round dull metal efo covered in piping on the bottom

When I was about 9, I was home alone my parents just left with my brother and sister. I was sitting on my couch when I heard a loud scraping noise on my roof, although it did not sound scary, sounded like it could just be something logical like a huge tree branch. When I drew the curtains back, just about my house was a giant circle shaped ufo, a dull metallic tin foil color. The bottom was all I could see, it was covered in piping. It was so big, so close, no more than 20 feet above my home, as it passed- another one fallowed. No one seen this but me, I called my friend who live a few blocks up and she had no idea what I was talking about. No one was outside, no one heard it, it was almost like it was only meant for me to see it. Like it camouflaged it’s self to everyone in the world but me. When my parents got home I tried to tell them, I grabbed 2 paper plates placed them together, covered them with tin foil and tried to draw the piping.
Witness indicates that date is approximate.  PD