My Co worker & I got off work @125 & we headed south on hwy 99. We were on the road for about 3 min when I thought I witnessed lightening strike in the middle of the sky. Something rang strange in my head because lightening doesn't strike usually that high up in the sky & it seemed to be a very short lightening strike. I looked directly at where it occurred & I saw a set of pulsating light. They were going from side to side in a orchestrated manor. I notified my co-worker & she witnessed it as well. We noticed it was descending lower & heading north. It moved close enough for USA to see it was teardrop shaped. It was as if the teardrop was on it's side & it had four panels of groups of lights. They flashed in sections from the rear to the front. As they were pulsating, we could see that the UFO had structural integrity & it appeared to be mechanical flying with no engines, propellers, or anything of that nature. There were no windows on it & the front of the UFO showed a build up of heat or some kind of distortion of matter present when a jet is traveling at a supersonic speed. Its flight pattern was very unnatural. As it passed us it was very disturbing & a little frightening to experience. There was a car in front of us. They pulled over but we continued driving to our destination.