As I was driving south to work on 880 in Hayward this morning, there was an amazingly bright bluish fireball visible in strong twilight at ~6:40 AM that traveled slowly on a trajectory from about 40 degrees elevation towards the southwest. I could easily follow it to nearly the horizon. It was mesmerizing, so I'm glad I didn't drive into the next lane. I've never seen anything like this before - anyone heard reports of a rocket or space debris burning up this morning?