By , Science News | March 27, 2025 sciencenews.org
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, forming a subsidence crater about 3 meters deep and wider than the length of a football field. Unknown to the scientists working on this test, named Divider, it would be the end of the line. Soon after, the United States halted nuclear testing.
Beginning with the first explosive test, known as Trinity, in 1945, more than 2,000 atomic blasts have rattled the globe. Today, that nuclear din has been largely silenced, thanks to the norms set by the Comprehensive Nuclear-Test-Ban Treaty, or CTBT, negotiated in the mid-1990s.
Only one nation — North Korea — has conducted a nuclear test this century. But researchers and policy makers are increasingly grappling with the possibility that the fragile quiet will soon be shattered.
Some in the United States have called for resuming testing, including a former national security adviser to President Donald Trump. Officials in the previous Trump administration considered testing, according to a 2020 Washington Post article. And there may be temptation in coming years. The United States is in the midst of a sweeping, decades-long overhaul of its aging nuclear arsenal…