Final and definitive version of the Triple Phase Transition (TPT) theory of lunar formation. A single internal driver — progressive Fe-Ni segregation — governs three coupled transitions (rheological, mechanical, magnetic) in the differentiating Hadean proto-Earth. No external impactor. No free parameter. Central prediction: seismic interfaces at 200–530 km depth, testable by Chang'e 7 (August 2026) and Artemis III (2028–2029). All hypotheses ranked. Limitations acknowledged (L1–L8). Falsification conditions defined.
Michel DEBAILLEUL (Thu,) studied this question.