Dec 22, 2023 21:00:00

Lawrence Livermore National Laboratory develops a model to help verify the effectiveness of using nuclear weapons to protect the Earth from asteroid collisions in a planetary defense project

It is estimated that the amount of space debris that falls on Earth is approximately 5,000 tons per year. Most fall into harmless dust, but some, like

the meteorite that fell in Chelyabinsk, Russia, in 2013, can cause great damage to the surrounding area. For this reason, NASA is conducting an experiment in 2022 in which a spacecraft crashes into an asteroid to shift its orbit , but since there is a limit to the mass that can be launched into space, research continues into the use of nuclear weapons as an alternative method. I am.

X-Ray Energy Deposition Model for Simulating Asteroid Response to a Nuclear Planetary Defense Mitigation Mission - IOPscience
https://iopscience.iop.org/article/10.3847/PSJ/ad0838

New nuclear deflection simulations advance planetary defense against asteroid threats | Lawrence Livermore National Laboratory

https://www.llnl.gov/article/50716/new-nuclear-deflection-simulations-advance-planetary-defense-against-asteroid-threats

Some space debris collides not only with the Earth but also with other planets and debris in the solar system, and depending on the amount of energy released during the collision, there is a risk that a part of the Earth may have a devastating effect on the entire Earth. there is. However, if known in advance, it is possible to avoid this with modern technology, and a ``planetary defense'' campaign to detect near-Earth objects (NEOs) passing through Earth's orbit is underway worldwide. It's being expanded.

In 2005, the U.S. House of Representatives required NASA to locate 90% of NEOs large enough to cause regional devastation, but as of 2021, the detection rate has dropped to around 50%. I'm staying.

Also, small NEOs are not a threat, and it is thought that it was small NEOs that caused the Tunguska explosion in the past. However, small and slow-moving NEOs pose a serious challenge for early detection systems.

One of the methods devised to prevent asteroid collisions is ``DART'', which shifts the orbit of an asteroid. In September 2022, NASA conducted a demonstration experiment and succeeded in shifting the orbit of the asteroid Dimorphos.

NASA's ``experiment to shift the orbit by hitting an asteroid with a spacecraft'' was successful, and the image of the asteroid captured by the spacecraft just before the collision was also included - GIGAZINE

However, at the same time, in order to use kinetic energy to shift the asteroid's orbit like DART, the asteroid must be 100 to 200 meters in diameter, and the asteroid must be moved 10 years before the expected collision with the Earth. It turns out that we need to shift our trajectory.

Therefore, a more versatile and effective approach is to use a ``Nuclear Explosive Device (NED)''. According to simulations, if a 1Mt (megaton) NED is used at a distance of 15m to an asteroid with a diameter of 100m at least one month before impact, more than 90% of the material in the NEO will be destroyed without colliding with the Earth. About.

However, the problem is that simulations to predict the effectiveness of NED destruction missions require a variety of complex calculations.

To this end, Lawrence Livermore National Laboratory has produced a library of X-ray energy storage functions developed using radiation hydrodynamics codes. This model takes into account a variety of initial conditions and can be applied to a wide range of potential asteroid scenarios.

Megan Brooke Shull of the Planetary Defense Project said: ``In the event of a real-world emergency, this is a practical risk that could prevent an asteroid strike, protect critical infrastructure and save lives. 'High-fidelity simulation modeling is critical to providing information to decision makers.'