Why the Sky is blue (Scattering of Light)

Relate the blue sky to the preferential scattering of light in its atmosphere

In this section we look at:

- Why the Sky is blue
- Light Pollution
- Benefits & Drawbacks
- Earth Wavelengths
- Observatory Locations


  • The atmosphere is made up of Nitrogen, Oxygen and other gases such as Argon and Carbon Dioxide.
  • There is more atmosphere on the surface near the sea than on top of a very tall mountain. Gravity is stronger the nearer it is to the Earth's centre.
  • Atmosphere thins out the further it is from Earth to the point where it merges with space.