The U.S. government delayed the dismantling of some nuclear warhead components to protect against a foreign threat: asteroids. The nuclear component, called the canned subassembly (CSA), contains highly enriched uranium. Several of them were scheduled to be dismantled in 2015, but are now being kept until senior government officials can evaluate their usefulness in "planetary defense against earthbound asteroids," according to a Government Accountability Office document reported on first by the Wall Street Journal. It might sound like the National Nuclear Security Administration watched "Armageddon" one too many times, but it's not science fiction. NASA has provided funding to several researchers studying how nuclear devices could knock asteroids off course or blow them into pieces. In 2013, an asteroid exploded near Chelyabinsk, Russia, releasing the energy of nearly 500 kilotons of TNT — around 30 times the energy released by the bomb dropped on Hiroshima — and injuring more than a thousand people.
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