In late 1979, an American “Vela” spy satellite picked up a mysterious bright flash near Antarctica. Since then, experts have debated what “The Vela Incident” really was–a meteorite? An illegal nuclear weapons test? A malfunctioning satellite sensor? An exploded UFO? Today the mystery still remains unsolved.
Vela 5 Satellite, on display at the California Science Center, Los Angeles
In 1963, in the world’s first nuclear-weapons arms-control treaty, the US and the Soviet Union agreed to halt all atmospheric testing of nuclear weapons. To monitor the Soviets and look for signs of illegal testing, the United States launched a series of surveillance satellites called “Vela”. The Vela satellites could watch the entire planet, and used a combination of gamma-ray, neutron, EMP, and x-ray detectors, and a pair of light-sensors called a “bhangmeter” to search for above-ground nuclear explosions. From 1965 to 1969, the US launched 12 Vela satellites. They orbited quietly, monitoring the 41 known nuclear tests that were conducted in that period (from France and China, who had not signed the treaty), and detected nothing unusual or unexpected–until September 22, 1979.
At about three in the morning local time, one of the Vela satellites, number 6911, orbiting between the Prince Edward Islands, a small bit of land near Antarctica that was owned by South Africa, and Bouvet Island, an isolated speck owned by France, picked up an intense flash of light in the area. At about the same time, the Arecibo radio telescope in Puerto Rico picked up a large electromagnetic disturbance in the ionosphere. Clearly something unusual had happened.
When analysts looked at the data from the Vela, they were shocked to see the characteristic double-flash of a nuclear explosion. The double-flash is produced when the expanding shock wave passes the expanding fireball and then dissipates–no known natural phenomenon produces such a distinct signature. The particular satellite 6911 had already previously detected a total of 12 double-flash events–all of which turned out to be a French or Chinese nuclear weapons test. To try to confirm that the satellite had indeed detected a nuclear explosion, the US sent two dozen different planes to overfly the suspected area looking for traces of radioactive fallout. They were mystified when none was found. Weather patterns would have taken the fallout towards Australia, and researchers near Queensland did find low levels of iodine-131, a nuclear fission product, but researchers in New Zealand did not detect any.
Analysts then took a look at the satellite itself. Vela 6911 was one of the later-series “Advanced Velas” that was launched in May 1969. Originally planned for a lifespan of 18 months, they were later cleared for operational lifespans of at least 7 years, and some of them remained operational until the early 80’s. Satellite 6911 was already known to have technical issues, however–its EMP (electromagnetic pulse) sensor was no longer working. Most of the other Vela satellites were not in a position to observe the flash, but one may have been–and it detected nothing. On Vela 6911 itself, both of the bhangmeters detected the flash, but the wavelength ratios were different in each. This raised the possibility that the flash was a spurious event, caused either by some kind of hardware malfunction, or by the impact of a tiny micrometeorite with the satellite equipment.
In 1980, President Carter appointed a panel from the Office of Science and Technology to assess all the available data and determine what had happened. The panel concluded that the Vela Incident “was probably not from a nuclear explosion”. One hypothesis offered by the panel was that a micrometeorite had hit the satellite, causing a small piece of the outer skin to break off and briefly reflect sunlight into the sensor array.
But the “faulty satellite” hypothesis did not explain the atmospheric disturbance found by the Arecibo radio telescope. And in the 1990’s further evidence appeared, when it was revealed that the super-secret undersea network of microphones called SOSUS, used to track Soviet submarines and whose existence was completely unknown to the 1980 panel, had recorded the muffled thud of a distant explosion on the early morning of September 22, 1979, once again raising the possibility that it was a nuclear explosion. But others have concluded that there’s no solid link between the reported atmospheric disturbances, the sound of an explosion, and the flash–they may all be unrelated events.
Today, the most popular theory among most researchers is that the Vela Event was a joint Israeli-South African nuclear test, of a device producing between 2 and 4 kilotons. It was known in 1979 that Israel had been secretly building nuclear weapons, and it was also known that the apartheid regime which was then ruling South Africa had also begun its own nuclear weapons program. Today, we know from documents released after the fall of the apartheid regime that South Africa did not have enough nuclear material for its first bomb until November 1979, two months after the Vela Incident. But Israel was already producing fissionable material and bombs. Israel and South Africa were both at the time international pariahs who were subjected to arms embargoes, and they had already conducted joint military research in several areas, including new jet fighters. Since 1980, a number of writers and researchers have talked with anonymous Israeli and South African officials who have declared that the Vela flash was from a joint Israeli-South African nuclear test. But nobody has stepped up with any documentary proof of it. While Israel would still have the motivation to hide a joint nuclear test, South Africa no longer does. On the other hand, it is known that the apartheid regime had destroyed most of the materials and reports relating to its nuclear weapons program, because it did not want a Black-controlled government to have access to such weapons or the ability to build them.
Was the Vela Incident a nuclear explosion, and if so, was Israel or South Africa involved? It remains a mystery today.
Hidden History 
I was still a boy at the time, but I remember the incident made some waves in the local press. The government assured us that no nuclear tests were conducted. 😉
It does seem clear that it was a nuclear explosion (the double-flash is distinctive and is not known to be caused by anything else), The question is WHOSE nuke was it….? My feeling is that if it were indeed South African, somebody would have blabbed it by now–the current government has no reason to hide that sort of information about the apartheid regime. Israel, on the other hand, still has every reason to hide it, if it was their nuke….