The spotlight that shone down from the craft made it hard for personnel to make out a detailed description of the craft, although estimates range from being three to five feet in diameter largely based on the size of the spotlight. The craft would maneuver dynamically, appearing with the spotlight on, then disappearing, just to reappear moments later over to one side or another with the spotlight on, which was unsettling to those that witnessed it. Supposedly, there was a concerted effort to identify, track, and down the mysterious craft, but it doesn't seem that those efforts were successful based on our understanding of events.
Neither, from what I read. They have no idea:
This is from the NOV 27th article about Guam