UFO Sighting in Las Cruces, New Mexico on May 20th 2011 – Slim object, possibly disc shaped swooped downward very very quickly and dissappeared behind mountain range

Was filming the Organ Mountain range mid-morning in May 2011. Noticed a disc or elongated object streak diagonally from NE to E and disappear behind the Organ Mountain range. Had to slow the video down frame by frame to get the image to show. Must have been traveling very fast due to the frame rate shown in the video. There were no noises or booms to indicate missile testing which happens from time to time. There is a Military testing facility on the other side of the mountain range. White Sands. Usually we can hear the distant booms of ordinance being tested when they do that though. My first thought it was a bug flying by quickly but after looking over and over at the video the object seems to disappear behind the mountains indicating it was a large object? Please see the video attached.