Was driving on US 101S and observed event at 2100 local approximately five miles prior to the Mariposa Reina exit. Event lasted less than a second. Neon green object took straight, non-parabolic trajectory from top of my field of view as seen through windshield towards a point approximately 15-20 degrees off vertical to the right and towards the horizon. Object disappeared potentially impacting mountain or going behind mountain with no audible sound nor visible explosion. Brightness was similar to a flare or an exploded firecracker. No other activity noted after event. Location is between Vandenberg AFB and Pt Magu Naval Station.
