In Islam:
7 skies are explained in different religious book and their number are mentioned in Holy book Quran.
The 1st sky's Arabic name is "Rafi" .Yes, it is our beautiful sky and it is made of vapors that defines atmosphere in our planet. We all know that, it is filled with plenty of stars and million of million galaxies.If we explain its structure, then several authentic religious Islamic books revels that is it is just like frozen ocean wave.
The 2nd sky is above the 1st one and that is "Qazoom"(Arabic name) .It is made of Copper and harder then the lower sky. Its structure is like that it is very much in its solid form.
The 3rd sky is named as " Madoon"(Arabic Name).It is just like the 2nd sky from color point of view but it is a separate sky with it own separate characteristics.It is like copper but much harder then previous one.
Arfaloon(Arabic Name) is the 4th sky.It is made of silver and very very beautiful sky.
Fifthe sky is "Heyoon"(Arabic Name).It is made of gold.
The 6th sky's Arabic Name is "Uroos".It is just like green ruby. Just imagine how wonderful it is.
Last but not the least sky is 7th sky.Its Arabic name is "Ajma".It is made of white pearl.It is just like a heaven.
To find out more click the link below :https://youtu.be/-qnsc5KbDAg
Modern Science:
Fails to explain other six skies above our sky. Many books,articles,research paper and blogs explains only 1st sky characteristics. I acknowledge the work of Prof. Mauricio ACEVEDO in regard of our sky that is why using his blog notes here to explain his point of view regarding only sky.
His blog note is as follows:
"ASTRONOMY NOTES - Prof. Mauricio ACEVEDO
The colors of the sky:
If you look at the sky, you will see that at different times of the day, the sky has different colors. For example, at sunrise and sunset, we have the morning and evening twilight, in which the predominant colors are the shades of red, yellow and orange and also some violet tones.
While after sunrise and spend the sunset, the predominant color is blue and light blue, depending on its shades of the geographical point where you are (if it is on the plain or mountain).
The physical phenomena involved in these changes are absorption and diffusion.
Absorption: acts on the long waves that make up light according to the wave theory that considers light as electromagnetic waves. The angle of incidence of the solar rays when crossing the atmosphere, have a greater thickness of this in front and therefore impurities such as gases and suspended dust, accentuate the effects of absorption.
The diffusion: acts on the short waves of light that result in the colors around the blue, and whose penetration is greater given that the angle of incidence approaches the vertical, although close to twilight the angle seems to be far from the vertical ."
