潜在威胁小行星碰撞防御的计算与分析

研究了采用碰撞的方式进行小行星防御的动力学问题。采用多面体模型来建立小行星的外形模型,以碎石堆模型来建立小行星的结构模型,计算了小行星受到与其密度和材质相同的球体高速碰撞过程和碰撞后的碎石分布。计算过程在考虑了小行星与碰撞球体的接触形变以及小行星内部组成碎石堆的接触形变条件下,计算了碎石堆内部的相互引力、法向接触力、切向静摩擦力、切向动摩擦力和滚动摩擦力矩。以小行星101955 Bennu(中文名贝努)为对象计算了潜在威胁小行星的碰撞防御过程的动力学行为。结果显示:采用高速碰撞的方法进行小行星防御可以有效地将小行星撞成大量碎小的石块,且该方法具有核爆的方法不可比拟的优势,即对空间环境无污染。

Calculation and Analysis of the Impact Defense to the Potentially Hazardous Asteroids

The dynamical problems of the asteroid defense are investigated by using the impact method. The polyhedron model isused to build the shape model of the asteroids, and the rubble-pile model is used to build the structure model of the asteroids. A sphere which has the same dense and material quality with the asteroid is assumed to impact to the asteroid, and the high velocity impact and the distribution of the rocks and rubbles after the impact are computed. Considering the contact deformation between the asteroid and the impact sphere, and the contact deformation inside the body of the asteroid among the rocks and rubbles which comprise the structure of the asteroid, the mutual gravitational force, the normal contact force, the tangential static frictional force, the tangential kinetic friction force, and the moment of rolling friction are calculated. Asteroid 101955 Bennu is used to calculate the dynamical behaviors of the impact defense of the potentially hazardous asteroids. The results show that the method of high velocity impact is useful for the defense of potentially hazardous asteroids, the asteroids can be crashed into a large number of rocks and rubble. The presented methodhas no pollution to the space environment. In this sense, the method is much better than the nuclear explosion method.