4/09/2010 at approximately 9pm outside in a southwestern arizona city, 2 people observed an unknown occurrence. It was a warm, cloudless, still night and my son and I were sitting in our backyard, as my son was reclined on a bench looking up at the night sky. All of a sudden my son exclaimed that he saw what looked like a soft white single color ribbon, flying silently across the sky, it was perhaps 45 degrees off the eastern horizon, flying south to north and within a few seconds quickly faded as it moved across the sky. The distinct shape never changed, and there were no distinguishable individual lights that he could see. Shortly after that we caught sight of another formation exactly like the first sighting flying south to north directly overhead, silently, and at approximately 80 degrees off the horizon. It was a somewhat translucent, solid light, with the curved leading edge the primary visible structure. It was a distinctly curved object, (perhaps boomerang shaped)- that was only visible for a few brief seconds before fading away.We caught a third shape of the same formation shortly after the second. It was in the same location the first sighting was and faded quickly. The object seemed very large, quiet with a faint white, luminescent light emanating from it. Each sighting the object looked like it was at a different elevation in the nighttime sky, perfectly formed. And although we saw 3 distinct things fly through the sky that night above us, they were separate and exactly the same shape, although different sizes. It had a definate edge all around the curved shape. It was as if we were seeing something that was almost completely invisible, except for the curved leading edge of the crescent. I don't know how large the objects were, but they must have been very large and high in altitude, because we lost sight of them in a matter of seconds. We are located in the middle of a medium-sized city, lots of lights all around us. Two military bases are located in the vicinity. (MCAS and Army Testing Ground).