Celestial orbits universally exhibit an elliptical shape, while ideal circular orbits are extremely rare in the real universe. Mainstream astrophysics often attributes elliptical orbits to gravitational perturbations in many-body systems, yet it overlooks the core role of inertial momentum conservation and fails to recognize the essential value of elliptical orbits in storing excess inertia, providing motion buffering, and enhancing anti-interference capability. Based on the mechanism of inertial momentum storage and release, this paper demonstrates that the elliptical orbit is the optimal form for celestial bodies to retain excess inertia and achieve dynamic equilibrium between gravitation and inertia. It emphatically expounds the buffering and reciprocating characteristics endowed by excess inertia and their key significance in resisting cosmic disturbances and preventing gravitational collapse. The study shows that circular orbits, lacking inertial margin and buffering space, have extremely weak anti-interference ability and are prone to collapse under tiny disturbances. They exist only as theoretical ideal models and cannot remain stable for a long time in the real universe. This paper further clarifies that the dissipation of inertial momentum is the fundamental cause of orbital collapse and the engulfment of celestial bodies by central objects, thus improving the interpretation of the physical nature of celestial orbit shapes.
Jiaqing Yan (Sat,) studied this question.