Saw a large bright light heading up and to the south.

I was standing on my back porch smoking a cigarette in Castle Gardens subdivision, west of Newburgh rd and south of 5 mile rd. I was facing East and saw a large bright white light moving up and to the south. It was not an airplane and not a helicopter. I followed it as it rose up and then the light got dimmer and dimmer until it vanished. I have never seen anything like it before and there were no clouds in the sky for it to fly behind. I've been stumped every since I saw it and have no clue what it could have been.