It was a night at summer and my brother and I had decided to sleep on the roof and watch the sky for shooting stars (house roofs in Iran are flat and have edge walls, safe for sleeping). This was not the first time we are sleeping on the roof in summer, I was rather young at the time and thus slept there with my brother who is 13 years older than me. After spotting a few shooting starts, my brother got tired and closed his eyes to sleep. Within a few minutes I saw an object moving in my peripheral sight of vision. We were sleeping with our feet pointing to south, and the object I saw was moving from very far east toward the middle. I showed the object to my brother instantly, and we both got up and sat while watching the object move steadily. First I thought that it was a white plastic bag flying by the slight wind. But then it was moving too smooth on its path to be something flying by wind. Then I wondered if it was a white bird, but no it was not flapping its wings. It was a oval/orb like shaped object, with no distinct outline or texture or windows, colored off opaque white just like the color of a fluorescent white light bulb that has not been turned on. We both sat and watched the object fly from east toward middle, passing almost above our heads toward west, then stopped for a few seconds and within a very short distance it accelerated and disappeared. Nothing else was witnessed in the sky after that. The object also made no noise during its appearance or movement.