like standing under the hull of an aircraft carrier that is broadside to you

completely black (like Maglite flashlight), reflected ground light (glistened slightly like wet but not wet), totally silent, 400-500 feet off ground, moved extremely slow(40mph)NB, minimum width 1200 feet max 2000, length perhaps same (my view looking up as it had already passed overhead was from the (rear of craft?), like seeing aircraft carrier hull passing overhead sideview, perhaps triangular(only saw the bottom rear, height 200-300 feet(bottom to top), it didn't seem concerned that it could be seen (personally I felt as insignificantly as an insect)