Project 10073 Record: Sighting Report - 9 Dec 66

This document contains a collection of reports and correspondence regarding a UFO sighting on December 9, 1966, in California and Nevada. Multiple observers reported seeing a large, green-to-blue, cone-shaped object in the sky that appeared to split and form an elongated tail with a hook. The reports were investigated by the Foreign Technology Division of the U.S. Air Force. The investigation determined that the sightings were consistent with an artificial cloud release caused by a high-altitude missile launch from the Tonopah Test Range in Nevada. The Atomic Energy Commission and Sandia Corporation had planned a series of meteorological sounding rocket firings using trimethylaluminum (TMA) payloads, which were designed to produce bright blue-green clouds visible for hundreds of miles. The document includes completed FTD Form 164 questionnaires from witnesses, internal memos, and press clippings from the Las Vegas Sun and other local newspapers that confirm the nature of the tests. The Air Force concluded that the sightings were not unidentified phenomena but rather the result of these scheduled scientific tests.