Dark silent rough looking craft.I was laying down on chair cushions enjoying the shooting stars. I noticed a rectangular rough looking object flying approx.150mph. No lights and no sound came from it. It was maybe 3-1000 feet from ground level. It was heading eastwards. I was a little frightened realizing it is intentionally meant to not be seen. I hesitated for 20 minutes to call 911. But if someone else seen it then I would feel better about such a strange call. Anyhow 911 responded "what is your emergency"?. I said it isn't an emergency but more a inquiry. Has any one called about a dark large craft flying eastward no sound or lights? They were understanding and asked shape and size. I guessed on size and said about size of a football field but it was more size of a 18 wheeler. I just got excited, I guess.