When the countdown hit zero on September 23, 1992, the desert surface puffed up into the air, as if a giant balloon had inflated it from below.
It wasn’t a balloon. Scientists had exploded a nuclear device hundreds of meters below the Nevada desert, equivalent to thousands of tons of TNT. The ensuing fireball reached pressures and temperatures well beyond those in Earth’s core. Within milliseconds of the detonation, shock waves rammed outward. The rock melted, vaporized and fractured, leaving behind a cavity oozing with liquid radioactive rock that puddled on the cavity’s floor.
As the temperature and pressure abated, rocks collapsed into the cavity. The desert surface slumped,