. They said that the

nortern light is the breath of brave soldiers who gave their lives as they battled forever in the

skies for their king and country. The second folklore is from the original skandanavian or

Sammi. Sammi believed that the northern light have supranatural power to resolve conflict.

The sammi paint simbols in their magic drum. The third folklore is from norwegian folklore.

They believed that the northern light were the spirit of old maids dancing in the sky.

There are two type of aurora. The first is diffuse aurora. Diffuse aurora dribbles

constantly into the earth atmosphere from the plasma sheet of the solar wind. It is featureless

glow in the sky that may not be visible to the naked eye even in the dark night. The second

type is discrete aurora . Discrete aurora is the most intense aurora easily visible in the clear

sky. Discrete aurora have many shape like spiral, curls, folds etc.

Aurora mechanism. The first, the sun emits a continous stream of charged particles

called solar wind. The wind interacts with the magnetic field of the earth by constantly

bombarding it. The solar wind collides with the atoms and molecules in the upper

atmosphere. The collision between the solar wind and the earth ‘s magnetic field ionize the

atoms and molecules , releasing light.

The causes of aurora are charged particle, coronal mass ejection and coronal hole.

Charged particles emitted by the sun , travelling towards the earth at speeds ranging from

300-1000 km/s are the main cause. Coronal mass ejection is a abasic cause of aurora. Large

bubbles of hot plasma present in the hot corona ejected from it causes aurora. Coronal hole

are the cooler and less dense regions in the coronal. It cannot confine the hot gasses from the

sun and release it towards earth that may result into an aurora.

Now what cause the colours of aurora? The colours is from the charged particles from

sun that collide with atoms and molecules of the upper atmosphere. When the charged

particles collide with oxygen it can make the green and brownish-red colour. And when the

charged particles collide with the nitrogen, it can make the blue, red and purple colour. But it

depend on where and what matter collide with charged particles.

That are just a few information about this magic light ‘aurora’. The aurora is a natural

phenomenon that can explain by physic theory. Aurora cause by the charged particles from

the sun which send as a solar wind to our earth. And because of the collision of this particle

with the matter in upper atmosphere it make light ‘aurora’. Let’s study physic, its make us

know more about our earth and ourself.