Verifiable sighting

Well, I was just about to fall asleep that night, when a light when a light went by my window.  I was curious, so I got up and went to my big, picture windows.  I saw a craft right flying very slowly just above my front yard.  I was speechless.  
I followed it around the perimeter of my yard and then it hovered there for a second or two.  The craft was huge, with revolving, white lights on the bottom.  It was close enoough that I could see it was silver or gray in color.  It was also completely silent.  
After it hovered for a second, it took off in the distance at an incredible speed.  It zigzag left, then right and then was gone.  
My grandmother happened to live one house over from me and she called my mother in the morning telling her that she saw exactly what I saw.  
Then on the radio that day they were joking about numerouos people calling into the station reporting that they saw a UFO.  It was no joke.
Source is anonymous.  No date is indicated by the witness.  PD