Episodes of particle ejection from the surface of the active asteroid (101955) Bennu.

Autor:	Lauretta DS; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA. lauretta@orex.lpl.arizona.edu chergen@lpl.arizona.edu., Hergenrother CW; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA. lauretta@orex.lpl.arizona.edu chergen@lpl.arizona.edu., Chesley SR; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Leonard JM; KinetX Aerospace, Simi Valley, CA, USA., Pelgrift JY; KinetX Aerospace, Simi Valley, CA, USA., Adam CD; KinetX Aerospace, Simi Valley, CA, USA., Al Asad M; Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada., Antreasian PG; KinetX Aerospace, Simi Valley, CA, USA., Ballouz RL; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Becker KJ; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Bennett CA; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Bos BJ; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Bottke WF; Southwest Research Institute, Boulder, CO, USA., Brozović M; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Campins H; Department of Physics, University of Central Florida, Orlando, FL, USA., Connolly HC Jr; Department of Geology, Rowan University, Glassboro, NJ, USA.; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Daly MG; The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada., Davis AB; Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA., de León J; Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain., DellaGiustina DN; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.; Department of Geosciences, University of Arizona, Tucson, AZ, USA., Drouet d'Aubigny CY; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Dworkin JP; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Emery JP; Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA.; Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ, USA., Farnocchia D; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Glavin DP; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Golish DR; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Hartzell CM; Department of Aerospace Engineering, University of Maryland, College Park, MD, USA., Jacobson RA; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Jawin ER; Smithsonian Institution National Museum of Natural History, Washington, DC, USA., Jenniskens P; SETI (Search for Extraterrestrial Intelligence) Institute, Mountain View, CA, USA., Kidd JN Jr; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Lessac-Chenen EJ; KinetX Aerospace, Simi Valley, CA, USA., Li JY; Planetary Science Institute, Tucson, AZ, USA., Libourel G; Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France., Licandro J; Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain., Liounis AJ; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Maleszewski CK; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Manzoni C; London Stereoscopic Company, London, UK., May B; London Stereoscopic Company, London, UK., McCarthy LK; KinetX Aerospace, Simi Valley, CA, USA., McMahon JW; Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA., Michel P; Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France., Molaro JL; Planetary Science Institute, Tucson, AZ, USA., Moreau MC; NASA Goddard Space Flight Center, Greenbelt, MD, USA., Nelson DS; KinetX Aerospace, Simi Valley, CA, USA., Owen WM Jr; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Rizk B; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Roper HL; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Rozitis B; School of Physical Sciences, Open University, Milton Keynes, UK., Sahr EM; KinetX Aerospace, Simi Valley, CA, USA., Scheeres DJ; Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA., Seabrook JA; The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada., Selznick SH; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA., Takahashi Y; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA., Thuillet F; Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France., Tricarico P; Planetary Science Institute, Tucson, AZ, USA., Vokrouhlický D; Institute of Astronomy, Charles University, Prague, Czech Republic., Wolner CWV; Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
Jazyk:	angličtina
Zdroj:	Science (New York, N.Y.) [Science] 2019 Dec 06; Vol. 366 (6470).
DOI:	10.1126/science.aay3544
Abstrakt:	Active asteroids are those that show evidence of ongoing mass loss. We report repeated instances of particle ejection from the surface of (101955) Bennu, demonstrating that it is an active asteroid. The ejection events were imaged by the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer) spacecraft. For the three largest observed events, we estimated the ejected particle velocities and sizes, event times, source regions, and energies. We also determined the trajectories and photometric properties of several gravitationally bound particles that orbited temporarily in the Bennu environment. We consider multiple hypotheses for the mechanisms that lead to particle ejection for the largest events, including rotational disruption, electrostatic lofting, ice sublimation, phyllosilicate dehydration, meteoroid impacts, thermal stress fracturing, and secondary impacts. (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)
Databáze:	MEDLINE
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