Early in the Cold War, in studies known as Project GABRIEL and Project SUNSHINE, researchers in the United States, the United Kingdom, and Australia tried to determine how much nuclear fallout would be required to make the Earth uninhabitable.
冷戰早期，在知名於Project GABRIEL和Project SUNSHINE的研究中，美國、英國和澳洲的研究人員試圖測定多少原子塵會使地球不適宜居住。