Evidence for Planet Nine with a 3,600-Year Period and 1 AU Perihelion as the Cause of Recurring Apocalypses.

A model of Planet Nine (P9) as a massive body (5 M⊕) in a highly eccentric retrograde orbit (e ≈ 0.994–0.996, q ≈ 1 AU, Q ≈ 400–500 AU, T ≈ 3600 yr), presumably captured from interstellar space. The model relies on the clustering of ETNO orbits by  the mass of the solar system near plane after chaotic scattering by P9. It also shows quasi-periodicity in climatic and cultural-historical markers (the Younger Dryas event, the Piora oscillation) consistent with a period of T ≈ 3600 yr. A historically confirmed possible observation of Planet Nine's perihelion passage of 1 AU has been established, supported by the exploratory LLM reconstruction of the comet's orbit observed in CE 60 for 180 days and documented in Chinese chronicles.Numerical modeling showed relative stability over a period of 1000,000 years.