The sky has no color of its own. It appears blue because of the scattering of light. Know why it appears red at sunrise and black in space?
Why Is The Sky Blue: Whenever we look upward during the day, the sky looks blue. The interesting thing is that the sky has no color of its own. It appears blue to us because sunlight scatters in a special way while passing through the Earth’s atmosphere. Meaning, the blue color of the sky is visible due to light and air molecules.
Why does the sky appear blue?
Small particles of air scatter more blue light. When sunlight enters the Earth’s atmosphere, it collides with air molecules and very small particles. During this period, blue and violet lights scatter the most because their wavelength is shorter. Our eyes can see blue light more easily than violet. Also, there is sufficient amount of blue color in sunlight. That’s why the entire sky appears blue to us. This process is called Rayleigh Scattering.
Then why doesn’t the sky look purple?
According to science, purple color also scatters a lot. But our eyes are more sensitive to blue color. In addition, ozone in the upper atmosphere also absorbs or absorbs some violet light. That’s why we see the sky blue.
Why does the sky turn red at sunrise and sunset?
In the morning and evening, sunlight has to travel a longer path through the Earth’s atmosphere. During this time, blue light gets scattered more along the way and mainly red, orange and yellow light reaches our eyes. Therefore the sky appears red or orange at sunrise and sunset.
Why does the sky appear black in space?
There is no atmosphere in space like Earth. There are no air molecules there that can scatter sunlight. For this reason, astronauts see the sky black even during the day.
Some interesting statistics about space
- Rayleigh Scattering was discovered in 1871.
- Blue light scatters about 10 times more than red light. For this reason blue color is most visible during the day.
- The sky looks dark on the moon. There is no atmosphere on the Moon, so the sky there appears black even during the day.
- The color of the sky can change due to pollution. As the amount of dust, smoke and pollution increases, the sky may appear whiter, hazy or faded, because larger particles scatter light differently.
- Our eyes are more sensitive to blue color. The sensitivity of the human eye is also a reason why we see the blue sky more clearly.
(Content Sources: NASA, National Oceanic and Atmospheric Administration, Encyclopedia Britannica, European Space Agency, American Physical Society)