Explain giving reason why the sky appears blue to an observer from the surface of the Earth. What should the appearance of the sky be during the day for an astronaut staying in the international space station orbiting the Earth? State reason to justify your answer.
Answer:
The fine particles in the atmosphere scatter light of shorter wavelength (blue colour) more strongly than the light of longer wavelength (red colour). Therefore, the sky appears blue from the surface of the Earth.
For an astronaut the sky would appear dark because in space there is no atmosphere for scattering light.