A 15 year old sees a small hovering cylinder in the Azores, Portugal.I was aware of a faint pulsing sound which was keeping me from getting to sleep. This pulsing had been going on for about 7 minutes, so I decided to have a look out of my bedroom window to see what was causing this sound. I looked out, and as we live in a small village with no street lights it was hard to see. The bungalow opposite us has a 40 feet high water tower behind its garden, and I noticed a small 'trash can' sized cylinder slowly moving up and down over it. It was hard to see what color it was, but it was light, maybe white or a pale gray. It had a domed roof. I was able to look at it for a minute or so before it quickly headed west and gained height. The pulsing stopped when it left. My parents laughed when I told them and said it was probably a helicopter (my dad used to fly Sea Kings for the RCAF), but I know it was too small and quiet to be a heli. Another thing I noticed was that it left a smell of burnt rubber. 100% sure it wasn't a helicopter.((NUFORC Note: Witness elects to remain totally anonymous; provides no contact information. PD))