Impatto imminente: Scienziati studiano la possibilità di usare bombe nucleari.

March 20, 2012 – SPACE –A well-placed nuclear explosion could actually save humanity from a big asteroid hurtling toward Earth, just like in the movies, a new study suggests. Scientists at Los Alamos National Laboratory, a United States Department of Energy facility in New Mexico, used a supercomputer to model nukes' anti-asteroid effectiveness. They attacked a 1,650-foot-long (500-meter) space rock with a 1-megaton nuclear weapon — about 50 times more powerful than the U.S. blast inflicted on Nagasaki, Japan, to help end World War II. The results were encouraging. “Ultimately this 1-megaton blast will disrupt all of the rocks in the rockpile of this asteroid, and if this were an Earth-crossing asteroid, would fully mitigate the hazard represented by the initial asteroid itself,” Los Alamos scientist Bob Weaversaid in a recent video released by the lab. In the 3-D modeling study, run on 32,000 processors of the Cielo supercomputer, the blast went off at the asteroid's surface. So the nuke likely wouldn't have to be deposited deep into a threatening space rock, a dangerous job Bruce Willis and his astronaut crew tackled in the 1998 film “Armageddon.” Weaver stressed that nuclear bombs would likely be deployed only as a last resort, if an impact loomed just months away. And other researchers caution that a nuclear blast might have negative side effects, such as sending a hail of many small space rocks toward Earth instead of a single big one. If humanity had more notice of an impending impact, there are several other asteroid defense strategies we might be able to employ, scientists have said. Discussions about asteroid deflection aren't just academic exercises. Huge impacts are a part of our planet's history; one wiped out the dinosaurs 65 million years ago, and it's just a matter of time before another big space rock lines Earth up in its sights, astronomers say.  http://www.space.com/14857-asteroid-nuclear-bomb-explosion-video.html