Whilst looking out of our roof window, I noticed a silver coloured object in the sky. The object was travelling at some speed and was not omitting any jet stream or noise. It was difficult in seeing the exact shape of this craft because of it's distance, however, it was not the shape of a conventinal jet aircraft that would be flying at that height. I have never logged or seen such a sight before and prior to this event I would have described myself a 'non beliver'and of sound mind.