Bombardment history of the planets

越来越清楚的是，太阳系中的行星和星子（小行星和柯伊伯带天体）是共同进化的，行星迁移，星子带被耗尽，而行星上的轰击率在进化。这个项目将详细描述这种进化的一个关键阶段，与大约39亿年前的晚期重轰击（LHB）有关。在早期证据的基础上，这次调查将评估LHB和LHB后影响者的数量、大小和变化的影响率。严格的分析和数值模拟相结合，将确定LHB和LHB后撞击物的主要和次要来源，并提供LHB持续时间的上限和下限，它在地球、月球和其他类地行星上的强度，以及主小行星带枯竭的程度。这项研究有助于了解太阳系行星和小天体的动力学历史，特别是地球的轰击史，火星和水星的陨石坑地质年代学，以及主要小行星带的历史。它为重新研究月球增添了动力，也对太阳系外行星系统的研究产生了兴趣。在研究过程中获得的知识将被整合到马尔霍特拉博士的自然科学课程中，而陨石轰击和早期地球的历史具有广泛的公众和社区兴趣。

AST-0806828MalhotraIt is becoming increasingly clear that the planets and the planetesimals (the asteroids and Kuiper belt objects) in the solar system have co-evolved, such that the planets migrate and the planetesimal belts are depleted, while the bombardment rate on the planets evolves. This project will detail one crucial phase in this evolution, associated with the late heavy bombardment (LHB), some 3.9 billion years ago. Building on earlier evidence for the source and the mechanism of this event, this investigation will assess the number, sizes, and changing impact rates of the LHB and post-LHB impactors. Rigorous analysis and numerical modeling combined will identify the dominant and less dominant sources of the LHB and post-LHB impactors, and provide upper and lower limits on the duration of the LHB, its intensity on the Earth, Moon and other terrestrial planets, and the magnitude of depletion of the main asteroid belt.This research helps to understand the dynamical history of the planets and minor bodies of the solar system, especially the bombardment history of planet Earth, the crater-based geochronology of Mars and Mercury, and the history of the main asteroid belt. It adds impetus to renewed study of the Moon, and is also of interest to extra-solar planetary system studies. Knowledge gained during the study will be integrated into Dr Malhotra's natural sciences class, and meteorite bombardment and the history of early Earth have broad public and community interest.