The Lense-Thirring effect in the Jovian system of the Galilean satellites and its measurability

TL;DR

This study assesses the feasibility of detecting the Lense-Thirring relativistic effect in the orbits of Jupiter's Galilean satellites using long-term optical observations, finding the effect's signature is largely obscured by data fitting.

Contribution

It provides a detailed analysis of the potential to measure the Lense-Thirring effect in the Jovian satellite system with current observational data and modeling techniques.

Findings

Lense-Thirring shifts are on the order of a few kilometers over a century.

Most of the relativistic signature is removed during initial condition fitting.

Residuals of the satellites' orbits are about 20 meters over 125 years.

Abstract

In this paper we investigate the possibility of measuring the post-Newtonian general relativistic gravitomagnetic Lense-Thirring effect in the Jovian system of its Galilean satellites Io, Europa, Ganymede and Callisto in view of recent developments in processing and modelling their optical observations spanning a large time interval (125 years). The present day best observations have an accuracy between several kilometers to few tens of kilometers, which is just the order of magnitude of the Lense-Thirring shifts of the orbits of the Galilean satellites over almost a century. From a comparison between analytical development and numerical integration it turns out that, unfortunately, most of the secular component of the gravitomagnetic signature is removed in the process of fitting the initial conditions. Indeed, an estimation of the magnitude of the Lense-Thirring effect in the ephemerides residuals is given; the resulting residuals have a maximum magnitude of 20 meters only (over 125 years).