Vela Incident From Wikipedia, the free encyclopedia Jump to: navigation, search Orthographic projection centered on the Prince Edward Islands, the location of the Vela incident Orthographic projection centered on the Prince Edward Islands, the location of the Vela incident

The Vela Incident (sometimes known as the South Atlantic Flash) was an as-yet unidentified flash of light detected by a United States Vela satellite on September 22, 1979. It has been speculated that the flash was the result of a nuclear weapons test; however, much information about the event is still classified. Contents [hide]

* 1 Detection * 2 Responsibility * 3 Subsequent developments * 4 See also * 5 Fiction * 6 References

[edit] Detection

The flash was detected on 22 September 1979, at 00:53 GMT, by a U. S. Vela satellite that was specifically developed to detect nuclear explosions. The satellite reported the characteristic double flash (a very fast and very bright flash, then a longer and less-bright one) of an atmospheric nuclear explosion of two to three kilotons, in the Indian Ocean near the Prince Edward Islands (South African dependencies) at 47° S 40° E. No known natural phenomenon causes this type of light flash. Vela-5A/B Satellites in Clean Room. The two satellites are separated after launch. Vela-5A/B Satellites in Clean Room. The two satellites are separated after launch.

There is some doubt as to whether the satellite's observations were accurate. Vela 6911 was one of a pair launched on 23 May 1969, more than ten years prior to the event, and the satellite was already two years past its design lifespan. It was known to have a failed electromagnetic pulse (EMP) sensor, and in addition had developed a fault (in July 1972) in its recording memory, but the fault had cleared itself by March 1978.

Initial assessments by the U.S. National Security Council in October 1979 and January 1980 were that the event was indeed a nuclear test, and that responsibility should be ascribed to South Africa.[1][2] Later, the Carter administration summoned a panel of experts headed by Jack Ruina to consider the reliability of the Vela 6911 data. Reporting in the summer of 1980, the panel concluded that the signal "was probably not from a nuclear explosion. Although we cannot rule out that this signal was of nuclear origin". The panel proposed that the satellite was in error and had perhaps been hit by a small meteorite. The fact that the explosion was only picked up by one of the satellites seems to support the panel's assertion. United States Air Force flights in the area soon after also failed to detect any sign of radiation.

Many doubt the panel's findings, arguing they were politically motivated. A considerable amount of evidence corroborating the nuclear hypothesis has been gathered. The Vela satellites had previously detected 41 atmospheric tests, each of which was subsequently confirmed by other means. There were some other data that seemed to confirm the explosion. Hydrophones operated by the US Navy detected a signal which was consistent with a small nuclear explosion on or slightly under the surface of the water near Prince Edward Islands. The radio telescope at Arecibo, Puerto Rico, also detected an anomalous traveling ionospheric disturbance at the same time. A test in Western Australia conducted a few months later found increased radiation levels.[3] The Los Alamos scientists who worked on the Vela program remain convinced that their satellite worked properly.

It has also been proposed that an explosion did occur, but was caused by a comet or other natural phenomenon, not a nuclear test.

[edit] Responsibility

The two primary suspects for the sources of an unexplained nuclear blast were Israel and South Africa, both of which had covert nuclear weapons programs at the time. A test by either Israel or South Africa would have been very awkward for the Carter administration. Israel was a close American ally, while the South African relationship was close but unpopular due to apartheid. Carter had worked hard on nonproliferation issues, and a vigorous response would have been required if it had been proven that either nation had conducted the test. This would have disrupted the negotiations underway over the Camp David Accords.

If a nuclear explosion did occur, it is uncertain who triggered it. There are difficulties with both the South African and Israeli hypotheses.

South Africa did have a nuclear weapons program at the time, and the