Robert Oppenheimer’s moonshot project to build an atomic bomb in a top-secret lab in the New Mexico desert—and his lifelong qualms about the nuclear age he ushered in. Did the legendary ...

Three days after that blast, the United States detonated a second atomic bomb, nicknamed Fat Man, over the city of Nagasaki, some 185 miles (300 km) northeast of Hiroshima. The plutonium 239 bomb ...