Craters, boulders and regolith of (101955) Bennu indicative of an old and dynamic surface
Journal
Date Issued
2019
Author(s)
Walsh, K. J.
•
Jawin, E. R.
•
Ballouz, R. -L.
•
Barnouin, O. S.
•
Bierhaus, E. B.
•
Connolly, H. C.
•
Molaro, J. L.
•
McCoy, T. J.
•
Delbo', M.
•
Hartzell, C. M.
•
•
Schwartz, S. R.
•
Trang, D.
•
Asphaug, E.
•
Becker, K. J.
•
Beddingfield, C. B.
•
Bennett, C. A.
•
Bottke, W. F.
•
Burke, K. N.
•
Clark, B. C.
•
Daly, M. G.
•
Dellagiustina, D. N.
•
Dworkin, J. P.
•
Elder, C. M.
•
Golish, D. R.
•
Hildebrand, A. R.
•
Malhotra, R.
•
Marshall, J.
•
Michel, P.
•
Nolan, M. C.
•
Perry, M. E.
•
Rizk, B.
•
Ryan, A.
•
Sandford, S. A.
•
Scheeres, D. J.
•
Susorney, H. C. M.
•
Thuillet, F.
•
Lauretta, D. S.
•
Osiris-Rex Team
Abstract
Small, kilometre-sized near-Earth asteroids are expected to have young and frequently refreshed surfaces for two reasons: collisional disruptions are frequent in the main asteroid belt where they originate, and thermal or tidal processes act on them once they become near-Earth asteroids. Here we present early measurements of numerous large candidate impact craters on near-Earth asteroid (101955) Bennu by the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission, which indicate a surface that is between 100 million and 1 billion years old, predating Bennu's expected duration as a near-Earth asteroid. We also observe many fractured boulders, the morphology of which suggests an influence of impact or thermal processes over a considerable amount of time since the boulders were exposed at the surface. However, the surface also shows signs of more recent mass movement: clusters of boulders at topographic lows, a deficiency of small craters and infill of large craters. The oldest features likely record events from Bennu's time in the main asteroid belt.
Volume
12
Issue
4
Start page
242
Issn Identifier
1752-0894
Ads BibCode
2019NatGe..12..242W
Rights
open.access
File(s)![Thumbnail Image]()
![Thumbnail Image]()
Loading...
Name
Walsh_RDWG_Nature_V15.docx
Description
postprint
Size
56.13 KB
Format
Microsoft Word XML
Checksum (MD5)
156743f34c9ca437172f323522b94724
Loading...
Name
Walsh_et_al_2019_Craters_Boulders_Geology_Bennu.pdf
Description
[Administrators only]
Size
2.13 MB
Format
Adobe PDF
Checksum (MD5)
d44b8e93128679279579d8c316bebe1e