History of Nuclear Testing: from Trinity to the Test Ban

Between 1945 and 1996 the world's nuclear powers carried out more than 2,000 nuclear test explosions — in deserts, on Pacific atolls, in the Arctic, underwater and deep underground. Their combined yield was equivalent to tens of thousands of Hiroshimas.

Trinity test fireball, 1945 — The Trinity fireball, 16 milliseconds after detonation on 16 July 1945 — the dawn of the nuclear age.

Trinity, 1945

The nuclear age began at 5:29 a.m. on 16 July 1945 in the New Mexico desert, when the world's first nuclear device — an implosion plutonium bomb nicknamed «the Gadget» — released about 20 kilotons at the Trinity site. Three weeks later the same technology was used over Hiroshima and Nagasaki.

Castle Romeo thermonuclear test — Castle Romeo (11 Mt), 1954 — one of the atmospheric thermonuclear tests of the era.

The atmospheric era: 1946–1962

After the war the United States moved testing to the Marshall Islands. In 1952 the first true thermonuclear device, Ivy Mike (10.4 Mt), erased the islet of Elugelab from the map. In 1954 the Castle Bravo shot ran away to 15 megatons — two and a half times its predicted yield — and its fallout contaminated inhabited atolls and a Japanese fishing boat, waking the world up to the danger of radioactive fallout.

The Soviet Union tested its first bomb in 1949, its first thermonuclear designs in 1953–55, and in 1961 detonated the 50-megaton Tsar Bomba over Novaya Zemlya — the largest explosion in human history. The United Kingdom (1952), France (1960) and China (1964) joined the club. The peak year was 1962, with more than 170 test explosions.

Underground: 1963–1996

Public alarm over strontium-90 in children's teeth helped produce the 1963 Limited Test Ban Treaty, which banned tests in the atmosphere, underwater and in space. Testing itself did not slow down — it simply moved underground, to the Nevada Test Site and the Semipalatinsk polygon in Kazakhstan, where more than three quarters of all nuclear tests took place. France continued atmospheric testing in Polynesia until 1974, China until 1980.

Nuclear tests by country chart — More than 2,000 tests were conducted, the great majority by the United States and the USSR.

The tally and the ban

United States — about 1,030 tests
Soviet Union — 715
France — 210
United Kingdom and China — 45 each
India, Pakistan (1998) and North Korea (2006–2017) — a handful each

The Comprehensive Nuclear-Test-Ban Treaty was opened for signature in 1996 and has been observed as a de facto moratorium by every nuclear power except North Korea, whose 2017 test — estimated well over 100 kilotons — remains the most recent nuclear explosion on Earth. You can recreate any of these historical shots in the simulator: the preset list includes Trinity, Hiroshima, Nagasaki, Ivy Mike, Castle Bravo and the Tsar Bomba.