Short arc orbit determination and imminent impactors in the Gaia era

TL;DR

This paper introduces a new method for initial orbit determination of newly discovered asteroids, especially impactors, using systematic ranging to compute impact probabilities without prior assumptions, tested on past impactors and Gaia observations.

Contribution

The paper presents a novel systematic ranging approach for rapid impact probability assessment of asteroids with limited observational data.

Findings

Successfully applied to past impactors 2008 TC3 and 2014 AA

Effective on Gaia-observed objects with limited data

Provides rigorous impact probability estimates without prior assumptions

Abstract

Short-arc orbit determination is crucial when an asteroid is first discovered. In these cases usually the observations are so few that the differential correction procedure may not converge. We have developed an initial orbit computation method, based on the systematic ranging, an orbit determination techniques which systematically explores a raster in the topocentric range and range-rate space region inside the admissible region. We obtain a fully rigorous computation of the probability for the asteroid that could impact the Earth within few days from the discovery, without any a priori assumption. We test our method on the two past impactors 2008 TC3 and 2014 AA, on some very well known cases, and on two particular objects observed by the ESA Gaia mission.