Science - Physics and forces - Rayleigh scattering
Why does the sky usually appear blue during the day?
Correct!
Sunlight contains many colors. When it enters Earth’s atmosphere, air molecules scatter the light. Shorter-wavelength light, especially blue light, is scattered more strongly than longer-wavelength red light. Blue light therefore reaches us from many directions and the sky appears blue. This is called Rayleigh scattering. At sunrise and sunset, light travels through more atmosphere, so more red and orange light reaches our eyes.
Source: National Weather Service
