U.S. Takes Asteroid Threat Seriously

Some Nuclear Warheads, Once Set for Disassembly, Are Kept in Reserve

By John R. Emshwiller, WSJ
Sept. 30, 2014

Some U.S. nuclear-warhead components, scheduled for disassembly in the next year, have gotten at least a temporary new lease on life. The reason: possible use in defending the Earth against killer asteroids.

That bit of information was tucked deep inside a 67-page Government Accountability Office report on the National Nuclear Security Administration, which manages the U.S. atomic-weapons arsenal. The warhead components, containing highly enriched uranium, are being retained "pending a senior-level government evaluation of their use in planetary defense against earthbound asteroids," the April report said.

An NNSA spokesman declined to comment.

Government officials and space scientists say we aren't anywhere near a real-life replay of "Armageddon," the 1998 science-fiction extravaganza in which actor Bruce Willis and friends used a nuclear weapon to smash apart a giant asteroid hurtling toward Earth. While hundreds of asteroids with a diameter of about a kilometer or bigger—the size that could "produce global devastation," according to a 2010 National Research Council report—pass relatively near the Earth's orbit, none are expected to be a worry for at least 100 years and probably much longer, they say.

(More here.)