An Alternative Explanation of the Orbital Expansion of Titan and Other Bodies in the Solar System

Recently it was found from the Cassini data that the mean recession speed of Titan from Saturn is \(v=11.3\pm 2.0\) cm/yr, which corresponds to a tidal quality factor of Saturn \(Q\cong 100\) while the standard estimate yields \(Q\geq 6\times 10^{4}\). It was assumed that such a large speed \(v\) is due to a resonance locking mechanism of five inner mid-sized moons of Saturn. In this paper, we show that an essential part of \(v\) may come from a local Hubble expansion, where the Hubble–Lemaître constant \(H_{0}\), recalculated to the Saturn–Titan distance \(D\), is 8.15 cm/(yr \(D\)). Our hypothesis is based on many other observations showing a slight expansion of the Solar system and also of our Galaxy at a rate comparable with \(H_{0}\). We demonstrate that the large disproportion in estimating the \(Q\) factor can be just caused by the local expansion effect.