A unified phenomenological model for Solar System anomalies

Abstract

The improvement of ephemeris models to unprecedented levels of accuracy and the analysis of radiometric data for the planets, as well as Lunar laser ranging, have revealed some inconsistencies between the established theory and the observations. In the past decade, Krasinsky and Brumberg found a positive secular trend in the Astronomical Unit of a few meters per century. Some years before, a secular trend in the variation of the eccentricity of the orbit of the Moon had also been reported. This anomalous trend cannot, however, be explained within the context of the present state-of-the-art models for tidal dissipation and, although, the discrepancy has been reduced with the improvements in modeling it still remains significant at $2\sigma$ level. Moreover, there are also some anomalies that have been detected in spacecraft dynamics and, particularly, the so-called flyby anomaly for spacecrafts performing a slingshot manoeuvre around the Earth. Also the orbital decay and anomalous accelerations acting upon the geodynamic satellites are not completely understood with current orbital models. In this paper we suggest that all these effects are, perhaps, connected by means of an extra force proportional to the radial velocity and with latitude dependence. We show that such a phenomenological model could provide a common explanation to these and other phenomena.