论文标题
月球探索是古代金星的调查
Lunar Exploration as a Probe of Ancient Venus
论文作者
论文摘要
一块古老的金星岩可能会限制那个星球的历史，并揭示海洋的过去。这样的样品可能会持续在月球上，这缺乏气氛和重要的地质活动。我们证明，如果金星的大气在任何一点都稀薄且与地球相似，那么小行星会影响潜在可检测到的金星表面材料转移到月球岩石上。金星相对于小行星碰撞的地球经历了增强的通量，这些碰撞被弹出（$ \ lyssim 40 $ gpa）表面材料。最初的发射条件以及与金星进化的射流轨迹的封闭式和共鸣变成了地球轨道。使用用于火山口喷射的分析模型和\ textit {n} - 体模拟，我们在月球上找到了超过$ 0.07 \％$的$ 0.07 \％$。如果金星在最近的3.5 Gyr中失去水，则月球矿石将含有高达0.2 ppm的金星材料。如果水损失了4个以上，则深度为0.3 ppm的巨型巨石是金星的起源。弹射器和月球之间约有一半的碰撞发生在$ \ Lessim6 $ km s $^{ - 1} $，流体动力模拟表明这足以避免重大的冲击改变。因此，对金星表面样品的恢复和同位素分析将在维纳斯（Venus）带有液体海洋和/或较低质量大气的置信度都高度置信度。对阿波罗任务中现有的月球样本中角膜碎屑的测试可能会立即解决。另外，即将到来的月球任务的雷果石表征可能会为维多利亚进化的这些基本问题提供答案。
An ancient Venusian rock could constrain that planet's history, and reveal the past existence of oceans. Such samples may persist on the Moon, which lacks an atmosphere and significant geological activity. We demonstrate that if Venus' atmosphere was at any point thin and similar to Earth's, then asteroid impacts transferred potentially detectable amounts of Venusian surface material to the Lunar regolith. Venus experiences an enhanced flux relative to Earth of asteroid collisions that eject lightly-shocked ($\lesssim 40$ GPa) surface material. Initial launch conditions plus close-encounters and resonances with Venus evolve ejecta trajectories into Earth-crossing orbits. Using analytic models for crater ejecta and \textit{N}-body simulations, we find more than $0.07\%$ of the ejecta lands on the Moon. The Lunar regolith will contain up to 0.2 ppm Venusian material if Venus lost its water in the last 3.5 Gyr. If water was lost more than 4 Gyr ago, 0.3 ppm of the deep megaregolith is of Venusian origin. About half of collisions between ejecta and the Moon occur at $\lesssim6$ km s$^{-1}$, which hydrodynamical simulations have indicated is sufficient to avoid significant shock alteration. Therefore, recovery and isotopic analyses of Venusian surface samples would determine with high confidence both whether and when Venus harbored liquid oceans and/or a lower-mass atmosphere. Tests on brecciated clasts in existing Lunar samples from Apollo missions may provide an immediate resolution. Alternatively, regolith characterization by upcoming Lunar missions may provide answers to these fundamental questions surrounding Venus' evolution.
