What if Mercury, Venus, Earth, and Mars all orbited at exactly 1 AU — Earth's distance from the Sun — evenly spaced 90 degrees apart like four beads on a ring? Real life forbids this: mutual gravitational perturbations would tug the planets apart within a few orbits, sending some inward and others outward. This scenario places all four worlds on a shared circular path while Jupiter, Saturn, Uranus, and Neptune remain in their real 1 January 2025 positions. The setup is a stress test for orbital stability: even seemingly orderly configurations are destroyed by the cumulative effect of close, repeated gravitational encounters among co-orbital bodies.