WASHINGTON -- When geophysicist H. Jay Melosh attended a meeting of U.S. and ex-Soviet nuclear weapons designers in May 1995, he was surprised by how eager the Cold Warriors were to work together against an unlikely but dangerous extraterrestrial threat: asteroids on a collision course with Earth.
After Edward Teller, the father of the hydrogen bomb, urged others meeting at the Lawrence Livermore National Laboratory in California to consider building and orbiting huge, new nuclear weapons for planetary protection, some top Russian weapons experts lent 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, an expert in space impacts who has an asteroid named after him.
Ever since, he has been pushing back against scientists who still support the nuclear option, arguing that a non-nuclear solution diverting asteroids by hitting them with battering rams is both possible and far less dangerous.
But Meloshs campaign suffered a setback last month when Energy Secretary Ernest Moniz signed an agreement with Russia that could open the door to new collaboration between nuclear weapons scientists in everything from plutonium-fueled reactors to lasers and explosives research. A Sept. 16 Department of Energy announcement cited defense from asteroids as one potential area of study.
President Barack Obama has committed the United States to seeking a world without nuclear weapons. But NASA is spending hundreds of thousands of dollars a year to study their use against asteroids, and the U.S. nuclear weapons labs appear to be itching to work with their Russian colleagues on the problem.
Moreover, weapons experts 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.
David Wright, co-director of the Union of Concerned Scientists Global Security Program, said he hoped any joint asteroid defense work would not become a jobs program for weapons scientists.
When youve got the weapons labs sort of pushing for this in the various countries, it starts to make me feel a little uneasy, he said. Which doesnt mean its not a legitimate thing to do, but you want to know its being done for legitimate reasons.
To some critics, the idea smacks of bad science fiction, something out of the 1998 Bruce Willis action film Armageddon, which shows a team of deep-sea oil drillers landing on an Earth-bound asteroid, planting a nuclear warhead and neatly blowing the rock in halves that just miss Earth.
Critics also note that depending on the nature of the work, it could run afoul of several international pacts, including the 1967 Outer Space Treaty signed by 129 countries that prohibits deploying nuclear weapons in space.
Some experts worry that radioactive debris from blasting an asteroid could itself wreak havoc on Earth.
Bong Wie, the director of Iowa State Universitys Asteroid Deflection Research Center, said he has a three-year, $600,000 grant from NASA to design a hypervelocity nuclear interceptor system, basically an ICBM-borne warhead 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 to bits.