Overview
On September 22, 1979, the American Vela Hotel satellite detected a distinct "double flash" of light—the unmistakable signature of an atmospheric nuclear explosion—in the Indian Ocean between Africa and Antarctica. While the U.S. government officially suggested it may have been a "zoo event" caused by a micrometeoroid hitting the satellite, the intelligence community and most historians believe it was a low-yield nuclear test.
The Alleged Nuclear Partners
The primary theory posits that the test was a collaborative effort between Israel and South Africa. President Jimmy Carter noted in his personal diary a "growing belief" among his scientists that the Israelis had indeed conducted a nuclear test. Supporting evidence includes anomalous ionospheric disturbances measured in Puerto Rico and trace radioactive fallout detected in sheep thyroids in Australia shortly after the event.
Evidence of a Cover-Up
Critics allege the Carter administration orchestrated a cover-up to avoid the political fallout of admitting a close ally had violated the Limited Test Ban Treaty. To this day, several documents regarding the event remain classified by the United States.