A new study from John Hopkins University has demonstrated that attempting to blow up a giant impending asteroid with nuclear weapons will not work as gravity will simply force the debris to re-form. The experiment examined the physics of asteroid collisions in more detail than ever before. It concluded that whilst the initial impact does splinter the rock to some degree, in the longer term gravity will deviously bring all the pieces back together again.
The paper’s author Charles El Mir explained: “Our question was, how much energy does it take to actually destroy an asteroid and break it into pieces?
“We used to believe that the larger the object, the more easily it would break, because bigger objects are more likely to have flaws.
“Our findings, however, show that asteroids are stronger than we used to think and require more energy to be completely shattered.”
Their work received funding from the Solar System Exploration Research Virtual Institute run by NASA, the US federal space agency.
The team released two animated videos – the first of an initial impact, and the second demonstrating the unexpected reformation.
A press release explained: “In the first phase, after the asteroid was hit, millions of cracks formed and rippled throughout the asteroid, parts of the asteroid flowed like sand, and a crater was created.
“The new model showed that the entire asteroid is not broken by the impact, unlike what was previously thought.
Instead, the impacted asteroid had a large, damaged core that then exerted a strong gravitational pull on the fragments in the second phase of the simulation.
“The research team found that the end result of the impact was not just a ‘rubble pile’ — a collection of weak fragments loosely held together by gravity.
Instead, the impacted asteroid retained significant strength because it had not cracked completely, indicating that more energy would be needed to destroy asteroids.”
The misconception that nuclear weapons can be used to destroy asteroids is a popular one, proliferated largely by films such as ‘Armageddon’ and ‘Deep Impact.’