Task: Explanation
Input (English): Paragraph: In November 2019, the Facebook page “Weird History” shared the following meme, which claimed that a four-megaton atomic bomb remained missing near Georgia — and that it might be live:Under an image of a Cold War-style bomb or missile (which was incidentally published to Wikipedia in 2008), text read:There’s been a four-megaton atomic bomb lost off the coast of Georgia since 1958 and no one really knows whether or not it’s active.The meme was shared a day ahead of the release of the fourth and final season of Man in the High Castle. A streaming and expanded adaptation of the 1962 Philip K. Dick novel of the same name, Man in the High Castle portrays an alternate history of Cold War-era America in which the Allies lost World War II.In the meme, the bomb is described as a “four-megaton atomic bomb.” Megatons are a unit of measurement used to express the force of hydrogen bombs; atomic bombs are typically quantified in kilotons:Thermonuclear bombs can be hundreds or even thousands of times more powerful than atomic bombs. The explosive yield of atomic bombs is measured in kilotons, each unit of which equals the explosive force of 1,000 tons of TNT. The explosive power of hydrogen bombs, by contrast, is frequently expressed in megatons, each unit of which equals the explosive force of 1,000,000 tons of TNT. Hydrogen bombs of more than 50 megatons have been detonated, but the explosive power of the weapons mounted on strategic missiles usually ranges from 100 kilotons to 1.5 megatons.To their credit, “Weird History” did include a status update along with a Facebook-formatted link:A Routine Training Mission Went Incredibly Wrong And Resulted In The Loss Of A Nuclear Weapon — rnkr.co/TybeeIslandThat link pointed to an entry on the listicle-heavy site Ranker, with a title similar to the text of the meme: “The US Air Force Lost A Nuclear Bomb Off The Coast Of Georgia In 1958 — And They Still Haven’t Found It.” It claimed:At around 1 am on February 5, 1958, Major Howard Richardson was piloting a B-47 Stratojet back to Homestead Air Force Base in Florida. The Major was cruising along at 38,000 feet following what he thought was a successful top-secret training mission – a simulated bombing in Virginia. Then, the situation went underwater – in every sense of the word.Unbeknownst to Richardson, the simulation was to feature one more pretend attack — from an F-86 Sabre jet fighter piloted by Lieutenant Clarence Stewart. That’s when disaster struck. […]The device is believed to have landed somewhere near Tybee Island – and the incident has since come to be known as the Tybee Island mid-air collision.One source cited by Ranker was a 2009 BBC article about the collision and its aftermath:More than 50 years after a 7,600lb (3,500kg) nuclear bomb was dropped in US waters following a mid-air military collision, the question of whether the missing weapon still poses a threat remains. […]Shortly after midnight on 5 February 1958, Howard Richardson was on a top-secret training flight for the US Strategic Air Command. It was the height of the Cold War and the young Major Richardson’s mission was to practise long-distance flights in his B-47 bomber in case he was ordered to fly from Homestead Air Force Base in Florida to any one of the targets the US had identified in Russia.Colonel Howard Richardson We thought maybe it was something from outer space, but it could only be another plane Colonel Howard Richardson The training was to be as realistic as possible, so on board was a single massive H-bomb – the nuclear weapon he might one day be instructed to drop to start World War III.As he cruised at 38,000 feet over North Carolina and Georgia, his plane was hit by another military aircraft, gouging a huge hole in the wing and knocking an engine almost off its mountings, leaving it hanging at a perilous angle … Colonel Richardson told me that the decision was instantaneous – and he still has no doubt it was the right thing to do.They would ditch their nuclear payload as soon as possible in order to lighten the aircraft for an emergency landing and also to eliminate the danger of an enormous explosion when they made their unsteady arrival at the nearest available runway.A May 2004 CBS article described the lost munition as an “H-bomb,” reporting on the area in which nuclear weapons enthusiast Derek Duke believed it sat in the waters off Savannah. Duke’s decades-dormant interest in the story was reinvigorated by internet chatter in the late 1990s, and he went looking with Geiger counters and a boat:There seems to be nothing special out here. But beneath the ocean floor off Savannah, an aluminum cylinder lies entombed in silt. It’s like an 11-foot-long bullet with a snub nose and four stubby fins. Written on it, its name: “No. 47782.” Enclosed in its metal skin: 400 pounds of conventional explosives and a quantity of bomb-grade uranium.No. 47782 is an H-bomb.A Mark 15, Mod 0 to be exact, one of the earliest thermonuclear devices developed by the United States. This is the kind whose mushroom clouds boiled in South Pacific tests. It was designed to be 100 times more powerful than the Hiroshima bomb.No. 47782 has rested off Savannah since Feb. 5, 1958.In some pieces the missing weapon was described as an atomic bomb or A-bomb, and in others, a hydrogen bomb or H-bomb. The explosive in question was the “first relatively light (3450 kg) thermonuclear bomb,” a Mark 15, in service from 1955 to 1965.CBS went on to describe conflicting information on whether the device posed a threat in its purported “watery grave”:Four months after Richardson’s [1958] accident, the Atomic Energy Commission changed [a] policy, banning the use of nuclear bombs during training exercises.As Duke was learning all of this, he turned up a copy of the Atomic Energy Commission receipt Richardson had signed. Written in ink near the top of the document was the word “simulated.” That, according to the Air Force, meant the bomb, containing 400 pounds of conventional explosives and an undisclosed amount of uranium, did not have a detonation capsule. Without it, there was no risk of a nuclear explosion.That was reassuring. And it might have been the end of the story if not for another document Duke soon acquired.This one was a letter, written in 1966 to the chairman of the Joint Committee on Atomic Energy, recounting the testimony of Assistant Defense Secretary Jack Howard before a 1966 congressional committee investigating the country’s missing and lost nuclear weapons.Howard, the letter says, testified there were four complete nuclear weapons, including detonation capsules, that were missing or lost. Among them: the bomb Richardson had dropped off the coast of Georgia.Reporters also contacted Richardson, the pilot, who maintained the sunken bomb was not active, and that if it was he would have known. In October 2004, the New York Times reported that the United States military began its first search for the missing bomb, but maintained it was “incapable” of detonation:It is the first time the military has sought signs of the 7,600-pound hydrogen bomb in the murky waters of Wassaw Sound since a crippled B-47 bomber dumped the Mark-15 bomb into the sea near Savannah in 1958.A team of 20 experts in nuclear weapons, gamma spectroscopy and underwater salvage confined their search to an area roughly the size of a football field, marked by buoys floating on the surface … The Air Force says the bomb is incapable of a nuclear explosion because it lacks the plutonium capsule needed to trigger one. Still, it contains about 400 pounds of conventional explosives and an undisclosed amount of uranium.The bomb was dropped into Wassaw Sound in February 1958 during a training flight when the bomber carrying it collided with a fighter jet.Four years later, a February 2009 NPR piece about the mystery of the missing nuke off Tybee Island began with the following clarification:Clarification: In the broadcast version of this report, NPR said that there was general agreement that the lost Savannah nuclear bomb contains significant quantities of uranium and plutonium. A 1966 Congressional document indicates that the bomb was a complete weapon containing both uranium and plutonium. But the Air Force and the former pilot of the plane, retired Col. Howard Richardson, deny the bomb contains plutonium.NPR reported that the Navy initially spent two months looking for the weapon, finally deciding that leaving it in its place was a better course of action than a recovery attempt:The Navy searched for the bomb for more than two months, but never found it, and today recommends it should remain in its resting place. In a 2001 report on the search and recovery of the bomb, the Air Force said that if the bomb is still intact, the risk associated with the spread of heavy metals is low. If [it is] left undisturbed, the explosive in the bomb poses no hazard, the report said. It went on to say that an “intact explosive would pose a serious explosion hazard to personnel and the environment if disturbed by a recovery attempt.”The original meme claimed that a “four-megaton atomic bomb” was “lost off the coast of Georgia” in 1958, and that “no one really knows whether or not it’s active.” On February 5 1958, an F-86 collided with the B-47 carrying a Mark 15 thermonuclear weapon, causing an emergency landing — during which the bomb was jettisoned, landing in the waters near Tybee Island, Georgia.Initial Naval searches for it were unsuccessful, and the missing nuke remained a subject of interest for more than half a decade; as the meme indicated, some dispute still surrounds its level of risk. Documents from the Cold War regarding whether the sunken munition contained both uranium and plutonium and whether it could be detonated contain conflicting information. Claim: Since 1958, a four-megaton atomic bomb has been missing off the coast of Georgia, and we don't know if it's active.
Output (English): A Four-Megaton Atomic Bomb Was Lost off Georgia’s Coast in 1958 (And No One Knows If It’s Active)