UFO Sighting in Mountain View, California on May 1st 1968 – hovering disc with flames moving and then it was gone

When I was young about 7years, I am now 54 years old. I was in the kitchen/dining room. I don't remember why my mother and I looked out the window. We did not hear any noise. When we looked out the window during the day, we looked and saw a disc with flames on the outside. I could see that the disc was moving in a circle but it stayed in one place. I could see the the flames moving like a wave. It hovered for a few minutes and then it was gone. My mother and I just looked at each other; I don't remember if there where any words about this, I did not know what I felt. Where I grew up is the same place where Nasa and Moffet Field live.