Slow moving black triangle. No sounds no lights.We were sitting in hot tub on deck watching the northern and north eastern sky for shooting stars. It was a clear night sky no clouds perfect for seeing shooting stars. The house was east of us so the northern horizion was blocked by the house.While we were watching over the roof of the house into the sky a black triangle with no lights and no sound went over the house. The stars started disappearing as the craft blocked them from our view. The stars reappeared as it passed. When it was directly over head you could make out the variation between the night sky and the black color of the craft. There were very close in color but you could make out the distinct sharp edges of the craft. The bottom was flat as flat can be. The edges of the craft were sharp like a blade not rounded. There was no visable rounding of any part of the craft. The craft was a triangle its sides appeared to be equal. It moved very very slowly I would guess it to be 100 yards across the leading edge and so for the other two edges. I would guess it to have been moving at around 20 to 30 miles an hour.