One evening I was listening to the local NPR station. The host said that the ISS would be visible that evening at about 10 pm in my area. So, I gathered some friends to watch for it with me. We saw what we assumed was the ISS, but when it was almost overhead, a yellow object instantaneously accelerated away from it at a speed that appeared to be at least double what the speed of the ISS was. The object took off in a direction of about 300 degrees normal to the path of the ISS. I am very sure that the acceleration was instantaneous! The path of the ISS was not altered as far as I could tell. I do not know if the object's path was flat or followed the earth's surface, but it was straight until it disappeared from view.To answer #5, I wondered what the hell it was and thought that surely the astronauts knew about it. I figured I would never get an answer if I inquired about it.