Simulation testing is currently in full swing, as the astrophysical community looks forward to the so-called Double Asteroid Redirection Test (DART) mission, the first kinetic impact deflection probe to be conducted on an asteroid near the earth.
Researchers at the Lawrence Livermore National Laboratory (LLNL) in California have further advanced in their efforts to simulate how they could deflect celestial bodies potentially heading toward Earth (although the latter is highly unlikely), with the findings of their published study. in the new issue of the American Geophysical Union Earth and Space Science magazine.
The scientists conducted their tests by exploiting a smoothed-particle hydrodynamic code called Spheral to carry out a series of simulations that in turn helped researchers identify which models and material parameters are most important in accurately simulating impact scenarios. involving a potentially dangerous asteroid.
In addition to the resistance model, the team concluded that the simulation results are also highly dependent on strain models and material parameters.
The study separately identified vulnerabilities in the code that could help researchers who are currently designing a modeling plan for the Double Asteroid Redirection Test (DART) mission scheduled for 2021, the first demonstration of kinetic impact deviation in a near-Earth asteroid.
The accuracy of the codes was examined by comparing the simulation results with data from a 1991 laboratory experiment conducted at Kyoto University, where a hypervelocity projectile targeted a basalt sphere.
“This study suggests that the DART mission will impart less impulse transfer than previously calculated,” said Mike Owen, LLNL physicist, co-author of the article and developer of the Spheral code.
The team hopes the study results are useful, and the authors emphasize the importance of finding a solution to possible dilemmas:
“If there were an Earth-bound asteroid, underestimating the momentum transfer could mean the difference between a successful deflection mission and an impact. It is critical that we get the correct answer. Having real-world data to compare is like having the answer at the end of the book, ”Owen summarized.
The study’s lead author, LNL physicist Tané Remington, thinks the same thing, implying that prevention is better than cure:
“We are preparing for something that has a very low probability of happening in our lives, but a very high consequence if it happened,” said Tané Remington, assuming that time “will be the enemy if we see something.” we’re headed one day. “
“We may have a limited window to divert it, and we want to be sure that we know how to avoid the disaster. That is what this work is about, ”Remington explained.
With accounting of the results of computer simulations I can agree with numerous doubts about the expected effectiveness of the impact approach to asteroid deflection. Moreover, the “porosity of very loose aggregates” of all NEAs (through and through!) is not at all the “monolith porosity” used in the model. The detailed photos and probe impacting of asteroids Bennu and Ryugu revealed and confirmed their natural rubble-pile properties. Such an internal structure will completely prevent shock wave propagation and proper impulse transfer. The low-velocity ejection of asteroid material will most likely also not lead to a sufficient push for the same reasons – it will require escaping of many thousands of tons to achieve it. By the way, it seems strange the lack of preliminary conducting much cheaper laboratory/field experimental tests with compliance of the scale of masses and velocities. For example, a bullet shot at a very large “bag” with sand and stones of various sizes (but not basalt sphere!) and interferometric measurements of its possible displacement. It is important to emphasize that the reasons for these restrictions are fundamental and natural prohibitions, and not the technological problems that can be overcome during the development of the method. Therefore it is unlikely that the kinetic impact will work being neither effective nor scalable even to asteroids capable of country-wide destruction.