20:05 hrs., Dallas, TX, wedge shaped object passing approximately 150 feet above house, moving NW to SE at approx 15 mph.At exactly 20:05 hours on the evening of December 5th, 2008, I was in my back yard walking my dogs along with family cats. Only lights on was backdoor light. Dogs were running around yard as usual. What drew my attention to object I witnessed, was one of my cats, who would normally stay distance from me, ran towards me and stopped right by my right leg. She sat down and was looking up over the roof of house. I looked at the cat, thinking she was probably just looking at plane lights or maybe a bird so something. She kept looking, so then I looked up to see what she was seeing.What I believed I saw at first, was a mass of bird flying over, and more than likely geese, since the formation was sort of looked liked a shape of geese migrating. But then reality hit me. It was moving at approximately 10 to 20 mph, almost parallel to my street, but when I focused on it, I then could see, that it had mass, and structure of a wedge shape. It was close enough that I could get a base size from comparing it to the roof of my home. The overall length was approximately 100 to 150 feet long, and height was approximately 7 to 10 feet, and it was only 100 to 200 feet from the ground. I was looking at the right lower quarter, from bow to stern. There weren’t any lights or any sound what-so-ever emitting from the craft. The right side was visible because of the lights of homes and a few street lights carried to that height. I also had a small private aircraft flying at one to two thousand feet at about 2 miles southwest of our location, so I could get some variable and we have high pecan trees which also gave me some comparison to height from the ground.What was apparent, the side wasn’t a smooth surface. I say this because you could see dark and then somewhat lighter shades. This to me could have been either two assumptions: 1. The surface was painted, as we do some of our military aircraft, so it will blend in with the sky (clouds lighter and darker) or 2. the surface had angles on it which would show lighter for the parts protruding out and dark for the area that was indented. This is similar to our stealth aircraft for displacing radar. The light of homes and street lights were barely hitting the surface of the object but it was enough to make out the details.I yelled at my wife, who was inside. When she came out, the object had only moved ¼ of our block down the street. I tried to have her follow my arm movement to look down the length of it to be able to see it. By the time she was in sync with my movement the craft had gained some altitude and was moving away. The rear of the craft seemed sort of blunt, not the shape appendage you would expect from a tails of an airplane. It then moved away out of sight, not at an accelerated rate but at a constant speed.My background is journalism. I’ve spent over 6 years on U.S. Navy aircraft carriers and 6 years on Navy Air Stations, documenting Navy fighters and bombers in flight. I also was piloting Cessna 150 and 172 aircraft years ago when I started pilot training, so I’m used to aircraft design, determining what you visually see before me in order to navigate and anything associated with flight. And being a photo journalist I’m very good when it comes to attention to detail. I wasn’t mentally rattled and didn’t lose my composure but the event left me with allot of questions. A male friend of my wife at her work, who lives in north Dallas County saw something similar, same design, but with more than one object just a few months ago.