Nuclear bombing to protect Earth from asteroids? Why not, say scientists

Asteroid disruption: Asteroids have been a worrisome aspect for scientists for a long time, who worry about what would happen if another asteroid collision were to take place. The worries are not unfounded, since it was after all an asteroid attack that wiped dinosaurs off the face of the Earth. Hence, scientists have been looking at ways to deflect asteroids that could potentially collide with our planet and nudge it from its path before it reaches the Earth. However, for this, there needs to be a certain warning period during which measures can be implemented to nudge the asteroid. This has been in the works for a long time. Now, a research has said that if the warning time is not sufficient to undertake nudging measures, then asteroid disruption can be carried out with the help of a lot of energy which would lead to the asteroid turning into well-dispersed fragments.

The research, published in Acta Astronautica journal, has Lawrence Livermore National Laboratory (LLNL) former scholar Patrick King as lead author and it primarily looked at using nuclear energy to disrupt the asteroid when the warning time is not sufficient to stage a deflection. The research looked at the ways in which different asteroid orbits and different fragment velocity distributions would work together to impact the fragments. It used initial conditions from a hydrodynamics calculation, in which “a 1-Megaton-yield device was deployed a few meters off the surface of a Bennu-shaped, 100-meter diameter asteroid (1/5 the scale of Bennu)”.

The paper studied five asteroid orbits, and highlighted that for all of them, staging a disruption just two months before an asteroid’s Earth impact date could reduce the impacting mass by a factor of 1,000 or more, which translates to 99.9% of the asteroid’s mass missing the Earth. The research also stated that for a larger asteroid, while the dispersal would be less robust, it would still lead to 99% of the mass missing the Earth if the disruption is carried out six months before the Earth impact date.

However, this is not as easy as it seems. Lead author King said that a major challenge in assessing disruption as a strategy is needing to model all of the fragment orbits, which is much more complicated as compared to the modelling of a simple deflection. But he added that these challenges do need to be tackled or there at least needs to be an attempt to tackle them in order to assess disruption as a possible strategy.

King stated that his study looked at nuclear disruptions as a last resort and that scientists would prefer to stage deflections if time permits.