The lunar surface represents an exceptionally valuable archive of the long-termimpact environment of the Solar System. Due to the absence of an atmosphere,flowing water, and active plate tectonics, it preserves traces of bombardment oververy long timescales. Current observations show that lunar regolith is shapedprimarily by impacts of micrometeoroids with velocities in the usual range of tens ofkilometers per second. This article highlights an open question: if particlesoriginating in the broader galactic environment or in highly energetic astrophysicalprocesses may initially carry much higher velocities, why does the lunar surface notshow a clearer population of traces corresponding to systematic bombardment byprojectiles with significantly higher specific energy?The proposed hypothesis is based on the Dynamic Cosmic Medium Model (DKMM).Within this framework, space is not a physically active empty background, but aframework filled with a real dynamic cosmic medium whose state can influence thepropagation of matter and waves over long periods. Vacuum is not understood hereas a zero state or as the absence of medium, but as the equilibrium state of thedynamic cosmic medium with a positive base level. Interaction between the mediumand moving particles is not described as simple viscous friction, but as a long-termfiltering and retuning mechanism that limits the survival of extremely fastprojectiles along galactic trajectories and gradually incorporates them into the localdynamical regime of the environment.The lunar surface may therefore provide an indirect indication that the propagationof matter over cosmic distances is not perfectly neutral. The aim of the text is not toclaim that lunar microcraters by themselves prove the entire DKMM model, but toshow that their observed properties are consistent with the filtering role of anactive cosmic environment and that this direction deserves more systematicquantitative testing.
Aleš Hrůza (2026) studied this question.