I had just gotten out of work. i was headed towards my car in a westerly direction and happened to look at the sky. i didn't notice any stars and saw a low flying prop plane, headed in a nw direction towards the airport in troutdale. i then saw a sudden streak of light which appeared to be a comet at first, until i realized it was over cast. it appeared to move in and out of the clouds then suddenly descended while still heading sw. it caught me off guard and left me feeling pretty shaken since i realized there was no way it could have been a comet or asteroid based on it's speed and the direction it was going and it's sudden change of direction.