Strong Nongravitational Accelerations and the Potential for Misidentification of Near-Earth Objects

TL;DR

This study investigates how nongravitational accelerations affect the identification of near-Earth objects, revealing that high accelerations can hinder linking observations but current algorithms are generally robust.

Contribution

It introduces a new methodology for detecting unlinked NEO pairs affected by nongravitational accelerations and assesses the robustness of existing linking algorithms.

Findings

Nongravitational accelerations can cause position shifts of ~1000 arcsec between apparitions.

Current linking algorithms fail to connect tracklets with accelerations ≥10^{-8} au/d^2.

Existing algorithms are generally effective but may miss objects with large nongravitational accelerations.

Abstract

Nongravitational accelerations in the absence of observed activity have recently been identified on NEOs, opening the question of the prevalence of anisotropic mass-loss in the near-Earth environment. Motivated by the necessity of nongravitational accelerations to identify 2010 VL$_{65}$ and 2021 UA$_{12}$ as a single object, we investigate the problem of linking separate apparitions in the presence of nongravitational perturbations. We find that nongravitational accelerations on the order of $10^{-9}$ au/d$^2$ can lead to a change in plane-of-sky positions of $\sim10^3$ arcsec between apparitions. Moreover, we inject synthetic tracklets of hypothetical nongravitationally-accelerating NEOs into the Minor Planet Center orbit identification algorithms. We find that at large nongravitational accelerations ($|A_i|\geq10^{-8}$ au/d$^2$) these algorithms fail to link a significant fraction of these tracklets. We further show that if orbits can be determined for both apparitions, the tracklets will be linked regardless of nongravitational accelerations, although they may be linked to multiple objects. In order to aid in the identification and linkage of nongravitationally accelerating objects, we propose and test a new methodology to search for unlinked pairs. When applied to the current census of NEOs, we recover the previously identified case but identify no new linkages. We conclude that current linking algorithms are generally robust to nongravitational accelerations, but objects with large nongravitational accelerations may potentially be missed. While current algorithms are well-positioned for the anticipated increase in the census population from future survey missions, it may be possible to find objects with large nongravitational accelerations hidden in isolated tracklet pairs.