经典碰撞模型是目前解释月球形成过程的最广为接受的假说，其要求一个约火星大小的撞击体Theia与吸积最后阶段的原始地球相撞，且月球主要来自撞击体Theia。然而关于撞击体对于月球质量贡献的百分比仍缺乏精确的制约。该研究采用地幔橄榄岩和科马提岩的高精度测量数据，用于重新评估硅酸盐全地球（BSE）的V同位素组成，相比之前的研究，新的数据表明δ⁵¹VBSE=-0.91‰±0.02‰ （2SE, n=18）。将其重新代入到地月双组分混合模型中，考虑了一个包含撞击前（原地球、Theia）和撞击后（地球、月球、逸出物质）成分的系统，得出现今月球中Theia的质量分数的最佳估计为M_Theia=0.8*M_Mars时的73%到M_Theia=0.45*M_Earth时的83%。这与先前的研究相比，降低了对Theia在月球形成中的贡献度约5%。这一结果为经典碰撞模型提供了更可靠的参数，有助于深化对月球形成过程的理解。

The classic giant impact model is currently the most widely accepted hypothesis for explaining the lunar formation process. It posits a collision between a proto-Earth in its late accretion stage and a Mars-sized impactor named Theia. According to this model, the majority of the Moon’s material is derived from Theia. However, there is still a lack of precise constraints on the contribution percentage of the impactor to the lunar mass. In this study, high-precision measurements of mantle peridotites and komatiites are employed to reevaluate the V isotope composition of the Bulk Silicate Earth (BSE). Unlike previous studies, the new data indicate δ51VBSE=-0.91±0.02‰（2SE, n=18）. We incorporated this into a two-component mixing model for the Earth-Moon system, considering a system with pre-impact (proto-Earth, Theia) and post-impact (Earth, Moon, escaping mass) components. The best estimate for the mass fraction of Theia in the present Moon ranges from 73% for M_Theia=0.8M_Mars to 83% for M_Theia=0.45M_Earth This represents a reduction of approximately 5% in Theia’s contribution compared to earlier studies. These findings provide more reliable parameters for the classic collision model, contributing to a deeper understanding of the lunar formation process.