Green fireballs are a type of unidentified flying object (UFO) that has been reported since the early 1950s. Early sightings primarily occurred in the southwestern United States, particularly in New Mexico. Although some ufologists and ufology organizations consider green fireballs to be of artificial extraterrestrial origin, mainstream, non-pseudoscientific explanations have been provided, including natural bolides.
Reports and responses
Early observations of green fireballs date to late 1948 New Mexico, and include reports from two plane crews, one civilian and the other military, on the night of December 5, 1948. These crews described the observed fireballs as a bright "green ball of fire" and "like a huge green meteor". On December 8 another aerial observation of a green fireball was reported by two pilots. In a letter to the U.S. Air Force dated December 20, Lincoln LaPaz, an astronomer from the University of New Mexico, wrote (as reported by the ufologist Kevin Randle) that the observed objects were atypical of meteors. On January 13, 1949, the Director of Army Intelligence from Fourth Army Headquarters in Texas wrote that the green fireballs "[may be] the result of radiological warfare experiments by a foreign power" and that they "are of such great importance, especially as they are occurring in the vicinity of sensitive installations, that a scientific board [should]...study the situation."
A February 1949 conference at Los Alamos attended by members of Project Sign, scientists including Joseph Kaplan and Edward Teller, and military personnel was unable to identify the origin of the observed green fireballs; secret conferences at Los Alamos and elsewhere, later in 1949 and addressing green fireballs, were also claimed by Edward Ruppelt and ufologists including Jerome Clark to have convened. In December 1949 Project Twinkle, a network of green fireball observation and photographic units, was established but never fully implemented. It was discontinued two years later, with the official conclusion that the phenomena were likely natural in origin.
The theoretical astrophysicist and UFO skeptic Donald Menzel claimed to have observed in May 1949 a green fireball near Alamogordo, which he later considered to be an ordinary meteor. Green fireballs have more recently been observed in Japan and Australia.
Some ufologists consider green fireballs to be of artificial, extraterrestrial origin. Along with meteors/bolides, other non-pseudoscientific explanations include sequelae of atomic weapons tests, including clouds of nuclear fallout, lunar material ejected from meteor impacts on the Moon's surface, and aircraft associated with secret military projects.
- ^ a b c d Ruppelt, Edward J. (1956) "Report on Unidentified Flying Objects", DoubleDay
- ^ a b Carpenter, Joel. "Green Fireball Chronology". Project 1947.
- ^ Randle, Kevin D (2014). The Government UFO Files: The Conspiracy of Cover-Up. Visible Ink Press. p. 109. ISBN 9781578594986.
- ^ a b c Clark, Jerome (1956) "The UFO Book: Encyclopedia of the Extraterrestrial", Visible Ink Press
- ^ "DEPARTMENT OF THE AIR FORCE HEADQUARTERS UNITED STATES AIR FORCE WASHINGTON". Project 1947. March 1949.
- ^ E. Gross, Loren (1982). "UFOs: A HISTORY January - June 1949" (PDF). Center for UFO Studies.
- ^ Menzel letter, May 16, 1949, cited at an Air Force Scientific Advisory Board meeting on the green fireballs in Washington, D.C., Nov. 3, 1949. The quoted section read, "Circumstances force me to conclude that the phenomena described are actually real. With regard to Dr. Kaplan's [meteor] explanation, which deserves very serious consideration, I merely raise the question as to why the phenomenon seems to be confined to the Alamogordo region."
- ^ For example, in contrast to his 1949 private statement to the Air Force that he didn't find the meteor explanation totally adequate, Menzel later wrote in his UFO debunking book "The UFO Enigma" (1977) with Ernest Tavres that, "He and several other astronomers present observed the bright green object as it slowly traversed the northern sector of the heavens, moving from east to west: they quickly and unequivocally identified it as a meteor, or bolide..."
- ^ "Mysterious green light 'fireball' spotted in Japan sky". The Telegraph. November 2, 2016.
- ^ "Fireball that lit up Pilbara sky 'something special', but scientists not exactly sure what". ABC News. June 15, 2020.
- ^ "Ominous Green Fireball Lights Up Skies Over Australian Outback". Gizmodo. June 15, 2020.
- ^ Steiger, Brad (1987-05-12). Project Blue Book. Ballantine Books. ISBN 978-0345345257.
- Jerome Clark, The UFO Book: Encyclopedia of the Extraterrestrial, Visible Ink Press, 1998.
- Edward J. Ruppelt, The Report on Unidentified Flying Objects, 1956, Chapt. 4 
- Brad Steiger, Project Blue Book, Ballantine Books, 1976
- Transcript of 1949 Los Alamos conference on green fireballs
- Project Twinkle final report
- Links to other green fireball documents
- Another article on green fireballs and Project Twinkle
- NASA Astronomy Picture of the Day: Photo of a meteor with a greenish tint in tail (20 November 1998)
- Skeptical witness of a green fireball