Michael Bay's 1998 disaster-thriller Armageddon needs no introduction at this point. The film is a cult-classic that endures on the strength of its rocking soundtrack (led by Aerosmith's classic "Don't Want to Miss A Thing"); a crazy ensemble cast of stars (including Bruce Willis, Billy Bob Thorton, Ben Affleck, Liv Tyler, Steve Buscemi, Owen Wilson, Jason Isaacs, William Fichter, and the late Michael Clarke Duncan); not to mention the crazy premise (a massive 'planet-killer' asteroid barreling towards Earth) that fans can never stop debating. However, nearly a quarter-century after Armageddon's release, science is endorsing the film's strategy for averting... our extinction!
In a new report featured on Science Alert, it seems that a "late-time small-body disruption" defense system of Earth is actually a viable strategy against incoming asteroids. Late-time small-body disruption is designed to use nuclear arms to blow "relatively small" asteroids into pieces when they are detected less than a year out from colliding with Earth; according to the latest reported calculations of such a scenario, late-time small-body disruption would be a "very effective" (if not complicated) means of protecting the planet.
According to physicist Patrick King of John Hopkins University Maryland: "One of the challenges in assessing disruption is that you need to model all of the fragment orbits, which is generally far more complicated than modeling a simple deflection. Nevertheless, we need to try to tackle these challenges if we want to assess disruption as a possible strategy."
As King indicates, this strategy is actually a bit more complicated than it may initially sound. Blowing up an asteroid still leaves the problem of what happens with all the pieces of debris that result from the explosion. There's also the (literally) bigger problem of what to do if an asteroid the size of the rock featured in the Armageddon movie starts tumbling our way. The study shows that late-time small-body disruption is still a way of averting disaster; a well-placed nuke blast could allegedly reduce the impact mass of a planet-killer asteroid to just 1 percent - provided the rock gets hit six months before it reaches us.
All that said, scientists are still looking at late-time small-body disruption as a last resort. The preferred strategy for deploying nukes in space is still deflection:
"We focused on studying 'late' disruptions, meaning that the impacting body is broken apart shortly before it impacts," says King. "When you have plenty of time – typically decade-long timescales – it is generally preferred that kinetic impactors are used to deflect the impacting body."
To that end, NASA and other similar agencies concerned with planetary defense measures are still focused on what they see as the more crucial first step: early detection, as well as improved methods for predicting and modeling the results and debris trajectory after impact:
"Our group continues to refine our modeling approaches for nuclear deflection and disruption, including ongoing improvements to X-ray energy deposition modeling, which sets the initial blowoff and shock conditions for a nuclear disruption problem," said physicist Megan Bruck Syal of the Lawrence Livermore National Laboratory.
The full study on late-time small-body disruption is available on Acta Astronautica.