Shape of (101955) Bennu indicative of a rubble pile with internal stiffness.

Autor: Barnouin OS; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Daly MG; The Centre for Research in Earth and Space Science, York University, Toronto, Ontario, Canada., Palmer EE; Planetary Science Institute, Tucson, AZ, USA., Gaskell RW; Planetary Science Institute, Tucson, AZ, USA., Weirich JR; Planetary Science Institute, Tucson, AZ, USA., Johnson CL; Planetary Science Institute, Tucson, AZ, USA.; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada., Asad MMA; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada., Roberts JH; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Perry ME; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Susorney HCM; Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, Canada., Daly RT; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Bierhaus EB; Lockheed Martin Space Systems Company, Denver, CO, USA., Seabrook JA; Planetary Science Institute, Tucson, AZ, USA., Espiritu RC; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Nair AH; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Nguyen L; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Neumann GA; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Ernst CM; The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA (olivier.barnouin@jhuapl.edu)., Boynton WV; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Nolan MC; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Adam CD; KinetX Aerospace, Inc. Simi Valley, CA, USA., Moreau MC; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Risk B; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., D'Aubigny CD; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Jawin ER; Smithsonian Institution National Museum of Natural History, Washington, DC, USA., Walsh KJ; Southwest Research Institute, Boulder, CO, USA., Michel P; Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France., Schwartz SR; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Ballouz RL; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Mazarico EM; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Scheeres DJ; Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA., McMahon J; Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA., Bottke W; Southwest Research Institute, Boulder, CO, USA., Sugita S; University of Tokyo, Tokyo, Japan., Hirata N; Aizu University, Aizu-Wakamatsu, Japan., Hirata N; Kobe University, Kobe, Japan., Watanabe S; Nagoya University, Nagoya, Japan.; Institute of Space and Astronautical Science, JAXA, Sagamihara, Japan., Burke KN; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., DellaGuistina DN; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Bennett CA; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Lauretta DS; Lunar Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
Jazyk: angličtina
Zdroj: Nature geoscience [Nat Geosci] 2019 Apr; Vol. 12 (4), pp. 247-252. Date of Electronic Publication: 2019 Mar 19.
DOI: 10.1038/s41561-019-0330-x
Abstrakt: The shapes of asteroids reflect interplay between their interior properties and the processes responsible for their formation and evolution as they journey through the Solar System. Prior to the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) mission, Earth-based radar imaging gave an overview of (101955) Bennu's shape. Here, we construct a high-resolution shape model from OSIRIS-REx images. We find that Bennu's top-like shape, considerable macroporosity, and prominent surface boulders suggest that it is a rubble pile. High-standing, north-south ridges that extend from pole to pole, many long grooves, and surface mass wasting indicate some low levels of internal friction and/or cohesion. Our shape model indicates that, similar to other top-shaped asteroids, Bennu formed by reaccumulation and underwent past periods of fast spin leading to its current shape. Today, Bennu might follow a different evolutionary pathway, with interior stiffness permitting surface cracking and mass wasting.
Databáze: MEDLINE