The Open UniversitySkip to content
 

The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements

Scheeres, D. J.; McMahon, J. W.; French, A. S.; Brack, D. N.; Chesley, S. R.; Farnocchia, D.; Takahashi, Y.; Leonard, J. M.; Geeraert, J.; Page, B.; Antreasian, P.; Getzandanner, K.; Rowlands, D.; Mazarico, E. M.; Small, J.; Highsmith, D. E.; Moreau, M.; Emery, J. P.; Rozitis, Benjamin; Hirabayashi, M.; Sánchez, P.; Van wal, S.; Tricarico, P.; Ballouz, R.-L.; Johnson, C. L.; Al Asad, M. M.; Susorney, H. C. M.; Barnouin, O. S.; Daly, M. G.; Seabrook, J. A.; Gaskell, R. W.; Palmer, E. E.; Weirich, J. R.; Walsh, K. J.; Jawin, E. R.; Bierhaus, E. B.; Michel, P.; Bottke, W. F.; Nolan, M. C.; Connolly, H. C. and Lauretta, D. S. (2019). The dynamic geophysical environment of (101955) Bennu based on OSIRIS-REx measurements. Nature Astronomy, 3 pp. 352–361.

Full text available as:
Full text not publicly available (Accepted Manuscript)
Due to publisher licensing restrictions, this file is not available for public download until 19 September 2019
Click here to request a copy from the OU Author.
DOI (Digital Object Identifier) Link: https://doi.org/10.1038/s41550-019-0721-3
Google Scholar: Look up in Google Scholar

Abstract

The top-shaped morphology characteristic of asteroid (101955) Bennu, often found among fast-spinning asteroids and binary asteroid primaries, may have contributed substantially to binary asteroid formation. Yet a detailed geophysical analysis of this morphology for a fast-spinning asteroid has not been possible prior to the Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) mission. Combining the measured Bennu mass and shape obtained during the Preliminary Survey phase of the OSIRIS-REx mission, we find a notable transition in Bennu’s surface slopes within its rotational Roche lobe, defined as the region where material is energetically trapped to the surface. As the intersection of the rotational Roche lobe with Bennu’s surface has been most recently migrating towards its equator (given Bennu’s increasing spin rate), we infer that Bennu’s surface slopes have been changing across its surface within the last million years. We also find evidence for substantial density heterogeneity within this body, suggesting that its interior is a mixture of voids and boulders. The presence of such heterogeneity and Bennu’s top shape are consistent with spin-induced failure at some point in its past, although the manner of its failure cannot yet be determined. Future measurements by the OSIRIS-REx spacecraft will provide insight into and may resolve questions regarding the formation and evolution of Bennu’s top-shape morphology and its link to the formation of binary asteroids.

Item Type: Journal Item
Copyright Holders: 2019 Springer Nature
ISSN: 2397-3366
Academic Unit/School: Faculty of Science, Technology, Engineering and Mathematics (STEM) > Physical Sciences
Faculty of Science, Technology, Engineering and Mathematics (STEM)
Item ID: 60675
Depositing User: ORO Import
Date Deposited: 26 Apr 2019 10:41
Last Modified: 17 May 2019 03:08
URI: http://oro.open.ac.uk/id/eprint/60675
Share this page:

Metrics

Altmetrics from Altmetric

Citations from Dimensions

Actions (login may be required)

Policies | Disclaimer

© The Open University   contact the OU