A Five-Dimensional Diagnostic Scalar for Solar System Dynamics: Dual-Source Validation and Ranking Freeze

We introduce a dimensionless diagnostic scalar κ that compresses five classical orbital invariants---Hill-sphere mass factor, vis-viva deviation, semi-latus rectum, position-velocity synergy angle, and the instantaneous kinetic–potential partition---into a single cross-planetary comparable quantity through symmetric normalization and multiplicative coupling. On the standard orbital-dynamics benchmark of the circular restricted three-body problem, the resulting maps recover the co-orbital tadpole and horseshoe regions and trace the analytic resonance web (median offset 0.043 Jupiter radii from the nearest mean-motion resonance), computed without the variational-equation machinery of standard chaos indicators; a direct calibration against the Fast Lyapunov Indicator (FLI) delimits the diagnostic as a coherence and resonance tool orthogonal to chaos detection. Applied to the nine planets over 26 years of NASA JPL Horizons data (2000--2026, N=9649 days) through two physically independent ephemeris paths---direct orbital elements versus state-vector retro-propagation---the two versions agree to better than 0.11% in mean value, with temporal Pearson correlations r>0.998 for all planets. The κ ranking among the nine planets is essentially frozen across the observation window: five planets hold a single rank on all 9649 days, the remaining four exchange only adjacent ranks (Mercury--Pluto on 47 days, Venus--Mars on 57 days, ≲0.6% each), and the two data versions agree on 9642 of 9649 days (99.9%), exhibiting a clear mass--distance stratification. Three distinct reference-system strategies (virtual, fixed, and sliding ideal-body) all confirm this rigid immunity to data format and algorithmic path, with Neptune showing the largest---yet still insignificant---discrepancy. We explicitly note that this discrepancy is not associated with any true-anomaly boundary crossing: Neptune's true anomaly spans only 271°--328° during the observation window, far from the 0°/360° boundary. The results demonstrate that κ is robust to data format and computational path, and provide a continuous, cross-planetary diagnostic tool complementary to traditional orbital elements and Lyapunov-based stability indicators.