Why is the sky blue? The age-old question explained in video.

It's an age-old question and one that any meteorologist hears quite often. Why is the sky blue? It has to do with light waves and how they travel through our atmosphere.

The light from our sun travels 93 million miles to reach the surface of the Earth. That's like taking 195 round trips to the moon and back, or more than 3,700 trips around the world.

This light looks white to our eyes, but in actuality it is comprised of all the colors of the rainbow – red, orange, yellow, green, blue, indigo and violet.

Why does the sky look blue?

When this light hits the Earth's atmosphere, it collides with various particles and gases which act to scatter the light in all directions. This process is called Raleigh scattering.

All light energy travels in waves. On one end of the spectrum, you have the long "lazy" red waves. On the other end are the short, choppy blue waves.

Because of their shorter nature, blue waves are scattered much more than the other colors, and therefore that is what we tend to see when looking to the sky from the Earth's surface.

What about orange sunsets?

But the sky doesn't always look blue. Occasionally we get a beautiful red or orange sunrise or sunset. This occurs because the sun's rays have to travel a longer distance, through more atmosphere during these times of the day. This causes more scattering of the blue light, allowing the longer red and orange wavelengths to make it through to our eyes.