Skeptics
Skeptics have suggested that the UFOs were actually oil platform burn-off flares of the Cantarell oil field located around, some 240 kilometres (149 mi) to the north west of the aircraft. This would have placed the objects near the horizon so as to appear on the same level as the aircraft. Captain Alejandro Franz analyzed the latter option and published his results from July 2004 to May 2008.
Mexican Air Force FLIR's video lights are not UFOs. They are now confirmed to be oil well gas flames. The AN/APS 143 Radar video is unavailable and the targets detected could be vehicles on the Yucatán's peninsula highways
Read more about this topic: 2004 Mexican UFO Incident