The impact of the Kuiper Belt Objects and of the asteroid ring on future high-precision relativistic Solar System tests

TL;DR

This paper assesses how Kuiper Belt Objects and asteroid rings could systematically bias high-precision tests of Newtonian and relativistic gravity in the Solar System, highlighting the need for careful consideration of these effects in future experiments.

Contribution

It provides a preliminary quantification of the gravitational influence of KBOs and asteroid rings on Solar System tests of gravity, emphasizing their potential to introduce systematic errors.

Findings

CKBOs induce about 1 m secular error in spacecraft orbit after one year.

The asteroid ring causes a 10 m/yr transverse perturbation on 1 AU orbits.

Biases in Mercury's perihelion precession due to these sources are significant relative to measurement precision.

Abstract

We preliminarily investigate the impact of the Kuiper Belt Objects (KBOs) and of the asteroid ring on some proposed high-precision tests of Newtonian and post-Newtonian gravity to be performed in the Solar System by means of spacecraft in heliocentric \approx 1 AU orbits and accurate orbit determination of some of the inner planets. It turns out that the Classical KBOSs (CKBOS), which amount to \approx 70% of the observed population of Trans-Neptunian bodies, induce a systematic secular error of about 1 m after one year in the transverse direction T of the orbit of a test particle orbiting at 1 AU from the Sun. For Mercury the ratios of the secular perihelion precessions induced by CKBOs to the ones induced by the general relativity and the solar oblateness J_2 amount to 6 10^-7 and 8 10^-4, respectively. The secular transverse perturbation induced on a \approx 1 AU orbit by the asteroid ring, which globally accounts for the action of the minor asteroids whose mass is about 5 10^-10 solar masses, is 10 m yr^-1; the bias on the relativistic and J_2 Mercury perihelion precessions is 6.1 10^-6 and 1 10^-2, respectively. Given the very ambitious goals of many expensive and complex missions aimed to testing gravitational theories to unprecedented levels of accuracy, these notes may suggest further and more accurate investigations of such sources of potentially insidious systematic bias.