Tracing the main belt origins of S-complex near-Earth objects: From space mission targets to meteorite sources
Abstract
Context. Space missions to near-Earth objects (NEOs) provide unique opportunities to study and characterise their physical and compositional properties. Interpreting these results requires knowledge of their provenance, i.e. their source family in the main asteroid belt. Aims. We aim to identify the family sources of six S-complex NEOs visited or soon to be visited by space missions, and to investigate the size-dependent orbital behaviour of the broader S-complex NEO population using the MITHNEOS dataset. Methods. We combine near-infrared spectral fitting with ordinary chondrite (OC) analogues reddened by a space-weathering model, using reduced χ2 minimisation, and cross-validation with probabilistic dynamical maps of the main NEO source families. Results. We identify LL6-7 chondrites and the Flora family for Eros, Itokawa, Apophis, and Torifune; LL3 chondrites and the Nysa family for Toutatis; L chondrites and the Massalia family for Didymos-Dimorphos. Where in situ observations exist (Itokawa and Eros), the classifications are consistent. Applied to the broader S-complex NEO population, the spectral classification and orbital properties distributions are broadly consistent with dynamical models. Accounting for observational biases, we find that at small diameters (≤100 m), the fractions of H- and L-type objects increase at the expense of LL6-7 types, with low-inclination orbits consistent with origins in the Massalia (L) and Koronis (H) families. Conclusions. Combining spectral fitting with OC analogues and dynamical probability maps robustly identifies the source families of individual NEOs. Below D∼100 m, the compositional distribution of S-complex NEOs approaches that of meteorite falls, providing direct observational evidence, based on spectroscopic measurements of S-complex NEOs, of the emergence of the source regions of OC meteorites.
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BibTeX
@misc{simon2026tracing,
title = {{Tracing the main belt origins of S-complex near-Earth objects: From space mission targets to meteorite sources}},
author = {P. N. Simon and P. Vernazza and M. Marsset and M. Brož and R. P. Binzel and F. DeMeo and C. A. Thomas and L. Jorda},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.07395},
eprint = {2610.07395},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.07395},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Tracing the main belt origins of S-complex near-Earth objects: From space mission targets to meteorite sources
AU - P. N. Simon
AU - P. Vernazza
AU - M. Marsset
AU - M. Brož
AU - R. P. Binzel
AU - F. DeMeo
AU - C. A. Thomas
AU - L. Jorda
PY - 2026
DA - 2026/10/05
PB - arXiv
DO - 10.48550/arxiv.2610.07395
UR - https://arxiv.org/abs/2610.07395
AB - Context. Space missions to near-Earth objects (NEOs) provide unique opportunities to study and characterise their physical and compositional properties. Interpreting these results requires knowledge of their provenance, i.e. their source family in the main asteroid belt. Aims. We aim to identify the family sources of six S-complex NEOs visited or soon to be visited by space missions, and to investigate the size-dependent orbital behaviour of the broader S-complex NEO population using the MITHNEOS dataset. Methods. We combine near-infrared spectral fitting with ordinary chondrite (OC) analogues reddened by a space-weathering model, using reduced χ^2 minimisation, and cross-validation with probabilistic dynamical maps of the main NEO source families. Results. We identify LL6-7 chondrites and the Flora family for Eros, Itokawa, Apophis, and Torifune; LL3 chondrites and the Nysa family for Toutatis; L chondrites and the Massalia family for Didymos-Dimorphos. Where in situ observations exist (Itokawa and Eros), the classifications are consistent. Applied to the broader S-complex NEO population, the spectral classification and orbital properties distributions are broadly consistent with dynamical models. Accounting for observational biases, we find that at small diameters (≤100 m), the fractions of H- and L-type objects increase at the expense of LL6-7 types, with low-inclination orbits consistent with origins in the Massalia (L) and Koronis (H) families. Conclusions. Combining spectral fitting with OC analogues and dynamical probability maps robustly identifies the source families of individual NEOs. Below D∼100 m, the compositional distribution of S-complex NEOs approaches that of meteorite falls, providing direct observational evidence, based on spectroscopic measurements of S-complex NEOs, of the emergence of the source regions of OC meteorites.
ER -