T he sky isn't just blue by chance. I t takes all the colors of the rainbow for us to see it that way. I t happens because of something called the Rayleigh effect, or Rayleigh scattering ...

Rainbows happen when sunlight passes through raindrops in the sky. When this happens, light becomes separated into a rainbow of colors—red, orange, yellow, green, blue, indigo (blue-violet), and ...

If there were no scattering, the sky would be dark like it is on the moon, which does not have an atmosphere. Light at the blue end of the rainbow is scattered more efficiently than the other colours.