A common origin for dynamically associated near-Earth asteroid pairs

Abstract

identified and studied for over a decade, very few pair systems have been identified in the near-Earth asteroid population. We present data and analysis that supports the existence of two genetically related pairs in near-Earth space. The members of the individual systems, 2015 EE7 -2015 FP124 and 2017 SN16 -2018 RY7, are found to be of the same spectral taxonomic class, and both pairs are interpreted to have volatile-poor compositions. In conjunction with dynamical arguments, this suggests that these two systems formed via YORP spin-up and/or dissociation of a binary precursor. Backwards orbital integrations suggest a separation age of < 10 kyr for the pair 2017 SN16 -2018 RY7, making these objects amongst the youngest multiple asteroid systems known to date. A unique separation age was not realized for 2015 EE7 -2015 FP124 due to large uncertainties associated with these objects' orbits. Determining the ages of such young pairs is of great value for testing models of space weathering and asteroid spin-state evolution. As the NEO catalog continues to grow with current and future discovery surveys, it is expected that more NEO pairs will be found, thus providing an ideal laboratory for studying time dependent evolutionary processes that are relevant to asteroids throughout the Solar System.

Recent formation and likely cometary activity of near-Earth asteroid pair 2019 PR2 -- 2019 QR6

“…However, certain ancillary evidence supports the common origin scenario for this cluster, such as, highly similar spectra suggesting rare B-type taxonomic classifications for the two largest members of the cluster and the almost identical polarization properties of their surfaces (Devogèle et al, 2020). Moskovitz et al (2019) identified two probable near-Earth asteroid pairs 2015 EE7 -2015 FP124 (both members within the spectral taxonomic S-complex) and 2017 SN16 -2018 RY7 (both rare V-types) and they constrained their separation ages to < 10 4 yr.…”

“…Orbital similarity can be quantified with the Drummond D criterion (Drummond, 2000). For PR2 and QR6 D = 1.3 × 10 −4 , which is almost 30× smaller than the exceptional cases 2015 EE7 -2015 FP124 and 2017 SN16 -2018 RY7 identified by Moskovitz et al (2019). This makes them the two most similar orbits in the known near-Earth asteroid population of more than 25 000 objects (as of June 2021) according to analysis of Lowell Observatory's astorb 4 database of orbital elements.…”

(6478) Gault: physical characterization of an active main-belt asteroid

“…This pipeline has been fully vetted and been used to reduce hundreds of spectra (e.g. Devogèle et al 2019;Moskovitz et al 2019;Devogèle et al 2020). All images are first bias and flat field corrected using a series of 11 individual images to construct the master bias or flat.…”

Using Mars co-orbitals to estimate the importance of rotation-induced YORP break-up events in Earth co-orbital space

“…The existence of orbital clusters in NEO space resulting from a combination of mean-motion resonances and catastrophic disruptions (rotation-or impact-induced) has been explored in the literature (see e.g. Fu et al 2005;Schunová et al 2012;de la Fuente Marcos & de la Fuente Marcos 2016b;Moskovitz et al 2019;Jopek 2020) using the available but still limited observational evidence. The dynamics of objects part of the Arjuna asteroid belt is mostly controlled by Earth, but in some cases like that of 2020 CD 3 (Bolin et al 2020;de la Fuente Marcos & de la Fuente Marcos 2020;Fedorets et al 2020), the Moon also plays a non-negligible role.…”

“…Todd et al (2012a). On the other hand, a number of NEA pairs are suspected to come from YORP-induced rotational fissions (de la Fuente Marcos & de la Fuente Marcos 2019; Moskovitz et al 2019) and Earth coorbitals may also be experiencing these processes (see e.g. de la Fuente Marcos & de la Fuente Marcos 2018a).…”