This study contains predictions for mass spectrometry and plasma instrument measurements during upcoming Venus flybys of BepiColombo and Solar Orbiter and discusses the possibility of a phosphine detection with mass spectrometry in Venus’ upper atmosphere. The results extend the ones published previously in Gruchola et al. (2019), where predictions for the proposed ESA mission EnVision and the Venus flyby of JUICE were included. Both the Venus flyby of BepiColombo and the one of Solar Orbiter will take place in August 2021, only 1 day apart. BepiColombo, carrying the neutral mass gas spectrometer STROFIO, could probe the atmosphere around closest approach and obtain data on the thermal and hot neutral particle populations in the upper atmosphere. According to this study, the thermal hydrogen population as well as the hot species H, C, N and O, including isotopes, should be visible to STROFIO. Especially data on the abundance of the hot species would yield important insight into the planetary escape processes. The Solar Orbiter on the other hand carries the plasma instrument SWA-HIS, designed to measure the energetic solar wind ions. During its second Venus gravity assist it will traverse the magnetosheath, the region between bow shock and ion composition boundary, where in addition to the solar wind ions energetic planetary ions are present. The planetary pickup ions can be measured by SWA-HIS, providing important information on the outflow of planetary ions and the ionization processes in the upper atmosphere itself. The recent reports of phosphine in Venus’ cloud decks with an abundance of 20 ppb at 80 km probably overestimate the actual PH₃ abundance, as the data are currently being reanalyzed (Greaves et al., 2021). However, even with this upper limit of 20 ppb a phosphine detection with a mass spectrometer e.g. on-board ESA’s proposed EnVision mission, seems unlikely. To resolve the PH₃ peak and the ¹⁶O¹⁸O peak a mass resolution of almost 10’000 is required, and the PH₂D peak is masked by the Cl fragment peak of HCl. Furthermore, NGMS on-board Pioneer Venus with a mass resolution of around 440 did most likely not detect phosphine, as it scanned only a few masses in the mass range of interest where more abundant species than phosphine are present.

这项研究包含对即将到来的 BepiColombo 和太阳轨道器金星飞越期间质谱和等离子体仪器测量的预测，并讨论了在金星高层大气中使用质谱检测磷化氢的可能性。结果扩展了先前在 Gruchola 等人中发表的结果。（2019 年），其中包括对拟议的 ESA 任务 EnVision 和金星飞越 JUICE 的预测。BepiColombo 的金星飞越和太阳轨道器的金星飞越都将于 2021 年 8 月进行，相隔仅 1 天。BepiColombo 携带中性质谱仪 STROFIO，可以探测最近方法附近的大气，并获得高层大气中热和热中性粒子群的数据。根据这项研究，热氢种群以及热物种 H、C、N 和 O，包括同位素，应该对 STROFIO 可见。尤其是关于热物种丰度的数据将产生对行星逃逸过程的重要洞察。另一方面，太阳轨道器携带等离子体仪器 SWA-HIS，旨在测量高能太阳风离子。在其第二次金星重力辅助期间，它将穿越磁鞘，即弓形激波和离子组成边界之间的区域，除了太阳风离子外，还存在高能行星离子。SWA-HIS 可以测量行星拾取离子，提供有关行星离子流出和高层大气本身电离过程的重要信息。最近有关金星云层中磷化氢在 80 公里处的丰度为 20 ppb 的报道可能高估了实际的 PH 尤其是关于热物种丰度的数据将产生对行星逃逸过程的重要洞察。另一方面，太阳轨道器携带等离子体仪器 SWA-HIS，旨在测量高能太阳风离子。在其第二次金星重力辅助期间，它将穿越磁鞘，即弓形激波和离子组成边界之间的区域，除了太阳风离子外，还存在高能行星离子。行星拾取离子可以通过 SWA-HIS 测量，提供有关行星离子流出和高层大气本身电离过程的重要信息。最近有关金星云层中磷化氢在 80 公里处的丰度为 20 ppb 的报道可能高估了实际的 PH 尤其是关于热物种丰度的数据将产生对行星逃逸过程的重要洞察。另一方面，太阳轨道器携带等离子体仪器 SWA-HIS，旨在测量高能太阳风离子。在其第二次金星重力辅助期间，它将穿越磁鞘，即弓形激波和离子组成边界之间的区域，除了太阳风离子外，还存在高能行星离子。行星拾取离子可以通过 SWA-HIS 测量，提供有关行星离子流出和高层大气本身电离过程的重要信息。最近有关金星云层中磷化氢在 80 公里处的丰度为 20 ppb 的报道可能高估了实际的 PH₃丰度，因为目前正在重新分析数据（Greaves 等，2021）。然而，即使有 20 ppb 的上限，使用质谱仪（例如 ESA 提议的 EnVision 任务）进行磷化氢检测似乎不太可能。为了分辨 PH ₃峰和¹⁶ O ¹⁸ O 峰，需要接近 10'000 的质量分辨率，并且 PH ₂ D 峰被 HCl 的 Cl 碎片峰掩盖。此外，质量分辨率约为 440 的 NGMS 机载先锋金星很可能没有检测到膦，因为它只扫描了感兴趣质量范围内的少数质量，其中存在比膦更丰富的物种。