Annie Lask saw and heard the UFO, at right, just 20 meters above her, on August 6th, 1997 in a northern suburb of Mexico City. Lask noticed a purple haze in the air and an audible hiss and said, "the outer rim was spinning very fast". The witness doesn't remember getting down from the roof, where she spotted the UFO and had symptoms afterwards. Lask experienced headaches and her eyes burned on a daily basis. You can judge for yourself as to the authenticity of the video in a brief two part You Tube Video of the 1997 sighting. In part two, David Froning, a propulsion engineer with 30 years experience at McDonnell Douglas, judges the UFO to be real and jet powered. Two special effects artists with Digital Domain differ as to whether it is a hoax, but agree the UFO is actually in the picture and not computer generated imagery, or, CGI. Lask's observations leave a critical mind to wonder about the origins of the "purple haze or mist" and the "hiss"? The two part video documentary is less than a half hour about one of the most memorable UFO sightings ever!