Constraining the interiors of asteroids through close encounters
Name
2210.10754.pdf
Description
Accepted version
Size
6.88 MB
Format
Adobe PDF
Checksum (MD5)
80d2b7eec47ec926152eeca3003d88b6
Author(s)
Dinsmore, Jack T
de Wit, Julien
Date Issued
2022
Journal
Monthly Notices of the Royal Astronomical Society
Publisher
Oxford University Press (OUP)
Citation
Dinsmore, Jack T and de Wit, Julien. 2022. "Constraining the interiors of asteroids through close encounters." Monthly Notices of the Royal Astronomical Society.
Version
Author's final manuscript
Abstract
Abstract
Knowledge of the interior density distribution of an asteroid can reveal its composition and constrain its evolutionary history. However, most asteroid observational techniques are not sensitive to interior properties. We investigate the interior constraints accessible through monitoring variations in angular velocity during a close encounter. We derive the equations of motion for a rigid asteroid’s orientation and angular velocity to arbitrary order and use them to generate synthetic angular velocity data for a representative asteroid on a close Earth encounter. We develop a toolkit AIME (Asteroid Interior Mapping from Encounters) which reconstructs asteroid density distribution from these data, and we perform injection-retrieval tests on these synthetic data to assess AIME’s accuracy and precision. We also perform a sensitivity analysis to asteroid parameters (e.g. asteroid shape and orbital elements), observational set-up (e.g. measurement precision and cadence), and the mapping models used. We find that high precision in rotational period estimates (≲ 0.27 seconds) are necessary for each cadence, and that low perigees (≲ 18 Earth radii) are necessary to resolve large-scale density non-uniformities with uncertainties of $\sim 0.1{{\%}}$ of the local density under some models.
Knowledge of the interior density distribution of an asteroid can reveal its composition and constrain its evolutionary history. However, most asteroid observational techniques are not sensitive to interior properties. We investigate the interior constraints accessible through monitoring variations in angular velocity during a close encounter. We derive the equations of motion for a rigid asteroid’s orientation and angular velocity to arbitrary order and use them to generate synthetic angular velocity data for a representative asteroid on a close Earth encounter. We develop a toolkit AIME (Asteroid Interior Mapping from Encounters) which reconstructs asteroid density distribution from these data, and we perform injection-retrieval tests on these synthetic data to assess AIME’s accuracy and precision. We also perform a sensitivity analysis to asteroid parameters (e.g. asteroid shape and orbital elements), observational set-up (e.g. measurement precision and cadence), and the mapping models used. We find that high precision in rotational period estimates (≲ 0.27 seconds) are necessary for each cadence, and that low perigees (≲ 18 Earth radii) are necessary to resolve large-scale density non-uniformities with uncertainties of $\sim 0.1{{\%}}$ of the local density under some models.
MIT Department
Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1093/MNRAS/STAC2866
