Remember the movie "Armageddon" -- the one starring Bruce Willis and Ben Affleck, where they flew a last-ditch mission to implant a nuclear device in a incoming asteroid to avert a planet-killing catastrophic event? That movie has been used as a prime example of how Hollywood sometimes overplays its dramatic hand when confronted with scientific truth. However, scientists at the Los Alamos National Laboratory have found that a well-placed nuclear device of sufficient strength just might be all that is needed to eliminate an impending threat.
According to the study, which tested the anti-asteroid effectiveness of nuclear weapons, a supercomputer -- called Cielo -- was used to run a model of a 1,650-foot-long (500-meter) asteroid, an object of conglomerated rock, being met with a 1-megaton nuclear weapon, a device yielding 50 times the amount of energy unleashed on Nagasaki during World War II.
"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," Bob Weaver stated in a video released by the Los Alamos lab.
In fact, in the supercomputer simulation of the mitigation event, the nuclear warhead was detonated near the surface of the hurtling asteroid and still managed to eliminate the space rock as a threat, unlike in the 1986 movie. In the film, the daring team of last-minute astronauts had to bury the device in order for it to be effective.
Scientists have long believed that detonating a nuclear warhead in or near an asteroid would only serve to break up the object, creating hundreds or even thousands of missiles with the ability to still impact the Earth. If some pieces of the asteroid remained large enough, the possibility remained that those pieces could cause even more damage to the Earth than if the object had been left to collide wholly intact.
The Los Alamos scientists also note that nuclear devices would most likely be a means of last resort mitigation. Various other methods of deflection would be attempted -- given enough warning, of course -- before something as potentially hazardous as a nuclear device would be used. They also admit that there still exists the possibility that exploding a nuclear warhead near or inside an asteroid could produce the undesirable results of a fractured object still headed for its original impact target.
But attempting to deflect an asteroid from impact might be in the near future. According to PhysOrg.com, an amateur team of astronomers discovered a near-Earth object (NEO), dubbed 2012 DA14, in February that has been calculated to have a revolution rate of 366.24 days. It also has an Earth-like orbit, passing in and out of the Earth's orbital path twice a year. In its next pass, it is expected to hurtle past the Earth inside of 15,000 miles, which is well below most satellites' orbits. And even though scientists have projected a near miss on its next fly-by, it is as yet unknown where it might travel after its passage, given that its trajectory will most likely be affected by the gravitational pull of both the Earth and Moon as it passes.
The NEO measured 2012 DA14 at approximately 160 feet in width. Depending upon its composition, it is a space rock that could potentially cause some major damage. However, it is not in the cataclysmic range, such as the Chicxulub asteroid that is believed to have caused the massive die-off of the dinosaurs. That projectile is estimated to have measured 6 miles in diameter.
The video from the Los Alamos National Laboratory follows.
(photo credit: Don Davis/NASA, Wikimedia Commons)