近日，美国桑迪亚国家实验室的Nathan W. Moore及其研究团队取得一项新进展。经过不懈努力，他们利用百万焦耳级X射线脉冲模拟小行星偏转。相关研究成果已于2024年9月23日在国际知名学术期刊《自然—物理学》上发表。
该研究团队展示了利用桑迪亚国家实验室Z装置（一种脉冲功率装置）产生的稠密氩等离子体所发出的X射线脉冲，对小行星进行偏转模拟的过程。研究人员利用所谓的“X射线剪刀”将替代小行星物质置于自由空间，同时切断支撑并汽化目标表面。随后的爆炸在按比例缩小的小行星拦截任务中加速了模拟的小行星物质。
对于二氧化硅目标，约70米每秒的偏转速度与辐射流体动力学模型的预测相符。研究人员将这些结果按比例缩放至拟议的拦截器能量，并预测直径可达（4±1）公里的小行星可通过此机制被偏转，从而为未来的行星防御任务准备提供了一种可行的方法。
据悉，奇克苏鲁布小行星撞击引发了大规模灭绝、巨型海啸以及持续了约10万年的全球变暖。尽管美国国家航空航天局（NASA）最近的“双小行星重定向测试”任务表明，可以成功瞄准近地天体，但要使最危险的小行星偏转，所需的能量密度与核爆炸相当。然而，适合实际任务的目标却寥寥无几。
附：英文原文
Title: Simulation of asteroid deflection with a megajoule-class X-ray pulse
Author: Moore, Nathan W., Mesh, Mikhail, Sanchez, Jason J., Schaeuble, Marc-Andre, McCoy, Chad A., Aragon, Carlos R., Cochrane, Kyle R., Powell, Michael J., Root, Seth
Issue&Volume: 2024-09-23
Abstract: The Chicxulub asteroid impact triggered mass extinction, mega-tsunamis and a spell of global warming that lasted for around 100,000years. Although the recent Double Asteroid Redirection Test mission by NASA demonstrated that near-Earth objects can be successfully targeted, deflecting the most dangerous asteroids will require energy concentrations akin to nuclear explosions. However, targets suitable for practice missions are scarce. Here we demonstrate the simulation of asteroid deflection with an X-ray pulse from a dense argon plasma generated at the Z machine, a pulsed power device at Sandia National Laboratories. We use so-called X-ray scissors to place surrogate asteroidal material into free space, simultaneously severing supports and vapourizing the target surface. The ensuing explosion accelerates the mock asteroidal material in a scaled asteroid intercept mission. Deflection velocities of around 70ms–1 for silica targets agree with radiation-hydrodynamic model predictions. We scale these results to proposed interceptor energies and predict that asteroids up to a diameter of (4±1)km can be deflected with this mechanism, showing a viable way to prepare for future planetary defence missions.
DOI: 10.1038/s41567-024-02633-7
Source: https://www.nature.com/articles/s41567-024-02633-7