Question

Why does the sky appear dark instead of blue to an astronaut?

Answer 1

Explanation:

1. When light travels from one medium to another, a portion of it is absorbed by the medium's particles, followed by its subsequent emission in a specific direction. This phenomenon is termed as the scattering of light. The intensity of scattered light depends on the size of the particles and the wavelength of the light.
2. Light can be examined entirely from its source. When light passes from one medium to any other medium say air, a glass of water then a part of the light is absorbed by particles of the medium preceded by its subsequent radiation in a particular direction.
3. Shorter wavelength and high frequency scatter more due to the waviness of the line and its intersection with a particle. The wavier the line, the more the chances of it intersecting with a particle.
4. On the other hand, longer wavelengths have low frequency, they are straighter and the chances of colliding with the particle are less so the chances are less.
5. Because there is no atmosphere in space, light does not scatter into its constituent hues, which is why an astronaut in space sees the sky as dark rather than blue.

Thus, the sky appears dark instead of blue to an astronaut, as a scattering of light does not take place outside the Earth's atmosphere.