clearly a flying suacer, solid, bright, silent , hovering at the top corner of a high rise building then flying away in an instant.Approximately Dec. 21, 1980 my sons Jason (age 7) and Michael age 10) and I (36 yrs old at that time) looked up to the sky and saw a large, bright, flying saucer flying over the top of a large high rise building in Mexico City, Mexico. We were heading home to our hotel while on a Christmas vacation. My husband was well ahead of us and although we screamed to the top of our lungs and jumped up and down to get his attention, did not believe us and never turned around to see it. The “saucer” was very bright white, had many windows all the way around it, was very silent and came from behind the building, hovered over us and the building and then proceeded to go very quickly back up and disappear. We were more excited than frightened, but it was also rather alarming because we had never seen a flying object move like that in terms of silence and speed. It was very bright and made of a solid material. The windows did have light in them, but we did not see any objects or living creatures inside the windows.((NUFORC Note: Witness indicates that date of incident is approximate. PD))