Bright green fireball streaks across Northwestern skyWhile driving northbound on Valley Freeway (167) my wife and I both saw a single bright greenish fireball streaking from SSE to NNW for a duration of aproximately 2 seconds. Since we were looking through our car windshield, our angular vision to altitude was restricted to aproximately 45°. It's path appeared near horizontal with only a slight decrease in altitude. The fireball first appeared almost white and as it streaked lower into the atmosphere, it's color quickly became more greenish in color. It appeared to "burn out" over Seattle. I noticed a very faint smoke trail behind it as it streaked across the sky. It's altitude in appearance when it burned out was equal to that of incoming aircraft to SEATAC. Fortunately no aircraft were in it's vicinity when it burned out. The apparent size of the fireball was approximately 1/8 that of a full moon or more specifically about double that of the brightest star in the Northern Hemisphere, which is Sirius.