A new use for nuclear weapons: hunting rogue asteroids
A persistent campaign by weapons designers to develop a nuclear defense against extraterrestrial rocks slowly wins government support
When planetary scientist H. Jay Melosh attended a meeting between nuclear weapons designers from the United States and the former Soviet Union in May 1995, he was surprised by how eagerly the ex-Cold Warriors sought to work together against an unlikely but dangerous extraterrestrial threat: asteroids on a collision course with Earth.
After Edward Teller, father of the American hydrogen bomb, urged others in the session at Lawrence Livermore National Laboratory to consider building and orbiting large, new, nuclear weapons for planetary protection, some top Russian weaponeers in attendance voiced their support.
It was a really bizarre thing to see that these weapons designers were willing to work together to build the biggest bombs ever, said Melosh, a geophysicist at Purdue University and expert in space impacts who has an asteroid named after him.
Ever since, he has been pushing back against relying on nuclear bombs for the earths defense, arguing that a non-nuclear solution such as diverting the trajectory of asteroids by hitting them with battering rams is both possible and much less dangerous.
But Meloshs campaign suffered a setback last month when the Obama Administrations new Energy Secretary, Ernest Moniz, signed an agreement with the Russians that the Americans said could open the door to new collaboration between nuclear weapons scientists on asteroid defense. The topic has been particularly interesting to the Russians since an asteroid the size of a tour-bus exploded high in the skies of Russias Chelyabinsk region last February.
President Barack Obama has committed the United States to seeking a world without nuclear weapons, pushed for joint reductions in the U.S. and Russian nuclear arsenals and sought tighter security for nuclear explosives worldwide. When we fail to pursue peace, then it stays forever beyond our grasp, Obama said during his landmark speech in Prague in April 2009.
But in recent years, advocates of the use of nuclear weapons to counter space threats have been gaining ground. NASA is spending hundreds of thousands of dollars a year to study the idea, and the U.S. nuclear weapons laboratories are itching to work with the Russians on it. Moreover, weaponeers in both countries are citing the asteroid threat as a reason to hold onto or to build very large yield nuclear explosives, which have declining terrestrial justification.
There are a few impediments, such as the 1967 Outer Space Treaty signed by 129 countries, which prohibits deploying nuclear weapons in space, and other international treaties that bar nuclear weapons testing anywhere, including in space. Many planetary scientists are leery of the idea and some experts worry that radioactive debris from such a nuclear explosion could itself wreak havoc on Earth.
Outside the world of weaponeers, the idea can evoke humor, as exemplified by the kitschy 1998 Bruce Willis action film Armageddon, which shows a team of deep-sea oil drillers landing on an Earth-bound asteroid to implant a nuclear warhead that, at the last moment, separates the rock into neat halves that just miss Earth. Film critic Kenneth Turan called it sporadically watchable.
But in real life, Bong Wie, the director of Iowa State Universitys Asteroid Deflection Research Center, has a three-year, $600,000 grant from the National Aeronautics and Space Administration to design a hypervelocity nuclear interceptor system, basically an missile-borne, nuclear explosive fitted with a battering ram. The ram would separate from the bomb before impact, gouging a crater in the asteroid so the bomb could then blast it apart.
Wies plan is hardly Tellers grand vision of a space-based nuclear asteroid shield. He proposes using off-the-shelf land-based missiles and explosive warheads currently in the U.S. stockpile to intercept large, city-shattering asteroids that are less than about ten years from slamming into the Earth, when time is too short to nudge them into a new orbit.