Thirty-four years ago today, on September 22, 1979, an orbiting satellite called Vela detected two strange flashes in the sky near the Prince Edward Islands in the South Indian Ocean, not far from Antarctica. The “double flash” pattern observed by the satellite was consistent with a low-yield nuclear explosion, two to three kilotons. If it was a nuclear explosion, something was obviously very, very wrong: nuclear testing in the open atmosphere has been banned since the 1963 Nuclear Test Ban Treaty, and obviously no country would claim responsibility for violating it.
Was the double flash a nuclear test? It’s not entirely certain. Although the data received from Vela was consistent with that, the satellite itself was not working at 100%. Its EMP (Electromagnetic Pulse) sensor was malfunctioning, and it was already two years beyond its designed lifetime. Vela had itself been bamboozled a few years before when a “superbolt”–an unusually strong charge of lighting–struck over Newfoundland, which Vela also registered as a nuclear explosion. It could have been detecting another such superbolt, which for unknown reasons were common in the late 1970s, or it could have been a meteor strike or other atmospheric phenomena.
It bears mentioning that the purpose of Vela was to detect nuclear explosions in violation of the Test Ban Treaty, thus validating the principle that if you’re a hammer, everything looks like a nail.
This is a Vela satellite, which is why, at least in the 1970s, you couldn’t get away with popping off a nuke without everybody knowing about it.
Obviously concerned, the world superpowers investigated the incident. The U.S. Air Force flew numerous recon missions into the area but found no trace of radiation consistent with a nuke blast. Other instruments which had previously detected atmospheric explosions showed nothing this time. President Jimmy Carter, then negotiating an important arms control agreement with the USSR, commissioned a special study on the Vela incident. In the summer of 1980 the panel reported that it probably wasn’t a nuclear explosion. But others, especially in the intelligence services, were unconvinced.
If it was a nuke, who set it off, and why? We don’t know, but the leading theory is that it was a joint secret nuclear test between Israel and South Africa, both of whom were known to be developing nuclear weapons, and both of whom denied having them. South Africa voluntarily gave up its nuclear weapons in 1989 and the UN certified it was nuke-free in 1994; Israel has continued to deny having the bomb, though almost everyone is convinced they do possess nukes. In the years since 1979 various “admissions” and opinions have been published in numerous places suggesting that it was a nuclear test, but none have been conclusively validated.
The truth is we have no idea whether the double flash in the sky on September 22, 1979 was a natural event or a nuclear explosion. Whatever happened that day remains a historical–and scientific–mystery.