Pedagogy in Action > Library > Conceptual Models > Conceptual Model Examples > Blue Skies & Sunsets

Blue Skies & Sunsets

Starting Point page organized by R.M. MacKay.
This material was originally created for Starting Point:Introductory Geology
and is replicated here as part of the SERC Pedagogic Service.


This conceptual model explains why skies are blue and sunsets are red. Related hyperlinks are provided with text and images to make this easy to present and discuss in an introductory Earth science course with atmospheric content.

Learning Goals

Students will learn about

Context for Use

Appropriate for use in Climate Change, Earth System, or Meteorology courses to introduce the electromagnetic spectrum and the scattering of electromagnetic waves by the atmosphere in a context familiar to the everyday experience of students.

Description and Teaching Materials

Included are:

Teaching Notes and Tips

After discussing this model for the scattering of visible light by the atmosphere, other parts of the electromagnetic spectrum can be introduced (UV and IR). This conceptual model can also help begin a more general discussion of light scattering by aerosols and cloud dropplets.


Follow-up questions on exams, homework, or in class discussion can be used to assess student understanding.

References and Resources

The link above, Good hyperlink reference on sky color (more info) , also contains information on Mie scattering, Rayleigh scattering, and other related topics.

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