Kabir Bakie, Creative Commons

HyperPhysics: Blue Sky and Rayleigh Scattering

The brilliant blue color of the sky is due to scattering by molecules in the atmosphere.

- Visit HyperPhysics: Blue Sky and Rayleigh Scattering for detailed explanations about why the sky is blue and an overview of different kinds of scattering.
- See this University of California article to learn why the sky appears blue, not violet.

Login to Comment on this Item

Why is the Sky Blue?

Perform a scattering experiment on your own to learn why the sky is blue during the day but reddish at sunset.

Advanced Search

Browse Physics To Go by Topic.

image credit: NASA JPL; image source; larger image

Why isn't the Martian sky blue like the Earth's?

The Martian sky is butterscotch, not blue like our own. On Mars, scattering by dust particles predominates, as described in Why isn't the Martian sky blue like the Earth's?.

Atmospheric Optics: Rays and Shadows

See pictures and detailed explanations of atmospheric phenomena at Atmospheric Optics:  Rays and Shadows. Many of the optical effects are caused by scattering sunlight.