Measuring Titan’s rapid orbital expansion combining Cassini radio science normal points and astrometry

Recent analyses of Titan’s orbital migration have yielded conflicting results regarding Saturn’s tidal dissipation (Q) at Titan’s frequency. While some studies reported a low Q consistent with resonance locking using independent radio science and astrometric datasets, subsequent work combining multiple mission datasets found a significantly higher Q, disagreeing notably with the earlier radio science findings. This study re-evaluates Titan’s migration by integrating Cassini radio science data, processed as normal points, with over a century of astrometric observations within a unified dynamical model using NOE software. Our combined analysis confirms the previously reported rapid migration rate and low Q, thus supporting the nonclassical dissipation mechanisms hypothesis.