Spherical UFO witnessed in the 1960's which was ON THE GROUND.

In the mid 1960's, I witnessed a spherical-shaped UFO on the opposite side of the play ground of the school located across the street from my house.  The object emitted a pulsating sound and the luminance was pulsating as well.  I would estimate that the object was approximately 15 to 20 feet in diameter.
My original impression was that this was a meteorite.  However, I later believed this to be incorrect, as a meteor of such size would have razed the entire neighborhood.  The object had to have made a soft landing, indicating that it was under intelligent control.
The UFO was on the ground for about 2 hours, which prompted one of the other witnesses, a girl who was rather brave,  to walk in close proximity to the UFO.  I remembered being afraid for the girl's safety since she was getting dangerously close to the object.  I would estimate that she was within a few feet from the object, when I left the scene and headed back to the house.
Upon entering the house, I informed my dad about what was happening out on the playground.  However, he found the whole story difficult to believe.  I also remembered showing the site to a fellow classmate the following day and noticed the impression in the ground at the location where I saw the UFO.
I informed Peter Davenport that I would attempt to locate the girl and that search is ongoing.  I have also supplied a satellite photo of the area with markings that approximate the locations of each item.
Witness indicates that the date is approximate.  PD