The "Many Colors And Moods Of The Sun" Story

It was an ordinary day.  Hot and humid!  In my part of the world it is the end of summer with temperatures in the high 80s and low 90s in Lancaster, Pennsylvania.  We do have storms from time to time which help to keep the grass green and the water in our backyard pond at the top.  Some days white puffy clouds fill the sky while other days the sky is a beautiful blue with not a cloud in the sky.  The bright yellow sun tends to warm our blacktop driveway and make walking on it with bare feet impossible.  As I look up at the sun in the sky I often wonder why it's yellow in color instead of green or even cobalt blue.  

The sun appears white in this photograph

But, you know that if you observe the sun at sunrise or sunset, you'll witness it undergo a variety of color changes from orange to sometimes purple.  That's because the sun has no color and emits a clear, white light that can be changed by the atmosphere of Earth.  The sun emits light at different wavelengths that are scattered by the atmosphere and the wavelengths that remain happen to combine to make the yellow we believe is the color of the sun.  

Here the sun appears yellow.

And, when your location on Earth is closest to the sun, usually in the summer, the hotter it feels.  But, is that really true?  Do you realize that when the Northern Hemisphere experiences summer, it is actually at its farthest point away from the sun.  Shouldn't it be the opposite?  It's that way because Earth's orbit is slightly elliptical and during the summer months the Earth is tilted slightly towards the sun which increases the amount of time it sees sunlight, thus makes for a warmer temperature.   Some people believe that the sun does not rotate, but sits still at the center of the solar system.  

The sun appears red in this photo.

But, the sun does in fact rotate around an invisible axis.  This fact was one of Galileo's most important discoveries.  It was also discovered that the myth that sunspots are colder isn't true.  The average surface of the Sun is 5,500 degrees Celsius and even the cold spots we say we see could still melt most solid objects.  The sun is always emitting energy into space and it is this energy that makes life possible.  At times it emits a more powerful burst of energy in the form of solar wind and coronal mass ejections.  These events can cause havoc on electronic items, but the actual pressure never reaches Earth.  Our sun is an amazing object be it white or yellow or any other color you might imagine it to be.  The next time you look at the sun, be it sunrise or sunset or when it is behind the white puffy clouds in the sky, remember all the things that it really is as well as what it isn't.  Facts are always better than fiction in science.  It was another extraordinary day in the life of an ordinary guy.