Triangular - Silent craft

My father , mother , sister and myself were taking some farm equipment back to my great uncles via the back roads between Corry and Wattsburg. It was a very hot quite dark night. We stopped in awe as a craft went over head you could 'feel' it go over but it never made a sound was triangular in shape , no flashing lights just a dim glow at it's edges. It passed over very slowly almost stopping and disappeared over the tree tops. Our truck radio cut out until it was out of sight. Later that evening we saw at least a hundred aircraft , planes and helicopters criss cossing the area and direction that it had taken.
Date is approximate.  PD