The circular shaped object came from behind a cloud at great speed and disappeared behind another,not coming out the other side.It was a very sunny day with white fluffy clouds, I had on my sunglasses and had been sitting in my back garden, when I looked straight up and from behind a cloud this circular shaped object with a dark top and silver underside, came accross the sky at great speed and went behind another cloud. So I looked to the other side of the cloud thinking as it was going appear there, but it didnt !!! I scanned the sky for ages but never saw it again. It was only in the blink of an eye I saw this object, but I do believe it was NOT man made, because of its speed.((NUFORC Note: Witness indicates that date of incident is approximate. PD))