Dark metallic disc no lights or noises it moved slowly, smoothly and then sped away very quickly.

My father was standing outside on a clear pre-dusk day in the late summer. It was before dusk so there was plenty of light. He yelled out "Oh my God come take a look at this." My mom and I were in the house and it sounded like an emergency so we ran as fast as we could too my dad. He was standing outside looking at the western hills. We looked in the direction he was looking and pointing and that's when we noticed a dark metallic disc shaped thing moving slowly towards us in a diagonal direction. The disc made no noise and there were no lights. It was flying lower than a commercial or millitary plane. It was at an altitude that most of the local pilots fly. We could see the disc clearly,there was nothing to hinder our view and there was plenty of light because it was before dusk. The object moved smoothly and slowly towards us. It eventually moved over us where it hovered above us for a few seconds. I had a clear view of its underside where I noticed once again that there were no lights, it was noiseless there were no evident engine noises. I also noticed that there were no windows or doors- if there were any I couldn't see them. After a few seconds the object then began to move in the same diagonal direction towards the eastern hills where after a few seconds of travel it suddenly sped away very quickly over the hills.
Date is approximate.  PD