We explore the likelihood that early remains of Earth, Mars, and Venus have been preserved on the Moon in high enough concentrations to motivate a search mission. During the Late Heavy Bombardment, the inner planets experienced frequent large impacts. Material ejected by these impacts near the escape velocity would have had the potential to land and be preserved on the surface of the Moon. Such ejecta could yield information on the geochemical and biological state of early Earth, Mars and Venus. In order to determine whether the Moon has preserved enough ejecta to justify a search mission, we calculate the amount of Terran material incident on the Moon over its history by considering the distribution of ejecta launched from the Earth by large impacts. In addition, we make analogous estimates for Mars and Venus. We find, for a well mixed regolith, that the median surface abundance of Terran material is roughly 7 ppm, corresponding to a mass of approximately 20,000 kg of Terran material over a 10 x 10 square km area. Over the same area, the amount of material transferred from Venus is 1-30 kg, and material from Mars as much as 180 kg. Given that the amount of Terran material is substantial, we estimate the fraction of this material surviving impact with intact geochemical and biological tracers.
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机译：我们探索了地球，火星和金星的早期遗骸以足够高的浓度保存在月球上以激发搜寻任务的可能性。在后期重磅轰炸期间，内部行星频繁遭受重大撞击。这些撞击以接近逃逸速度的速度喷射出的物质可能会着陆并保留在月球表面。这样的喷射可以产生有关早期地球，火星和金星的地球化学和生物状态的信息。为了确定月球是否保留了足够的喷射量来证明搜索任务的正确性，我们考虑了大撞击从地球发射的喷射物的分布，计算了其历史上入射到月球上的人族物质的数量。此外，我们对火星和金星进行了类似的估算。对于混合良好的块石，我们发现Terran材料的中位数表面丰度约为7 ppm，相当于在10 x 10平方公里的区域中约有20,000 kg Terran材料的质量。在同一区域，从金星转移的物料量为1-30千克，从火星转移的物料量高达180千克。考虑到人族物质的数量可观，我们估算了在完整的地球化学和生物示踪剂的影响下该物质幸存下来的部分。
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