During a perfectly clear sunny day, I witnessed a large black circular craft hover high in the sky.

I was walking my dog around 4:30 CST on a bright sunny day and I noticed an object in the sky out of the corner of my eye.  I watched the object wobble high in the sky for approximately one minute until it suddenly vanished as my sight line was obstructed by a tree.  I quickly contemplated what the object could be; a plane, blimp, kite.  I have never seen anything like this in my life.  It was circular, black in color, and was as high or higher then the elevation of a plane.  I was able to gauge the depth of the object by comparing it to birds flying in the sky.  The size of the craft had to be enormous, as it was as big as a full moon would be high in the sky.  I may never know what this craft was, but I can assure you that it was like nothing I have ever seen.
Witness elects to remain totally anonymous; provides no contact information.  PD