This happened back in 92 and I decided to post it because someone else may have encountered it and my story may help. I was not able to get a photo.My girlfriend and I were on our way to California. We were driving on highway 50 headed west some miles after we drove through Eureka. It was around midnight or 1 am. My girlfriend was asleep in the front seat. As you drive on highway 50 through the desert in Nevada you go through valleys from one set of hills to the next and on average the valleys are around 15 to 25 miles across. I looked in the rear view mirror and saw a bright ball of light coming fast and steady straight up the highway behind us. It passed over our car headed west lighting up the highway as it went. As bright as it seemed it only lit up the highway about as wide as the highway was. It glowed pure white and had no streak or meteorite like tail. I could only see light and no structure other than it was a perfect sphere about 30 to 50 feet in diameter. There was no sound and no air disturbance. (it didn't stir up any dust or debris as it went) I estimate as it passed over head and down the highway in front of us that it was little more than 100 ft. off the ground. It disappeared silently over the next set of hills in a matter of seconds. If I had to estimate a speed I would guess in excess of between 800 or 900 mph. Maybe more. I was in the Navy and regularly observed fighters during war games making passes at speeds of 500 to 600 mph and they seem slow compared to the way this object moved. The whole event lasted around 30 to 45 seconds.