Luminous green flashing object above Fajada ButteNot sure of the exact date but it was within a week of 5/15/11. Witnessed a green flashing (shape changing) object not more than 50 feet above Fajada Butte for 5 seconds or so. The object vanished without a trace. I was about 1 mile north of Fajada Butte and was looking directly at it when it appeared and disappeared. I have never seen anything like that in my life. Coincidentally, I heard from a very reliable witness (park management employee)of a similar green luminous object witnessed a few months earlier by at least 10 people attending the park observatory night sky program. The green object reportedly hovered 100-200 ft above the valley floor and then moved slowly across the valley and was seen passing behind Fajada Butte before dissappearing completely. I apologize for not posting this soon after witnessing the UFO so I could give an exact date. This is one of 2 UFO sightings I witnessed at Chaco Canyon within 4 days of one another.((NUFORC Note: Witness elects to remain totally anonymous; provides no contact information. PD))