Reply to: Comment on "The Dominant Role of Energetic Ions in Solar Wind Interaction With the Moon" by Poppe.

In all kinetic simulations of the solar wind interaction with the moon, dayside absorption of the core solar wind protons results in the formation of a numerically unstable vacuum in the tail requiring a fix. In Omidi et al. (2019, https://doi.org/10.1029/2018JA026243) it was shown that replacing the vacuum with a cold plasma results in unacceptable magnetic fields when compared to observations. It was also demonstrated that when the presence of energetic ions in the solar wind is accounted for, the tail is no longer a vacuum but contains a low‐density plasma. In addition, the resulting magnetic fields are in excellent agreement with the observations including the presence of the compressional wake. Poppe (2019) shows results from the Amitis, which employs a different vacuum model and produces a magnetic field profile in the central tail that agrees with observations. However, the results do not account for the presence of low‐density plasma in the tail and the formation of the compressional wake. To explain these shortcomings, Poppe (2019) questions the existence of plasma in the tail and attributes the compressional wake to lunar crustal fields. Here we address the criticism of plasma observations and provide additional data from ARTEMIS spacecraft that demonstrates the compressional wake is an inherent part of the lunar tail structure. As such, the Amitis vacuum simulations do not capture the full physics of the interaction. In contrast, when the energetic protons are included in the model, all aspects of the lunar tail structure are accounted for. Key Points: Lunar tail contain low‐density plasmaThe compressional wake is an inherent part of the lunar tailEnergetic ions dominate the interaction [ABSTRACT FROM AUTHOR]