About 9:00 pm I took the dog out into the back yard to use the bathroom, as I was waiting I looked up to look at the stars. That's when I noticed about 15 lights in the shape of a large airplane or a piece sign, witch I thought was odd because airplanes don't have lights that outline it's shape. I kept looking at it as it flew overhead then in a blink of an eye the lights changed shape into a chevron, after a few seconds the lights changed shape again into a circle except for one light that got out of line a little then quickly got back into place.It never changed shape again for the rest of the short time I was able to observe it. I then went into the house and told my wife we went back outside for awhile but she never saw it and I've never seen it again. I will note the whole time it was changing shape it never deviated from its flight path witch was sw to nw right passed Offut Air Force base, the objects were only about a thousand feet above me and never made a sound.