论文标题
修饰汞的成分和密度。
Modification of the composition and density of Mercury from late accretion
论文作者
论文摘要
后期积聚是一个强烈调节汞的地表地球形态和地球化学特征的过程。然而，撞击器的命运及其对汞表面的影响尚不清楚。使用蒙特卡洛和壁纹影响的分析方法，我们研究了汞后期积聚的物理和热力学结果。考虑到后期积聚中的不确定性，我们为以下参数制定了缩放定律，这是影响速度和后期积聚的总质量的函数：（1）地壳侵蚀的深度，（2）重新表面层面的程度，（3）造成影响物材料的质量增强质量。 Existing dynamical models indicate that Mercury experienced an intense impact bombardment (a total mass of $\sim 8 \times 10^{18} - 8 \times 10^{20}$ kg with a typical impact velocity of $30-40$ km s$^{-1}$) after $4.5$ Ga. With this, we find that late accretion could remove 50 m to 10 km of the early crust of Mercury, but the change就其核心竖孔比率而言，可以忽略不计。另外，如果汞最终从此类物体中获得，则可以更容易地去除早期太阳系中推定的分化行星的披风，并且各自的核心部分增加。尽管壁架在汞上擦除了较旧的地质表面记录，但我们表明，$ \ sim 40-50 $ wt％的外在材料（包括挥发性材料）可以作为晚期贴面异体植入在水星的表面上（$> 3 \ times 10^\ times 10^{18} {18} -1.6 -1.6 \ kg Int} $ 10^199} 199}大约一半的积聚撞击器的材料是蒸发的，其余的在撞击后完全融化。我们期望我们的理论结果与即将到来的汞表面观察（包括Bepicolombo任务）之间的进一步相互作用将使我们对汞的起源和进化有更好的了解。
Late accretion is a process that strongly modulated surface geomorphic and geochemical features of Mercury. Yet, the fate of the impactors and their effects on Mercury's surface through the bombardment epoch are not clear. Using Monte-Carlo and analytical approaches of cratering impacts, we investigate the physical and thermodynamical outcomes of late accretion on Mercury. Considering the uncertainties in late accretion, we develop scaling laws for the following parameters as a function of impact velocity and total mass of late accretion: (1) depth of crustal erosion, (2) the degree of resurfacing, and (3) mass accreted from impactor material. Existing dynamical models indicate that Mercury experienced an intense impact bombardment (a total mass of $\sim 8 \times 10^{18} - 8 \times 10^{20}$ kg with a typical impact velocity of $30-40$ km s$^{-1}$) after $4.5$ Ga. With this, we find that late accretion could remove 50 m to 10 km of the early crust of Mercury, but the change to its core-to-mantle ratio is negligible. Alternatively, the mantles of putative differentiated planetesimals in the early solar system could be more easily removed and their respective core fraction increased, if Mercury ultimately accreted from such objects. Although the cratering is notable for erasing the older geological surface records on Mercury, we show that $\sim 40-50$ wt% of the impactor's exogenic materials, including the volatile-bearing materials, can be heterogeneously implanted on Mercury's surface as a late veneer ($>3\times 10^{18}-1.6 \times 10^{19}$ kg in total). About half of the accreted impactor's materials are vaporized, and the rest is completely melted upon the impact. We expect that the further interplay between our theoretical results and forthcoming surface observations of Mercury, including the BepiColombo mission, will lead us to a better understanding of Mercury's origin and evolution.
