Testing Gravitation in the Solar System with Radio Science experiments

TL;DR

This paper reviews Solar System gravity tests using radio science, introduces a new simulation software for analyzing signals, and applies it to the Cassini mission to constrain alternative gravity theories.

Contribution

It presents a novel software tool for simulating radio science signals from space-time metrics and applies it to real mission data to test gravity theories.

Findings

Constraints on parameters of alternative gravity theories

Validation of the simulation tool with Cassini data

Enhanced methods for Solar System gravity tests

Abstract

The laws of gravitation have been tested for a long time with steadily improving precision, leading at some moment of time to paradigmatic evolutions. Pursuing this continual effort is of great importance for science. In this communication, we focus on Solar System tests of gravity and more precisely on possible tests that can be performed with radio science observations (Range and Doppler). After briefly reviewing the current tests of gravitation at Solar System scales, we give motivations to continue such experiments. In order to obtain signature and estimate the amplitude of anomalous signals that could show up in radio science observables because of modified gravitational laws, we developed a new software that simulates Range/Doppler signals. We present this new tool that simulates radio science observables directly from the space-time metric. We apply this tool to the Cassini mission during its cruise from Jupiter to Saturn and derive constraints on the parameters entering alternative theories of gravity beyond the standard Parametrized Post Newtonian theory.