The Moon is the closest celestial body to Earth and the only extraterrestrial body from which humans have physically sampled, possessing the richest observational data. However, traditional lunar science still lacks first-principles explanations for several key issues: the lunar flattening (1/963) far exceeds the theoretical value (1/3000) explainable by rotational centrifugal force alone; 80% of moonquake energy originates from a single fixed source region; mascons are distributed in a ringlike pattern on the nearside with Oceanus Procellarum forming a central ”void”; the South Pole-Aitken (SPA) basin exhibits an impact angle of 30-45°; significant seismic azimuthal anisotropy exists in the shallow lunar crust; and the farside is significantly older than the nearside - a dichotomy confirmed by latest Chang’e-6 sample analysis. These anomalies require ad hoc assumptions under the traditional ”uniform sphere” or ”random impact” framework, lacking a unified underlying geometric explanation. Based on PFUSRC’s 45°Triple Coaxial Bicone global topology theory, this paper reinterprets the lunar internal structure as follows: a rigid bicone skeleton traverses the lunar interior; the waist ring is the region of maximum topological tension and material concentration; the two poles are narrowed channels where material is axially compressed; and a liquid interlayer (partially molten layer) fills the skeleton at specific depths. This model unifies the above observational anomalies under the intrinsic geometry of the bicone skeleton. This paper systematically compares observational data against model predictions across three modules: (1) Tidal response - lunar tidal Q-value (25-40), center-of-mass offset (2 km), liquid layer (asthenosphere below 1000 km), and single fixed source region (80% energy concentration) are highly consistent with bicone skeleton predictions, while contradicting uniform sphere predictions; (2) SPA impact - recent 3D numerical simulations show optimal impact angle of 30-45°, matching the 45°characteristic angle, with butterfly-shaped ejecta and a forbidden zone indicating directional stress propagation; (3) Mascon distribution - mascons are concentrated on the nearside in a ring pattern, Oceanus Procellarum forms a central void, and SPA has no mascon, consistent with bicone waist ring projection predictions. This paper further proposes testable quantitative predictions: the line connecting the SPA center and Oceanus Procellarum center should be at 45°to the lunar rotation axis; mascons should be distributed along the 45°conical projection; angular spacing between mascons should contain 12/11 harmonics; polar moonquakes should be nearly absent; and the nearside-farside age dichotomy should follow from the waist ring enrichment vs. polar depletion mechanism. Existing data show 12 predictions supporting the bicone skeleton hypothesis, 0 contradictions, and 5 awaiting precise computational verification. This study demonstrates that lunar flattening is not merely shaped by rotational centrifugal forces but that the Moon’s overall morphology is dominated by the geometric constraints of the internal 45°bicone topological skeleton. The Moon serves as an empirical test of the PFUSRC system on solid bodies (without a global liquid layer), together with stars (Paper 036) and Earth (Paper 037) constituting the ”Star-Planet-Satellite Unified Topology Theory,” proving that the 45°triple coaxial bicone is an inevitable geometric constraint in the process of matter aggregating from a discrete state into a structured state-a universal geometric framework for the structural evolution of celestial bodies. Furthermore, conical and biconical structures exhibit cross-scale universality in nature: the cone is the optimal force-transmitting structure, and the bicone constitutes the optimal closed stress system, features widely present in cosmic bodies, geological structures, life forms, and microscopic material structures.
Zhenmin Wang (Mon,) studied this question.