Mommy, Why is the Sky Pink?

Last night on our way to dinner we saw a beautiful pink sunset. Bean loves these types of sunsets because they're her favorite color, pink. She asked me why the sky was pink. And honestly I didn't know the answer. I just said "sometimes the light of the sun reflects different colors in the sky." I love how curious kids are, and it got me thinking about how as adults we often don't even question things that we don't know the answer to any more. We just take them as they are, no questions asked. I believe that being curious keeps you young, and therefore I'm going to make more of an effort to take my daughter's lead and be curious. When I see things that I don't actually know the answer for, I'm going to find the answers. It's so easy to find answers these days, there's no excuse!

So what is the answer to her question? What does make the sky pink at night? I also wanted to know if there was anything to the whole "Red sky at night, sailors delight, red sky at morning, sailors take warning" saying. Here's the complete answer, from the Library of Congess' Everyday Mysteries website.

The colors we see in the sky are due to the rays of sunlight being split into colors of the spectrum as they pass through the atmosphere and ricochet off the water vapor and particles in the atmosphere. The amounts of water vapor and dust particles in the atmosphere are good indicators of weather conditions. They also determine which colors we will see in the sky.

During sunrise and sunset the sun is low in the sky, and it transmits light through the thickest part of the atmosphere. A red sky suggests an atmosphere loaded with dust and moisture particles. We see the red, because red wavelengths (the longest in the color spectrum) are breaking through the atmosphere. The shorter wavelengths, such as blue, are scattered and broken up.

Red sky at night, sailors delight.
When we see a red sky at night, this means that the setting sun is sending its light through a high concentration of dust particles. This usually indicates high pressure and stable air coming in from the west. Basically good weather will follow.

Red sky in morning, sailor’s warning.
A red sunrise reflects the dust particles of a system that has just passed from the west. This indicates that a storm system may be moving to the east. If the morning sky is a deep fiery red, it means a high water content in the atmosphere. So, rain is on its way.