Ivy Mike
1952 CE.
Shown on the map at 11.237°, 162.196°.
Ivy Mike was the codename given to the first full-yield test of a multi-stage thermonuclear device, also known as the Teller–Ulam design. Ivy Mike was detonated on November 1, 1952, by the United States on the island of Elugelab in Enewetak Atoll, Pacific Proving Grounds, as part of Operation Ivy. Yielding 10.4 megatons of TNT, it dwarfed the previous largest test Greenhouse George (250 kilotons, 1951), and remains the fourth most powerful nuclear test by the US and tenth most powerful overall. The test was a key point in the nuclear arms race between the US and Soviet Union during the Cold War. US President Harry S. Truman ordered a full-scale hydrogen bomb program in January 1950, five months after the first Soviet nuclear test RDS-1. By March 1951, physicists Edward Teller and Stanisław Ulam produced a report detailing a two-stage design, where the X-rays from a fission bomb are directed toward radiation implosion of a secondary device containing fusion fuel.
Text from the Wikipedia article Ivy Mike, licensed CC BY-SA 4.0.