Question: Why is the sky blue?

Jared Parnell answered on 10 Mar 2015:

The sky is blue because of the way our atmosphere (the air around the earth) affects light as it travels from the sun.

Light is made of tiny little bits called photons and you can think of each of these as having a colour (or wavelength in science lingo!). The tiny particles (molecules) of air affect each of these photons differently. All the photons get scattered in different directions but during the day it is mostly the blue ones that get through.

In the evening it is just the orange, yellow, and red ones (with less blue) which is why we get nice sunsets.

At night there is very little sunlight so we can see all the way to the stars (although there is usually a little light that still bounces from the moon but not enough to cause the blue sky).