One *** and two, code-named "Little Boy" were dropped in Hiroshima, Japan, and code-named "Fat Man" were dropped in Nagasaki, Japan.
After Germany surrendered in May 1945, many people in the United States who knew the inside story of the "Manhattan Project Area", including a large number of scientists engaged in this work led by physicist J. Frank, opposed the use of Atomic bombs bomb Japanese cities. At that time, the Japanese aggressors were severely hit by the Chinese people's long-term resistance war, and their strength was greatly weakened. The attacks by the United States and Britain in the Pacific region almost completely destroyed the Japanese navy, and the naval blockade made Japan's domestic supplies extremely scarce. When Japan's defeat was a foregone conclusion, the United States dropped the only two atomic bombs on Hiroshima and Nagasaki, Japan, on August 6 and 9.
1. On August 6, 1945, the US military carried out the first atomic bombing of Hiroshima. At 8:15 minutes and 17 seconds, the bomb bay door of the "Enola Gay" opened, and the atomic bomb "Little Boy" fell straight down from an altitude of 9,600 meters, only 17 seconds later than expected. At exactly 8:16, the air pressure detonator in "Little Boy" sent out a pulse signal, detonating the detonator, and quickly fired a "bullet" weighing about 25 kilograms of uranium block into the "bullseye" of a 35 kilogram uranium block. Two pieces of uranium 235 rolled into one and "Little Boy" exploded. The center projection point is over Jijima Hospital on 19th floor of Seiko Town, about 100 meters east of Aioi Bridge. According to a comprehensive evaluation in 1969, the explosion height was (580±15) meters.
2. On August 9, 1945, the US military prepared to drop bombs on the second target, Kokura, with Nagasaki as an alternative. At 10:58, Behan aimed at the intended bombing target, the Nagasaki City Center Stadium runway 2.5 kilometers north of Mitsubishi Heavy Industries' Nagasaki Shipyard, and dropped the atomic bomb "Fat Man". According to the U.S. Ordnance Survey L902 map, the core projection point is near Urakami Catholic Church, about 90 meters southeast of the center of the Matsuyama intersection, 129°51′56″4 east longitude, and 32°46′12″6 north latitude (i.e. Nagasaki At the Atomic Bomb Center Projection Monument in Peace Park).
Data source: Baidu entry Hiroshima atomic bomb incident