Spherical Orb GlidingThrough the Sky

This happened when I was about 10 years old and unfortunately I was the only person who saw this.  I was playing with my dog outside in our yard (we lived on 40 acres in the country) and something caught my eye up in the sky.  
At first glance, I thought it was just the moon that you see in the daytime in a blue sky but after a second I realized it was moving.  The object was exactly spherical and shiny silver which resembled aluminum in color and appearance.  It was roughly as high as a propeller plane and emitted not a sound as it very slowly glided across the sky in a straight line.  
I watched it for about 2 minutes.  It was going so slow I thought I could go inside to get my parents but when we came right back out it was gone without a trace.  
It left me with a feeling of amazement because I knew it could be nothing a normal explanation would solve.
Witness indicates that the date is approximate.  PD