月球巨撞击起源的最新模拟

Latest simulation to origin of the Moon by a giant impact

月球的起源与地球有密切关系。自1880年提出月球是从地球分裂出去的假说以来,科学家们提出了多种假说。近30多年来流行的是巨撞击假说,认为有颗称为忒伊亚(Theia)的星体撞击原地球,抛出的物质很快聚集形成地球的卫星——月球。行星形成过程的观测和理论研究确信地球吸积晚期经历过巨撞击,而月球的探测资料提供其起源的约束,计算机模拟方法的发展可以量化地跟踪撞击演变过程,得到符合约束的合理情况的可能范围。介绍三种最新的最佳模拟及其结果,虽然有所不同,但在很多关键问题上取得了重要进展,并得到一些普遍的结论。解决了地球和月球起源的基本问题,但还需要进一步研究遗留的或可能提出的新问题。

There is a close relationship between the origin of the moon and the earth. Since 1880 the hypothesis of the moon from the earth fission was proposed, many hypotheses have been put forward. Popular one in recent 30 years is giant impact hypothesis, thought that a planetary body called Theia hit the proto-earth, the ejecta soon aggregate to form the earth’s satellite, the moon. Observation and theoretical study for the formation of planets are sure that earth experienced a giant impact during its late accretion, and the detection data of the moon provided the constraints on its origin, the development of the computer simulation method can trace quantitatively the impact process, get the possible ranges of reasonable in line with the constraints. In this paper, the latest three best simulated results are introduced, although different among them, in many key issues they made important progress, some common conclusions may be got, to solve the basic problem of the origin of the earth and the moon, and more researches are needed to solve the left and new problems.