In the area of February 1-2, 2018, in the state of Washington, the following video was filmed near the tourist base on the Cascade Pass:
In the video, as it might seem at first glance, an airplane is flying, leaving a contrail behind it. However, when you zoom in on the frame, you can see that an object is flying, approximately of the following shape:
If we evaluate the video very strictly, then we should first of all assume that this is a kind of light-atmospheric effect, which is sometimes observed when aircraft are flying:
The example of such images shows that in the case of a contrail, its shadow is long, almost infinite. The magnification allows you to see the glimpse from the aircraft. This is not observed in the video, which allows us to consider: a huge cigar-shaped object, at least a kilometer long, flew over the state of Washington. As far as Wikipedia can be believed, there are no such devices in service with the Pentagon.