High precision astrometry of small solar system bodies

Abstract

The entire field of small solar system objects relies on the availability of accurate ephemerides: without them, the acquisition of any observation of a known moving object, with any observational technique, becomes impossible. A good ephemeris is the result of an accurate knowledge of the object’s orbit and its dynamical evolution, which in turn is based on astrometry, the direct measurement of an object’s position at given times. However, the value of quality astrometry and orbit determination extends beyond the basic production of accurate ephemerides. The study of the dynamics of these objects is intrinsically linked to key current research topics, such as: 1) The prediction and prevention of future impacts of near-Earth objects with our planet. 2) The study of peculiar populations of objects and their properties (e.g., Atiras, Main Belt Comets, Centaurs and TNOs, interstellar objects). 3) The study of non-gravitational effects on small bodies, and how they shed light on specific physical processes. 4) The study of the long-term dynamics of the Solar System, with its implications for the origin and evolution of planetary systems in general. 5) Indirectly, the possibility of enabling space missions to high-profile objects, both for scientific and planetary defense objectives. In recent years, our ability to extract accurate astrometry of these bodies has increased dramatically, thanks to the availability of the Gaia stellar catalog. Thanks to its exquisite accuracy, it is now possible to extract high-quality unbiased measurements, in turn improving our ability to model their orbits. New astrometric techniques, such as synthetic tracking, have also changed the way astrometric observations are scheduled and processed, and the hardware required for data acquisition and its analysis. In this paper, we will briefly discuss some of these key advances, and present some examples of how high-precision astrometry can be crucial to our understanding of the Solar System.