On a correlation among azimuthal velocities and the flyby anomaly sign

TL;DR

This paper proposes a new gravitational model that introduces non-conservative forces, potentially explaining the flyby anomaly and its correlation with azimuthal velocity at perigee.

Contribution

It introduces a novel gravitational model accounting for non-conservative forces to explain flyby anomalies and their correlation with azimuthal velocities.

Findings

The model explains energy gains and losses during flybys.

A correlation between anomaly sign and azimuthal velocity is suggested.

Non-conservative forces may account for observed anomalies.

Abstract

Data of six flybys, those of Galileo I, Galileo II, NEAR, Cassini, Rosetta and Messenger were reported by Anderson et al \citep{Anderson}. Four of them: Galileo I, NEAR, Rosetta and Messenger gain Newtonian energy during the flyby transfer, while Galileo II and Cassini lose energy. This is, in both cases, a surprising anomaly since Newtonian forces derive from a potential and they are, therefore, conservative. We show here that the gravitational field of a rotating planet as derived from a new model introduces a non conservative force that gives a partial, but in our opinion satisfactory, explanation of these anomalies and suggests a correlation between the sign of the anomaly and the sign of the azimuthal velocity at perigee.