why is the sky blue? – I'm a Scientist 25/26

Question: why is the sky blue?
- Keywords:
  atmosphere,
  colour,
  sky
Asked by cave1norm53 to annaparsecwallis, Olivia, Martin M, Kathy Wu, Eliza K, dimplepathania on 8 Apr 2026. This question was also asked by eked1norm53.
- Martin McCoustra answered on 8 Apr 2026:
  
  This is due to scattering of light in the atmosphere. Short wavelengths like blue are scattered more making the sky normally blue. However, as the Sun sets, the light we see goes through more atmosphere and more and more longer wavelength light is scattered until the sky appears red.

Question: why is the sky blue?