Astrophysics, abstract
astro-ph/0504367
From: Gary Page [view email]
Date (v1): Sun, 17 Apr 2005 17:04:48 GMT (32kb)
Date (revised v2): Sat, 1 Oct 2005 13:46:27 GMT (43kb)

Utilizing Minor Planets to Assess the Gravitational Field in the Outer Solar System

Authors: Gary L. Page, David S. Dixon, John F. Wallin

Categories: astro-ph

Comments: Added substantial new material dealing with ability to observed effects addressed in paper

The twin Pioneer spacecraft have been tracked for over thirty years as they headed out of the solar system. After passing a heliocentric distance of 20 AU, both exhibited a systematic error in their trajectories that can be interpreted as a constant acceleration towards the sun and that has come to be known as the Pioneer Effect.

Spacecraft systematics are its most likely explanation, but there have been no convincing arguments that that is the case. The alternative, that the Pioneer Effect represents a real phenomenon, is very appealing for many reasons. What is lacking is a means of measuring the effect, its variation, its potential anisotropies, and its region of influence.

We show that minor planets provide an observational vehicle for investigating the gravitational field in the outer solar system, and thus provide a means of measuring the Pioneer Effect and potentially to either support or refute its existence as a real phenomenon. Minor planets can be used for this purpose because they have a large mass and are large and bright enough to be observed for useful intervals.

Thus, even if the Pioneer Effect does not represent a new physical phenomenon, minor planets can be used to probe the gravitational field in the outer solar system. Since there are very few intermediate range tests of gravity at the multiple AU distance scale, this is a worthwhile endeavor in its own right. It might even be possible to differentiate between the predictions of alternative explanations for the Pioneer Effect.

http://arxiv.org/abs/astro-ph/0504367