论文标题
来自常见的稀土冷凝及其随后的生长的地球胚和月亮的形成
Formation of embryos of the Earth and the Moon from the common rarefied condensation and their subsequent growth
论文作者
论文摘要
月球和地球的胚胎可能是由于共同的父母稀有冷凝的收缩而形成的。这种凝结所需的角动量可以在很大程度上获得两种产生父母凝结的稀疏冷凝水的碰撞。随后考虑到月球和地球的胚胎的随后生长，到达地球系统的当前角动量所需的总体胚胎总质量可能低于地球质量的0.01。为了使低月经丰度随着月球和地球的最初耗尽的胚胎的生长而复制，仅通过行星的积聚，月球胚胎的质量应大大增加1.3倍。然后由于无气培养基中行星的积累而导致的地球胚胎质量的最大增加为三倍，并且目前无法达到当前的陆地铁丰度。如果假定仅通过积聚固体行星（而没有从胚胎中弹出物质）而生长的胚胎，则很难在胚胎中的任何初始丰度下重现当前的月球和陆地铁丰度。为了复制当前的月球铁的丰度，从地球胚胎中弹出的物质量和进入月球胚胎中的物质的数量应该比直接在月球胚胎上的整体行星质量的总质量的总和要大的数量级，如果是从原始的胚胎中形成的。在与行星（和较小的物体）的多次碰撞中，可以从地球弹出大部分物质。
Embryos of the Moon and the Earth may have formed as a result of contraction of a common parental rarefied condensation. The required angular momentum of this condensation could largely be acquired in a collision of two rarefied condensations producing the parental condensation. With the subsequent growth of embryos of the Moon and the Earth taken into account, the total mass of as-formed embryos needed to reach the current angular momentum of the Earth-Moon system could be below 0.01 of the Earth mass. For the low lunar iron abundance to be reproduced with the growth of originally iron-depleted embryos of the Moon and the Earth just by the accretion of planetesimals, the mass of the lunar embryo should have increased by a factor of 1.3 at the most. The maximum increase in the mass of the Earth embryo due to the accumulation of planetesimals in a gas-free medium is then threefold, and the current terrestrial iron abundance is not attained. If the embryos are assumed to have grown just by accumulating solid planetesimals (without the ejection of matter from the embryos), it is hard to reproduce the current lunar and terrestrial iron abundances at any initial abundance in the embryos. For the current lunar iron abundance to be reproduced, the amount of matter ejected from the Earth embryo and infalling onto the Moon embryo should have been an order of magnitude larger than the sum of the overall mass of planetesimals infalling directly on the Moon embryo and the initial mass of the Moon embryo, which had formed from the parental condensation, if the original embryo had the same iron abundance as the planetesimals. The greater part of matter incorporated into the Moon embryo could be ejected from the Earth in its multiple collisions with planetesimals (and smaller bodies).
