Parameter-Free Time–Scalar Field Contributions to Galilean Moon Ephemerides: A Precision Residual Test Using the Io–Jupiter System

The Jovian satellite system is among the most over-constrained dynamical laboratories in celestial mechanics. Unlike exoplanetary systems, where orbital observablesare indirect and strongly degenerate with stellar variability and uncertain dissipation physics, the Galilean moons offer centuries of direct astrometric tracking, high-precision mutual-event timing, strong resonant structure, and independent spacecraft constraints on Jupiter’s gravity field. We propose a precision residual test of Time–Scalar Field Theory (TSFT) using the Io–Jupiter system, focusing not on naive precession measurements but on global ephemeris fits and inferred tidal dissipation parameters. A parameter-free TSFT exterior-tail acceleration enters the equations of motion as a small secular contribution that is observationally degenerate with tidal migration. The appropriate test is therefore whether inclusion of this term redistributes inferred dissipation—particularly Jovian and Io k2/Q—without degrading astrometric and mutual-event residuals. We provide explicit TSFT parameter values inherited from Mercury and S2 calibrations, order-of-magnitude estimates in the Jovian regime, a proof-of-concept N-body demonstration, falsification criteria based on standard information metrics, and a clear pathway to implementation within modern Galilean ephemerides.