I was sat in the living room of my 2nd floor flat watching tv at 0350 BST on the 24th July 2012 when I noticed a REALLY bright white light shoot over the rooftops of the houses opposite and to the right of my window as you look out of it. My window faces East towards Portsmouth and the small row of 3 terraced house rooftops this thing flew over are at a 90 degree angle to my flat as i look out my window, so the rooftops run west to east. (Hope that makes sense)Now my living room window is pretty big, about 2.5m wide and 1m tall and my TV is in the corner to the right hand side, so when i'm sat on my sofa the window is just naturally part of my peripheral vision. It was so quick and as soon as I'd seen it, it was gone.It was silent and was going from west to east. It wasn't the ISS because i checked and I watched that fly over head at 0418 BST as predicted and that was very dim.What I saw was as bright as those "day sun" lights on police helicopters Very bizarre, I almost wouldn't of believed my eyes but it was SO bright and moved SO fast.