WHY DON’T PLANETS TWINKLE ?

Whenever you enjoy the night sky, then you notice the stars, galxies, etc..

You notice the all the objects as stars. But actually they all are not stars, some of them are different objects then you think. I will tell about them in the end. 

To understand all that, we have to know the secret behind the twinkling of objects of night sky.

To understand that secret, first we have need to understand the Refraction of light.

What is Refraction of light ?

When ray of light passes from one medium to another, it deviates from its original path. This phenomenon is called Refraction of light.

Mediums are: 

Solid 

Liquid 

Gas or Air 

The path changes due to the different speed in different medium. The speed of light is Highest in Solid and Lowest in Gas.

Let's take a look at the different speed of light in different medium. 

Speed in: 

  Solids (glass)- 200000 Km/sec

Liquids (water)- 225000 Km/sec

       Gases (air)- 300000 Km/sec

To understanding the extend of bending, we have to first understand the refractive index.

What is Refractive Index ?

Refractive Index s the ratio of the Speed of light in the first medium to that in the second medium.

It is represented by the Greek letter mu. 

If you want to read more about it, then take a practical look on Youtube.

In simple way, we can say that Refraction is a deviation of light, due to the different speed of light in different mediums.

Now, we are able to understand the secret of twinkling of stars.

Let's take a look on that secret that secret.

Why Stars Twinkle ?

Earth’s atmosphere is in constant motion and the density of its numerous layers can vary rapidly. So the refraction (or bending) that a star’s light experiences as it propagates through the atmosphere is also constantly changing. 

.                                         Night Sky

It means that the apparent position and brightness of a star changes slightly from moment to moment. 

This makes the star appear to wobble or ‘twinkle’.

However, a star is so far away that it is just a point of light, whereas a planet, being so much closer, is a tiny disc of light.

 Although your eyes can’t resolve the disc unaided or naked, the extent of the planet on the sky is generally much larger than the size of the atmospheric variations which cause twinkling. 

Why I can't see planets Twinkling ?

So, although planets do actually twinkle to some extent, it is much less noticeable than it is for stars.

Yes, that stars likes objects are Planets. They are less noticeable in the night sky.

Did You Know ?

7.5 times light can go around the world in one second. It travels at blistering 3,00,000 km per second.

Conclusion

One word for this whole article is Refraction of Light.

Complete this article observe the night sky tonight. You will find some more interesting. 

And put questions on them and ask me in the comment.

Find Extra, To Become Extraordinary.