pulsing, mercury in appearrance ,spinning on an axis.Looked as if maybe living or organic in nature.

walking from my high school to my home late afternoon.  Conditions were sunny cloudless sky.  Elementary school field backs up to high school field and at about the middle of the combined ballfields I was compelled to look up.  
his later became peculiar as I realized the entity had made no noise.  I was either preoccupied with entity and/or completly unaware of any outside stimuli ie/noise moving objects, etc.  
About three telephone poles height above ground appeared a single spherical, spinning "mercury" like in appearrance entity or object.
I procceeded to observe this object while lying on my back on the grass of the field.  It seemed to spin at a regular pace but sort of pulsed as a heart might.  The entity certainly was at least aware of my presence as it moved jn an unnatural process from a distance within my perceivable range of sight [without moving my head] to the right and then left of the center with ease.
Then it came closer and then farther and was kind of putting on a show of its capabilities.  Suddenly it was gone as if it disappeared into thin air.
Witness indicates that the date of the sighting is approximate.  PD