Tsar Bomba

Tsar Bomba was a Soviet thermonuclear bomb detonated over Novaya Zemlya on October 30, 1961. Its roughly 50-megaton yield made it the most powerful nuclear weapon ever tested.

Thermonuclear weapon: A nuclear weapon that derives most of its explosive energy from fusion reactions initiated by a fission explosion. Tsar Bomba was a staged thermonuclear weapon, not simply a larger fission bomb.
Soviet Union: A federal socialist state that existed across Eurasia from 1922 until its dissolution in 1991. The Soviet Union designed, built, and tested Tsar Bomba.
Novaya Zemlya: A Russian Arctic archipelago that served as a major Soviet nuclear test site. The bomb detonated above this remote archipelago.
Partial Test Ban Treaty: A 1963 treaty that prohibited nuclear weapon tests in the atmosphere, outer space, and underwater. The test preceded a treaty that curtailed atmospheric testing, though it was not its sole cause.
Teller–Ulam design: A thermonuclear weapon architecture that uses radiation from a primary stage to compress and ignite a secondary stage. Radiation implosion enabled the bomb’s enormous staged yield.
Nikita Khrushchev: The Soviet political leader who headed the Communist Party from 1953 to 1964. Khrushchev announced the planned giant bomb during the 1961 Communist Party Congress.
Operation Grapple: A series of British thermonuclear weapon tests conducted in the Pacific between 1957 and 1958. These British tests show another power developing thermonuclear weapons before 1961.
Nuclear arms race: The competition among states to build and improve nuclear arsenals. Tsar Bomba became a spectacular demonstration within the superpower competition over nuclear capability.
Nuclear fission: The splitting of heavy atomic nuclei, releasing energy and neutrons. A fission primary initiated the thermonuclear sequence.
Andrei Sakharov: A Soviet physicist who helped develop thermonuclear weapons and later became a human-rights advocate. Sakharov was a leading designer of the bomb and later criticized nuclear testing.

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