This storyoriginally appeared on Undarkand is part of theClimate Deskcollaboration. On March 23, 1971, the Soviet Union set off three Hiroshima-scale nuclear blasts deep underground in a remote region some 1,000 miles east of Moscow, ripping a massive crater in the earth. The goal was to demonstrate that nuclear explosions could be used to dig a canal connecting two rivers, altering their direction and bringing water to dry areas for agriculture.