Investigating the space weathering of the Martian moon Phobos represents an important step toward understanding the development from its origin to its present‐day appearance. Depending on Phobos’ orbital position, its surface is continuously sputtered by the solar wind and planetary ions that originate in the Martian atmosphere. Based on Mars Atmosphere and Volatile Evolution measurements, it has been proposed that sputtering by planetary O⁺ and O₂⁺ ions dominates in the Martian tail region, where the planet mostly shadows Phobos from the solar wind. In these models, uncertainties for sputtering yield inputs still exist due to the lack of sufficient analog experiments. Therefore, sputtering measurements with O⁺, O₂⁺, C⁺, and CO₂⁺ ions between 1 and 5 keV were performed using augite samples as Phobos analogs. The experimental results for O⁺ irradiations show smaller mass changes than predicted by SDTrimSP simulations, which probably can be attributed to O implantation enabled by the Fe content of the target. Sputtering with O₂⁺ and CO₂⁺ in the low keV range shows no deviations in the sputtering yields attributable to molecular effects. Therefore, CO₂⁺ ions will most likely be negligible for the sputtering of Phobos according to the current understanding of ion fluxes on the Martian moon. Ultimately, our experiments suggest that the sputtering contribution on Phobos by O ions is about 50% smaller than previously assumed. This does not change the qualitative outcome from previous modeling stating that planetary O ions are by far the dominant sputtering contribution on Phobos in the Martian tail region.

中文翻译：

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磷矿空间风化的实验见解：原子和分子行星离子溅射的实验室研究

研究火星卫星火卫一的空间风化标志着朝着了解从起源到现在的发展方向迈出了重要的一步。根据火卫一的轨道位置，其表面会不断受到来自火星大气层的太阳风和行星离子的溅射。根据MAVEN的测量，有人提出在火星尾巴区域，行星O ⁺和O ₂ ⁺离子的溅射占主导地位，在该区域，行星主要遮挡了太阳风中的火卫一。在这些模型中，由于缺乏足够的模拟实验，溅射产量输入的不确定性仍然存在。因此，用O ⁺，O ₂ ⁺，C ^+进行溅射测量使用辉石样品作为Phobos类似物进行1到5 keV之间的CO ₂ ⁺离子。O ⁺辐照的实验结果表明，质量变化小于SDTrimSP模拟所预测的变化，这很可能归因于靶材中铁含量对O的注入。在低keV范围内用O ₂ ⁺和CO ₂ ⁺进行溅射时，没有发现可归因于分子效应的溅射产率偏差。因此，CO ₂ ⁺根据目前对火星月球上离子通量的了解，离子对于火卫一的溅射极有可能被忽略。最终，我们的实验表明，O离子对火卫一的溅射贡献比先前假定的小约50％。这并没有改变先前模型的定性结果，以前的模型表明行星O离子到目前为止是火星尾巴区域火卫一上的主要溅射贡献。