1. Internal rubble properties of asteroid (101955) Bennu
- Author
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Jay W. McMahon, Y. Takahashi, David D. Rowlands, Lydia C. Philpott, Michael C. Moreau, S. R. Chesley, Michael C. Nolan, Kevin J. Walsh, M. G. Daly, Eric Palmer, E. B. Bierhaus, A. S. French, Olivier S. Barnouin, Daniel J. Scheeres, Davide Farnocchia, Catherine L. Johnson, J. R. Weirich, J. A. Seabrook, Erwan Mazarico, D. E. Highsmith, Pasquale Tricarico, Peter G. Antreasian, Dante S. Lauretta, D. N. Brack, K. Getzandanner, J. M. Leonard, and Robert Gaskell more...
- Subjects
Earth and Planetary Astrophysics (astro-ph.EP) ,Near-Earth object ,Rubble ,FOS: Physical sciences ,Astronomy and Astrophysics ,engineering.material ,Geodesy ,Bulk density ,Gravity inversion ,Meteorite ,Gravitational field ,Space and Planetary Science ,Asteroid ,Void (composites) ,engineering ,Geology ,Astrophysics - Earth and Planetary Astrophysics - Abstract
Exploration of asteroid (101955) Bennu by the OSIRIS-REx mission has provided an in-depth look at this rubble-pile near-Earth asteroid. In particular, the measured gravity field and the detailed shape model of Bennu indicate significant heterogeneities in its interior structure, compatible with a lower density at its center. Here we combine gravity inversion methods with a statistical rubble-pile model to determine the density and size-frequency distribution (SFD) index of the rubble that constitutes Bennu. The best-fitting models indicate that the SFD of the interior is consistent with that observed on the surface, with a cumulative SFD index of approximately $-2.9$. The rubble bulk density is approximately $1.35$ g/cm$^3$, corresponding to a $12$% macro-porosity. We find the largest rubble particle to be approximately $145$ m, whereas the largest void is approximately $10$ m., 14 pages, 5 figures, accepted to Icarus more...
- Published
- 2021