In fact, the Palomares incident is not the only time a nuclear weapon has been misplaced. There have been at least 32 so-called “broken arrow” accidents – those involving these catastrophically destructive, earth-flattening devices – since 1950. In many cases, the weapons were dropped by mistake or jettisoned during an emergency, then later recovered. But three US bombs have gone missing altogether – they’re still out there to this day, lurking in swamps, fields and oceans across the planet.

“We mostly know about the American cases,” says Jeffrey Lewis, director of the East Asia Non-proliferation Program at the James Martin Center for Non-proliferation Studies, California. He explains that the full list only emerged when a summary prepared by the US Department of Defense was declassified in the 1980s.

Many occurred during the Cold War, when the nation teetered on the precipice of Mutually Assured Destruction (MAD) with the Soviet Union – and consequently kept airplanes armed with nuclear weapons in the sky at all times from 1960 to 1968, in an operation known as Chrome Dome.

“We don’t know as much about other countries. We don’t really know anything about the United Kingdom or France, or Russia or China,” says Lewis. “So I don’t think we have anything like a full accounting.”