Green fireballs were mysterious luminous objects observed over the American Southwest between 1948 and 1951. Distinguished by their unusual green colour and strange flight behaviour, they captivated scientists and the public alike.
Primary activity was observed over New Mexico, particularly near military installations and the Los Alamos laboratories.
Unlike ordinary meteors, they left no trails, moved horizontally, and maintained their brightness for extended periods.
The US Air Force launched a special project called "Twinkle" to study this unexplained phenomenon.
First documented observation by two aircraft crews over New Mexico. Civilian and military pilots report unusual green luminous objects moving slower than typical meteors.
Second sighting by military aircraft crew. Reports describe "large green glowing spheres" with uniform speed and brightness, unlike conventional fireballs.
Conference at Los Alamos featuring Edward Teller and Joseph Kaplan. Dr Lincoln LaPaz from the University of New Mexico begins official investigation, collecting witness testimonies.
Peak activity period: over 100 sightings recorded in a single month. US Air Force expresses serious concern about the phenomenon's frequency and proximity to military installations.
Launch of "Project Twinkle" - a classified US Air Force programme to study green fireballs. Installation of specialised camera networks across New Mexico.
Project Twinkle officially terminated without explaining the phenomenon's cause. Conclusion: "probably of natural origin." Sightings dramatically decrease following project closure.
This was not an ordinary meteor. The object moved horizontally, maintained its bright green colour for several seconds, and left no trail whatsoever. In 30 years of observing the night sky, I had never seen anything quite like it.
At first I thought it was a signal flare, but the colour was far too unusual — bright green, almost neon-like. The object flew past our aircraft at approximately 2,000 feet altitude.
I observed this phenomenon for eight seconds. The sphere moved from north to south, maintaining constant speed and brightness throughout. No sound was audible whatsoever.
The green light was so brilliant it illuminated the entire area around our ranch. Our cattle became frightened and remained agitated for several hours after the incident.
Over 200 official reports from military pilots and civilian eyewitnesses
Several blurred photographs taken by chance witnesses
Short fragments of 16mm film captured by military cameras
The phenomenon genuinely exists and is not mass hallucination or hoax
Several photographs and spectral data obtained, confirming green luminescence
The nature of the phenomenon was never established. Project closed without definitive conclusions
Official report on the results of the 20-month investigation
Download PDFGreen fireballs could have been a special type of meteoroid with high concentrations of copper or other elements that produce green luminescence when burning up in the atmosphere.
The phenomena might have been clouds of radioactive particles from nuclear testing, illuminated by sunlight and creating unusual atmospheric effects during the height of the Cold War.
Possibly experimental aircraft or weapons being tested at classified facilities in New Mexico, featuring advanced propulsion systems that produced green exhaust trails.
The most popular ufological theory links green fireballs to alien reconnaissance craft studying American nuclear facilities during the early Cold War period.
According to this theory, the phenomenon was artificially created to distract attention from genuine secret military developments or to test public reaction.
A more exotic theory suggests the objects originated from parallel dimensions through spacetime portals opened by nuclear testing.
Green colour in cosmic objects is typically associated with the presence of copper, magnesium, or oxygen. When burning up in the atmosphere, these elements produce characteristic green luminescence. However, the intensity and duration of Green Fireballs' glow was unusually high for ordinary meteors.
Mass sightings declined sharply after 1951, coinciding with the closure of Project Twinkle. Possible reasons include: changes in meteor shower trajectories, completion of secret tests, or simply reduced public interest in the subject.
Yes, similar green light phenomena were recorded in Australia (1960s), Canada (1970s), and Scandinavia (1980s). However, none reached the intensity and regularity of the American Green Fireballs.
Most contemporary astronomers lean towards the meteor hypothesis, suggesting it was an unusual meteor shower with a unique chemical composition. However, some aspects of the phenomenon still lack satisfactory explanation.
Whilst Green Fireballs are often mentioned in ufological literature, the scientific community finds insufficient evidence for extraterrestrial origin. Nevertheless, the complete mystery of the phenomenon leaves room for various interpretations.
Rare green meteors are observed even today, particularly during major meteor showers. Modern sky monitoring systems detect such phenomena, but they are significantly rarer and less intense than the original Green Fireballs.