On the Lense-Thirring test with the Mars Global Surveyor in the gravitational field of Mars

TL;DR

This paper analyzes the Mars Global Surveyor data to test frame-dragging effects predicted by general relativity, finding results consistent with theoretical expectations and addressing concerns about systematic errors.

Contribution

It presents a novel analysis of MGS orbit data to measure gravitomagnetic effects, demonstrating the absence of significant systematic errors in the out-of-plane component.

Findings

Measured orbit overlap differences consistent with general relativity

Systematic effects from gravitational field mismodeling are negligible

Non-gravitational forces do not significantly affect out-of-plane measurements

Abstract

I discuss some aspects of the recent test of frame-dragging performed by me by exploiting the Root-Mean-Square (RMS) orbit overlap differences of the out-of-plane component N of the orbit of the Mars Global Surveyor (MGS) spacecraft in the gravitational field of Mars. A linear fit of the full time series of the entire MGS data (4 February 1999-14 January 2005) yields a normalized slope 1.03 +/- 0.41 (with 95% confidence bounds). Other linear fits to different data sets confirm the agreement with general relativity. The huge systematic effects induced by the mismodeling in the martian gravitational field claimed by some authors are absent in the MGS out-of-plane record. The non-gravitational forces affect at the same level of the gravitomagnetic one the in-plane orbital components of MGS, not the out-of-plane one. Moreover, they experience high-frequency variations which does not matter in the present case in which secular effects are relevant.