The sky is blue during a clear, sunny day.

This has to do with how light is scattered off of atoms and molecules in our atmosphere.

Sunlight is made up of different wavelengths (colors) of light.

You can test this by holding a prism up and passing sunlight through it.

You will see the different wavelengths from violet to red.

This is also how we get a rainbow after a rainfall where water droplets in the atmosphere can act as a prism.

Atoms and molecules in the atmosphere scatter light of different wavelengths differently.

The blue wavelength is scattered more than red.

So a clear, sunny day has a blue sky.

During the sunset, however, we see different colors like orange, pink, and red.

Atoms and molecules in the atmosphere are still scattering light but now we have moved further away from the Sun as the Earth rotates.

Some of the blue light gets scattered away and the red and orange light reaches our eyes. This is what makes the sky red.

Enjoy the sunset (and the sunrise if you are a morning person)!

BY THE WAY…

If you are looking for STEM resources for kids interested in science, below is an article I wrote a while ago with a number of suggestions. I will be sharing more resources to help with homeschooling kids on this website.

STEM resources and ideas for kids interested in science