1
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Walsh KJ, Ballouz RL, Jawin ER, Avdellidou C, Barnouin OS, Bennett CA, Bierhaus EB, Bos BJ, Cambioni S, Connolly HC, Delbo M, DellaGiustina DN, DeMartini J, Emery JP, Golish DR, Haas PC, Hergenrother CW, Ma H, Michel P, Nolan MC, Olds R, Rozitis B, Richardson DC, Rizk B, Ryan AJ, Sánchez P, Scheeres DJ, Schwartz SR, Selznick SH, Zhang Y, Lauretta DS. Near-zero cohesion and loose packing of Bennu's near subsurface revealed by spacecraft contact. Sci Adv 2022; 8:eabm6229. [PMID: 35857450 PMCID: PMC9262326 DOI: 10.1126/sciadv.abm6229] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
When the OSIRIS-REx spacecraft pressed its sample collection mechanism into the surface of Bennu, it provided a direct test of the poorly understood near-subsurface physical properties of rubble-pile asteroids, which consist of rock fragments at rest in microgravity. Here, we find that the forces measured by the spacecraft are best modeled as a granular bed with near-zero cohesion that is half as dense as the bulk asteroid. The low gravity of a small rubble-pile asteroid such as Bennu effectively weakens its near subsurface by not compressing the upper layers, thereby minimizing the influence of interparticle cohesion on surface geology. The underdensity and weak near subsurface should be global properties of Bennu and not localized to the contact point.
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Affiliation(s)
- Kevin J. Walsh
- Southwest Research Institute, Boulder, CO, USA
- Corresponding author.
| | - Ronald-Louis Ballouz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - Erica R. Jawin
- National Air and Space Museum, Smithsonian Institution, Washington, DC, USA
| | - Chrysa Avdellidou
- Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France
| | | | - Carina A. Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - Brent J. Bos
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Saverio Cambioni
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Harold C. Connolly
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
- Department of Geology, Rowan University, Glassboro, NJ, USA
| | - Marco Delbo
- Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France
| | | | - Joseph DeMartini
- Department of Astronomy, University of Maryland, College Park, MD, USA
| | - Joshua P. Emery
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ, USA
| | - Dathon R. Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | | | - Huikang Ma
- Lockheed Martin Space, Littleton, CO, USA
| | - Patrick Michel
- Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - Michael C. Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Ryan Olds
- Lockheed Martin Space, Littleton, CO, USA
| | - Benjamin Rozitis
- School of Physical Sciences, The Open University, Milton Keynes, UK
| | | | - Bashar Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Andrew J. Ryan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Paul Sánchez
- Colorado Center for Astrodynamics Research, University of Colorado Boulder, Boulder, CO, USA
| | - Daniel J. Scheeres
- Colorado Center for Astrodynamics Research, University of Colorado Boulder, Boulder, CO, USA
- Smead Aerospace Engineering Sciences Department, University of Colorado Boulder, Boulder, CO, USA
| | - Stephen R. Schwartz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
- Planetary Science Institute, Tucson, AZ, USA
| | | | - Yun Zhang
- Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - Dante S. Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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2
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Walsh KJ, Bierhaus EB, Lauretta DS, Nolan MC, Ballouz RL, Bennett CA, Jawin ER, Barnouin OS, Berry K, Burke KN, Brodbeck B, Burns R, Clark BC, Clark BE, Cambioni S, Connolly HC, Daly MG, Delbo M, DellaGiustina DN, Dworkin JP, Enos HL, Emery JP, Gay P, Golish DR, Hamilton VE, Hoover R, Lujan M, McCoy T, Mink RG, Moreau MC, Nolau J, Padilla J, Pajola M, Polit AT, Robbins SJ, Ryan AJ, Selznick SH, Stewart S, Wolner CWV. Assessing the Sampleability of Bennu's Surface for the OSIRIS-REx Asteroid Sample Return Mission. Space Sci Rev 2022; 218:20. [PMID: 35528719 PMCID: PMC9018658 DOI: 10.1007/s11214-022-00887-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/28/2022] [Indexed: 05/18/2023]
Abstract
NASA's first asteroid sample return mission, OSIRIS-REx, collected a sample from the surface of near-Earth asteroid Bennu in October 2020 and will deliver it to Earth in September 2023. Selecting a sample collection site on Bennu's surface was challenging due to the surprising lack of large ponded deposits of regolith particles exclusively fine enough ( ≤ 2 cm diameter) to be ingested by the spacecraft's Touch-and-Go Sample Acquisition Mechanism (TAGSAM). Here we describe the Sampleability Map of Bennu, which was constructed to aid in the selection of candidate sampling sites and to estimate the probability of collecting sufficient sample. "Sampleability" is a numeric score that expresses the compatibility of a given area's surface properties with the sampling mechanism. The algorithm that determines sampleability is a best fit functional form to an extensive suite of laboratory testing outcomes tracking the TAGSAM performance as a function of four observable properties of the target asteroid. The algorithm and testing were designed to measure and subsequently predict TAGSAM collection amounts as a function of the minimum particle size, maximum particle size, particle size frequency distribution, and the tilt of the TAGSAM head off the surface. The sampleability algorithm operated at two general scales, consistent with the resolution and coverage of data collected during the mission. The first scale was global and evaluated nearly the full surface. Due to Bennu's unexpected boulder coverage and lack of ponded regolith deposits, the global sampleability efforts relied heavily on additional strategies to find and characterize regions of interest based on quantifying and avoiding areas heavily covered by material too large to be collected. The second scale was site-specific and used higher-resolution data to predict collected mass at a given contact location. The rigorous sampleability assessments gave the mission confidence to select the best possible sample collection site and directly enabled successful collection of hundreds of grams of material.
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Affiliation(s)
| | | | - Dante S. Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Michael C. Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - Carina A. Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Erica R. Jawin
- National Air and Space Museum, Smithsonian Institution, Washington, DC USA
| | | | - Kevin Berry
- NASA Goddard Spaceflight Center, Greenbelt, MD USA
| | - Keara N. Burke
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Bella Brodbeck
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Rich Burns
- NASA Goddard Spaceflight Center, Greenbelt, MD USA
| | | | - Beth E. Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY USA
| | - Saverio Cambioni
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA USA
| | - Harold C. Connolly
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
- Department of Geology, Rowan University, Glassboro, NJ USA
| | - Michael G. Daly
- Centre for Research in Earth and Space Science, York University, Toronto, CA USA
| | - Marco Delbo
- CNRS-Observatoire de la Côte d’Azur, Nice, France
| | | | | | - Heather L. Enos
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - Pamela Gay
- University of Central Florida, Orlando, FL USA
| | - Dathon R. Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | | | - Michael Lujan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - Timothy McCoy
- Smithsonian Institution National Museum of Natural History, Washington, DC USA
| | | | | | | | - Jacob Padilla
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - Anjani T. Polit
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - Andrew J. Ryan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - Stephanie Stewart
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
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3
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Simon AA, Kaplan HH, Hamilton VE, Lauretta DS, Campins H, Emery JP, Barucci MA, DellaGiustina DN, Reuter DC, Sandford SA, Golish DR, Lim LF, Ryan A, Rozitis B, Bennett CA. Widespread carbon-bearing materials on near-Earth asteroid (101955) Bennu. Science 2020; 370:science.abc3522. [PMID: 33033153 DOI: 10.1126/science.abc3522] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 08/27/2020] [Indexed: 11/02/2022]
Abstract
Asteroid (101955) Bennu is a dark asteroid on an Earth-crossing orbit that is thought to have assembled from the fragments of an ancient collision. We use spatially resolved visible and near-infrared spectra of Bennu to investigate its surface properties and composition. In addition to a hydrated phyllosilicate band, we detect a ubiquitous 3.4-micrometer absorption feature, which we attribute to a mix of organic and carbonate materials. The shape and depth of this absorption feature vary across Bennu's surface, spanning the range seen among similar main-belt asteroids. The distribution of the absorption feature does not correlate with temperature, reflectance, spectral slope, or hydrated minerals, although some of those characteristics correlate with each other. The deepest 3.4-micrometer absorptions occur on individual boulders. The variations may be due to differences in abundance, recent exposure, or space weathering.
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Affiliation(s)
- Amy A Simon
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA.
| | | | | | - Dante S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Humberto Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - Joshua P Emery
- Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - M Antonietta Barucci
- Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, Université Paris Sciences et Lettres, Centre National de la Recherche Scientifique, Université de Paris, Sorbonne Université, Meudon, France
| | | | - Dennis C Reuter
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - Dathon R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Lucy F Lim
- Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Andrew Ryan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Benjamin Rozitis
- School of Physical Sciences, The Open University, Milton Keynes, UK
| | - Carina A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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4
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Kaplan HH, Lauretta DS, Simon AA, Hamilton VE, DellaGiustina DN, Golish DR, Reuter DC, Bennett CA, Burke KN, Campins H, Connolly HC, Dworkin JP, Emery JP, Glavin DP, Glotch TD, Hanna R, Ishimaru K, Jawin ER, McCoy TJ, Porter N, Sandford SA, Ferrone S, Clark BE, Li JY, Zou XD, Daly MG, Barnouin OS, Seabrook JA, Enos HL. Bright carbonate veins on asteroid (101955) Bennu: Implications for aqueous alteration history. Science 2020; 370:science.abc3557. [PMID: 33033155 DOI: 10.1126/science.abc3557] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 09/24/2020] [Indexed: 11/02/2022]
Abstract
The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu's parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.
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Affiliation(s)
- H H Kaplan
- NASA Goddard Space Flight Center, Greenbelt, MD, USA. .,Southwest Research Institute, Boulder, CO, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - A A Simon
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D C Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - K N Burke
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - H C Connolly
- Department of Geology, School of Earth and Environment, Rowan University, Glassboro, NJ, USA.,Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J P Dworkin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J P Emery
- Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - D P Glavin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - T D Glotch
- Department of Geosciences, Stony Brook University, Stony Brook, NY, USA
| | - R Hanna
- Jackson School of Geosciences, University of Texas, Austin, TX, USA
| | - K Ishimaru
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E R Jawin
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - T J McCoy
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - N Porter
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S A Sandford
- NASA Ames Research Center, Mountain View, CA, USA
| | - S Ferrone
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - B E Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - J-Y Li
- Planetary Science Institute, Tucson, AZ, USA
| | - X-D Zou
- Planetary Science Institute, Tucson, AZ, USA
| | - M G Daly
- Centre for Research in Earth and Space Science, York University, Toronto, Ontario, Canada
| | - O S Barnouin
- John Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - J A Seabrook
- Centre for Research in Earth and Space Science, York University, Toronto, Ontario, Canada
| | - H L Enos
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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5
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DellaGiustina DN, Burke KN, Walsh KJ, Smith PH, Golish DR, Bierhaus EB, Ballouz RL, Becker TL, Campins H, Tatsumi E, Yumoto K, Sugita S, Deshapriya JDP, Cloutis EA, Clark BE, Hendrix AR, Sen A, Al Asad MM, Daly MG, Applin DM, Avdellidou C, Barucci MA, Becker KJ, Bennett CA, Bottke WF, Brodbeck JI, Connolly HC, Delbo M, de Leon J, Drouet d'Aubigny CY, Edmundson KL, Fornasier S, Hamilton VE, Hasselmann PH, Hergenrother CW, Howell ES, Jawin ER, Kaplan HH, Le Corre L, Lim LF, Li JY, Michel P, Molaro JL, Nolan MC, Nolau J, Pajola M, Parkinson A, Popescu M, Porter NA, Rizk B, Rizos JL, Ryan AJ, Rozitis B, Shultz NK, Simon AA, Trang D, Van Auken RB, Wolner CWV, Lauretta DS. Variations in color and reflectance on the surface of asteroid (101955) Bennu. Science 2020; 370:science.abc3660. [PMID: 33033157 DOI: 10.1126/science.abc3660] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 09/24/2020] [Indexed: 11/02/2022]
Abstract
Visible-wavelength color and reflectance provide information about the geologic history of planetary surfaces. Here we present multispectral images (0.44 to 0.89 micrometers) of near-Earth asteroid (101955) Bennu. The surface has variable colors overlain on a moderately blue global terrain. Two primary boulder types are distinguishable by their reflectance and texture. Space weathering of Bennu surface materials does not simply progress from red to blue (or vice versa). Instead, freshly exposed, redder surfaces initially brighten in the near-ultraviolet region (i.e., become bluer at shorter wavelengths), then brighten in the visible to near-infrared region, leading to Bennu's moderately blue average color. Craters indicate that the time scale of these color changes is ~105 years. We attribute the reflectance and color variation to a combination of primordial heterogeneity and varying exposure ages.
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Affiliation(s)
- D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA. .,Department of Geosciences, University of Arizona, Tucson, AZ, USA
| | - K N Burke
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - K J Walsh
- Southwest Research Institute, Boulder, CO, USA
| | - P H Smith
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - R-L Ballouz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - T L Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - E Tatsumi
- Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain.,Department of Earth and Planetary Science, University of Tokyo, Tokyo, 113-0033, Japan
| | - K Yumoto
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, 113-0033, Japan
| | - S Sugita
- Department of Earth and Planetary Science, University of Tokyo, Tokyo, 113-0033, Japan
| | - J D Prasanna Deshapriya
- LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique), Observatoire de Paris, Université PSL (Paris Sciences & Lettres), CNRS (Centre National de la Recherche Scientifique), Université de Paris, Sorbonne Université, 92195 Meudon, France
| | - E A Cloutis
- Department of Geography, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - B E Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - A R Hendrix
- Planetary Science Institute, Tucson, AZ, USA
| | - A Sen
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - M M Al Asad
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
| | - M G Daly
- The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada
| | - D M Applin
- Department of Geography, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - C Avdellidou
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - M A Barucci
- LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique), Observatoire de Paris, Université PSL (Paris Sciences & Lettres), CNRS (Centre National de la Recherche Scientifique), Université de Paris, Sorbonne Université, 92195 Meudon, France
| | - K J Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - W F Bottke
- Southwest Research Institute, Boulder, CO, USA
| | - J I Brodbeck
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H C Connolly
- Department of Geology, Rowan University, Glassboro, NJ, USA
| | - M Delbo
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - J de Leon
- Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | | | - K L Edmundson
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S Fornasier
- LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique), Observatoire de Paris, Université PSL (Paris Sciences & Lettres), CNRS (Centre National de la Recherche Scientifique), Université de Paris, Sorbonne Université, 92195 Meudon, France.,Institut Universitaire de France (IUF), 1 rue Descartes, 75231 Paris CEDEX 05, France
| | | | - P H Hasselmann
- LESIA (Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique), Observatoire de Paris, Université PSL (Paris Sciences & Lettres), CNRS (Centre National de la Recherche Scientifique), Université de Paris, Sorbonne Université, 92195 Meudon, France
| | - C W Hergenrother
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E S Howell
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E R Jawin
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - H H Kaplan
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - L Le Corre
- Planetary Science Institute, Tucson, AZ, USA
| | - L F Lim
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - J Y Li
- Planetary Science Institute, Tucson, AZ, USA
| | - P Michel
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - J L Molaro
- Planetary Science Institute, Tucson, AZ, USA
| | - M C Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J Nolau
- Lockheed Martin Space, Littleton, CO, USA
| | - M Pajola
- Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Padova, Padua, Italy
| | - A Parkinson
- Department of Geography, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - M Popescu
- Astronomical Institute of the Romanian Academy, Bucharest, Romania.,Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | - N A Porter
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J L Rizos
- Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | - A J Ryan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B Rozitis
- The School of Physical Sciences, The Open University, Milton Keynes, UK
| | - N K Shultz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - A A Simon
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - D Trang
- University of Hawai'i at Mānoa, Hawai'i Institute of Geophysics and Planetology, Honolulu, HI, USA
| | - R B Van Auken
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C W V Wolner
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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6
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Rozitis B, Ryan AJ, Emery JP, Christensen PR, Hamilton VE, Simon AA, Reuter DC, Al Asad M, Ballouz RL, Bandfield JL, Barnouin OS, Bennett CA, Bernacki M, Burke KN, Cambioni S, Clark BE, Daly MG, Delbo M, DellaGiustina DN, Elder CM, Hanna RD, Haberle CW, Howell ES, Golish DR, Jawin ER, Kaplan HH, Lim LF, Molaro JL, Munoz DP, Nolan MC, Rizk B, Siegler MA, Susorney HCM, Walsh KJ, Lauretta DS. Asteroid (101955) Bennu's weak boulders and thermally anomalous equator. Sci Adv 2020; 6:eabc3699. [PMID: 33033037 PMCID: PMC7544501 DOI: 10.1126/sciadv.abc3699] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 09/09/2020] [Indexed: 05/18/2023]
Abstract
Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high-thermal inertia band at Bennu's equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.
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Affiliation(s)
- B Rozitis
- School of Physical Sciences, The Open University, Milton Keynes, UK.
| | - A J Ryan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J P Emery
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ, USA
| | - P R Christensen
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | | | - A A Simon
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, USA
| | - D C Reuter
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, USA
| | - M Al Asad
- Department of Earth, Atmospheric, and Ocean Science, University of British Columbia, Vancouver, BC, Canada
| | - R-L Ballouz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - O S Barnouin
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M Bernacki
- Mines ParisTech, PSL Research University, CEMEF-Centre de mise en forme des matériaux, Sophia Antipolis Cedex, France
| | - K N Burke
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S Cambioni
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B E Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - M G Daly
- The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada
| | - M Delbo
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS, Laboratoire Lagrange, Nice, France
| | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C M Elder
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - R D Hanna
- Jackson School of Geosciences, University of Texas, Austin, TX, USA
| | - C W Haberle
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ, USA
| | - E S Howell
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E R Jawin
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - H H Kaplan
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, USA
| | - L F Lim
- NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, USA
| | - J L Molaro
- Planetary Science Institute, Tucson, AZ, USA
| | - D Pino Munoz
- Mines ParisTech, PSL Research University, CEMEF-Centre de mise en forme des matériaux, Sophia Antipolis Cedex, France
| | - M C Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M A Siegler
- Planetary Science Institute, Tucson, AZ, USA
| | - H C M Susorney
- School of Earth Sciences, University of Bristol, Bristol, UK
| | - K J Walsh
- Southwest Research Institute, Boulder, CO, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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7
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Molaro JL, Walsh KJ, Jawin ER, Ballouz RL, Bennett CA, DellaGiustina DN, Golish DR, Drouet d'Aubigny C, Rizk B, Schwartz SR, Hanna RD, Martel SJ, Pajola M, Campins H, Ryan AJ, Bottke WF, Lauretta DS. In situ evidence of thermally induced rock breakdown widespread on Bennu's surface. Nat Commun 2020; 11:2913. [PMID: 32518333 PMCID: PMC7283247 DOI: 10.1038/s41467-020-16528-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Accepted: 05/04/2020] [Indexed: 11/13/2022] Open
Abstract
Rock breakdown due to diurnal thermal cycling has been hypothesized to drive boulder degradation and regolith production on airless bodies. Numerous studies have invoked its importance in driving landscape evolution, yet morphological features produced by thermal fracture processes have never been definitively observed on an airless body, or any surface where other weathering mechanisms may be ruled out. The Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission provides an opportunity to search for evidence of thermal breakdown and assess its significance on asteroid surfaces. Here we show boulder morphologies observed on Bennu that are consistent with terrestrial observations and models of fatigue-driven exfoliation and demonstrate how crack propagation via thermal stress can lead to their development. The rate and expression of this process will vary with asteroid composition and location, influencing how different bodies evolve and their apparent relative surface ages from space weathering and cratering records. In their study, the authors discuss the potential of thermal weathering on airless bodies. As a case study, they use boulder and fracture morphologies on asteroid Bennu.
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Affiliation(s)
- J L Molaro
- Planetary Science Institute, 1700 E Ft Lowell Rd., STE 106, Tucson, AZ, 85719, USA.
| | - K J Walsh
- Southwest Research Institute, 1050 Walnut St #300, Boulder, CO, 80302, USA
| | - E R Jawin
- Department of Mineral Sciences, National Museum of Natural History, Smithsonian Institution, PO Box 37012, MRC 119, Washington, D.C, 20013, USA
| | - R-L Ballouz
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - C Drouet d'Aubigny
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - S R Schwartz
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - R D Hanna
- Department of Geological Sciences, Jackson School of Geosciences, University of Texas, 2305 Speedway Stop C1160, Austin, TX, 78712, USA
| | - S J Martel
- Department of Earth Sciences, School of Ocean and Earth Science and Technology, University of Hawai'i at Mānoa, POST Building STE 701, 1680 East-West Road, Honolulu, HI, 96822, USA
| | - M Pajola
- INAF-Astronomical Observatory of Padova, Vic. Osservatorio 5, 35122, Padova, Italy
| | - H Campins
- Department of Physics, University of Central Florida, 4111 Libra Drive, Physical Sciences Bldg. 430, Orlando, FL, 32816, USA
| | - A J Ryan
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
| | - W F Bottke
- Southwest Research Institute, 1050 Walnut St #300, Boulder, CO, 80302, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, 1629 E University Blvd, Tucson, AZ, 85721, USA
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8
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Lauretta DS, Hergenrother CW, Chesley SR, Leonard JM, Pelgrift JY, Adam CD, Al Asad M, Antreasian PG, Ballouz RL, Becker KJ, Bennett CA, Bos BJ, Bottke WF, Brozović M, Campins H, Connolly HC, Daly MG, Davis AB, de León J, DellaGiustina DN, Drouet d'Aubigny CY, Dworkin JP, Emery JP, Farnocchia D, Glavin DP, Golish DR, Hartzell CM, Jacobson RA, Jawin ER, Jenniskens P, Kidd JN, Lessac-Chenen EJ, Li JY, Libourel G, Licandro J, Liounis AJ, Maleszewski CK, Manzoni C, May B, McCarthy LK, McMahon JW, Michel P, Molaro JL, Moreau MC, Nelson DS, Owen WM, Rizk B, Roper HL, Rozitis B, Sahr EM, Scheeres DJ, Seabrook JA, Selznick SH, Takahashi Y, Thuillet F, Tricarico P, Vokrouhlický D, Wolner CWV. Episodes of particle ejection from the surface of the active asteroid (101955) Bennu. Science 2020; 366:366/6470/eaay3544. [PMID: 31806784 DOI: 10.1126/science.aay3544] [Citation(s) in RCA: 96] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 10/22/2019] [Indexed: 11/02/2022]
Abstract
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.
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Affiliation(s)
- D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
| | - C W Hergenrother
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
| | - S R Chesley
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | | | | | - C D Adam
- KinetX Aerospace, Simi Valley, CA, USA
| | - M Al Asad
- Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada
| | | | - R-L Ballouz
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - K J Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B J Bos
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - W F Bottke
- Southwest Research Institute, Boulder, CO, USA
| | - M Brozović
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - H Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - H C Connolly
- Department of Geology, Rowan University, Glassboro, NJ, USA.,Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M G Daly
- The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada
| | - A B Davis
- Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - J de León
- Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.,Department of Geosciences, University of Arizona, Tucson, AZ, USA
| | | | - J P Dworkin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J P Emery
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA.,Department of Astronomy and Planetary Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - D Farnocchia
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - D P Glavin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C M Hartzell
- Department of Aerospace Engineering, University of Maryland, College Park, MD, USA
| | - R A Jacobson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - E R Jawin
- Smithsonian Institution National Museum of Natural History, Washington, DC, USA
| | - P Jenniskens
- SETI (Search for Extraterrestrial Intelligence) Institute, Mountain View, CA, USA
| | - J N Kidd
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - J-Y Li
- Planetary Science Institute, Tucson, AZ, USA
| | - G Libourel
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France
| | - J Licandro
- Instituto de Astrofísica de Canarias and Departamento de Astrofísica, Universidad de La Laguna, Tenerife, Spain
| | - A J Liounis
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C K Maleszewski
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C Manzoni
- London Stereoscopic Company, London, UK
| | - B May
- London Stereoscopic Company, London, UK
| | | | - J W McMahon
- Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - P Michel
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France
| | - J L Molaro
- Planetary Science Institute, Tucson, AZ, USA
| | - M C Moreau
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - W M Owen
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H L Roper
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B Rozitis
- School of Physical Sciences, Open University, Milton Keynes, UK
| | - E M Sahr
- KinetX Aerospace, Simi Valley, CA, USA
| | - D J Scheeres
- Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - J A Seabrook
- The Centre for Research in Earth and Space Science, York University, Toronto, ON, Canada
| | - S H Selznick
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Y Takahashi
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - F Thuillet
- Université Côte d'Azur, Observatoire de la Côte d'Azur, CNRS (Centre national de la recherche scientifique), Laboratoire Lagrange, Nice, France
| | - P Tricarico
- Planetary Science Institute, Tucson, AZ, USA
| | - D Vokrouhlický
- Institute of Astronomy, Charles University, Prague, Czech Republic
| | - C W V Wolner
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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9
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Golish DR, Drouet d'Aubigny C, Rizk B, DellaGiustina DN, Smith PH, Becker K, Shultz N, Stone T, Barker MK, Mazarico E, Tatsumi E, Gaskell RW, Harrison L, Merrill C, Fellows C, Williams B, O'Dougherty S, Whiteley M, Hancock J, Clark BE, Hergenrother CW, Lauretta DS. Ground and In-Flight Calibration of the OSIRIS-REx Camera Suite. Space Sci Rev 2020; 216:12. [PMID: 32025061 DOI: 10.1007/s11214-017-0460-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/27/2019] [Indexed: 05/29/2023]
Abstract
The OSIRIS-REx Camera Suite (OCAMS) onboard the OSIRIS-REx spacecraft is used to study the shape and surface of the mission's target, asteroid (101955) Bennu, in support of the selection of a sampling site. We present calibration methods and results for the three OCAMS cameras-MapCam, PolyCam, and SamCam-using data from pre-flight and in-flight calibration campaigns. Pre-flight calibrations established a baseline for a variety of camera properties, including bias and dark behavior, flat fields, stray light, and radiometric calibration. In-flight activities updated these calibrations where possible, allowing us to confidently measure Bennu's surface. Accurate calibration is critical not only for establishing a global understanding of Bennu, but also for enabling analyses of potential sampling locations and for providing scientific context for the returned sample.
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Affiliation(s)
- D R Golish
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | | | - B Rizk
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - D N DellaGiustina
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - P H Smith
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - K Becker
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - N Shultz
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - T Stone
- United States Geological Survey Astrogeology Science Center, Flagstaff, AZ USA
| | - M K Barker
- 3Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E Mazarico
- 3Solar System Exploration Division, NASA Goddard Space Flight Center, Greenbelt, MD USA
| | - E Tatsumi
- 4Department of Earth and Planetary Science, The University of Tokyo, Tokyo, Japan
| | - R W Gaskell
- 5Planetary Science Institute, Tucson, AZ USA
| | - L Harrison
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C Merrill
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - C Fellows
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - B Williams
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - S O'Dougherty
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - M Whiteley
- 6Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - J Hancock
- 6Space Dynamics Laboratory, Utah State University, Logan, UT USA
| | - B E Clark
- 7Department of Physics and Astronomy, Ithaca College, Ithaca, NY USA
| | - C W Hergenrother
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
| | - D S Lauretta
- 1Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ USA
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10
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Lauretta DS, DellaGiustina DN, Bennett CA, Golish DR, Becker KJ, Balram-Knutson SS, Barnouin OS, Becker TL, Bottke WF, Boynton WV, Campins H, Clark BE, Connolly HC, Drouet d'Aubigny CY, Dworkin JP, Emery JP, Enos HL, Hamilton VE, Hergenrother CW, Howell ES, Izawa MRM, Kaplan HH, Nolan MC, Rizk B, Roper HL, Scheeres DJ, Smith PH, Walsh KJ, Wolner CWV. The unexpected surface of asteroid (101955) Bennu. Nature 2019; 568:55-60. [PMID: 30890786 PMCID: PMC6557581 DOI: 10.1038/s41586-019-1033-6] [Citation(s) in RCA: 268] [Impact Index Per Article: 53.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 02/15/2019] [Indexed: 11/09/2022]
Abstract
NASA'S Origins, Spectral Interpretation, Resource Identification and Security-Regolith Explorer (OSIRIS-REx) spacecraft recently arrived at the near-Earth asteroid (101955) Bennu, a primitive body that represents the objects that may have brought prebiotic molecules and volatiles such as water to Earth1. Bennu is a low-albedo B-type asteroid2 that has been linked to organic-rich hydrated carbonaceous chondrites3. Such meteorites are altered by ejection from their parent body and contaminated by atmospheric entry and terrestrial microbes. Therefore, the primary mission objective is to return a sample of Bennu to Earth that is pristine-that is, not affected by these processes4. The OSIRIS-REx spacecraft carries a sophisticated suite of instruments to characterize Bennu's global properties, support the selection of a sampling site and document that site at a sub-centimetre scale5-11. Here we consider early OSIRIS-REx observations of Bennu to understand how the asteroid's properties compare to pre-encounter expectations and to assess the prospects for sample return. The bulk composition of Bennu appears to be hydrated and volatile-rich, as expected. However, in contrast to pre-encounter modelling of Bennu's thermal inertia12 and radar polarization ratios13-which indicated a generally smooth surface covered by centimetre-scale particles-resolved imaging reveals an unexpected surficial diversity. The albedo, texture, particle size and roughness are beyond the spacecraft design specifications. On the basis of our pre-encounter knowledge, we developed a sampling strategy to target 50-metre-diameter patches of loose regolith with grain sizes smaller than two centimetres4. We observe only a small number of apparently hazard-free regions, of the order of 5 to 20 metres in extent, the sampling of which poses a substantial challenge to mission success.
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Affiliation(s)
- D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
| | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C A Bennett
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - K J Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - O S Barnouin
- The Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA
| | - T L Becker
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - W F Bottke
- Southwest Research Institute, Boulder, CO, USA
| | - W V Boynton
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - B E Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - H C Connolly
- Department of Geology, Rowan University, Glassboro, NJ, USA
| | | | - J P Dworkin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J P Emery
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, USA
| | - H L Enos
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | | | - C W Hergenrother
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E S Howell
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M R M Izawa
- Institute for Planetary Materials, Okayama University-Misasa, Misasa, Japan
| | - H H Kaplan
- Southwest Research Institute, Boulder, CO, USA
| | - M C Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - H L Roper
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D J Scheeres
- Smead Department of Aerospace Engineering, University of Colorado, Boulder, CO, USA
| | - P H Smith
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - K J Walsh
- Southwest Research Institute, Boulder, CO, USA
| | - C W V Wolner
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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11
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Hergenrother CW, Maleszewski CK, Nolan MC, Li JY, Drouet d'Aubigny CY, Shelly FC, Howell ES, Kareta TR, Izawa MRM, Barucci MA, Bierhaus EB, Campins H, Chesley SR, Clark BE, Christensen EJ, DellaGiustina DN, Fornasier S, Golish DR, Hartzell CM, Rizk B, Scheeres DJ, Smith PH, Zou XD, Lauretta DS. The operational environment and rotational acceleration of asteroid (101955) Bennu from OSIRIS-REx observations. Nat Commun 2019; 10:1291. [PMID: 30890725 PMCID: PMC6425024 DOI: 10.1038/s41467-019-09213-x] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 02/26/2019] [Indexed: 11/17/2022] Open
Abstract
During its approach to asteroid (101955) Bennu, NASA's Origins, Spectral Interpretation, Resource Identification, and Security-Regolith Explorer (OSIRIS-REx) spacecraft surveyed Bennu's immediate environment, photometric properties, and rotation state. Discovery of a dusty environment, a natural satellite, or unexpected asteroid characteristics would have had consequences for the mission's safety and observation strategy. Here we show that spacecraft observations during this period were highly sensitive to satellites (sub-meter scale) but reveal none, although later navigational images indicate that further investigation is needed. We constrain average dust production in September 2018 from Bennu's surface to an upper limit of 150 g s-1 averaged over 34 min. Bennu's disk-integrated photometric phase function validates measurements from the pre-encounter astronomical campaign. We demonstrate that Bennu's rotation rate is accelerating continuously at 3.63 ± 0.52 × 10-6 degrees day-2, likely due to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect, with evolutionary implications.
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Affiliation(s)
- C W Hergenrother
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA.
| | - C K Maleszewski
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M C Nolan
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J-Y Li
- Planetary Science Institute, Tucson, AZ, USA
| | | | - F C Shelly
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E S Howell
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - T R Kareta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - M R M Izawa
- Institute for Planetary Materials, Okayama University-Misasa, Misasa, Tottori, Japan
| | - M A Barucci
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Univ. Paris Diderot, Sorbonne Paris Cité, Meudon, France
| | | | - H Campins
- Department of Physics, University of Central Florida, Orlando, FL, USA
| | - S R Chesley
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - B E Clark
- Department of Physics and Astronomy, Ithaca College, Ithaca, NY, USA
| | - E J Christensen
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D N DellaGiustina
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S Fornasier
- LESIA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Univ. Paris Diderot, Sorbonne Paris Cité, Meudon, France
| | - D R Golish
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - C M Hartzell
- Department of Aerospace Engineering, University of Maryland, College Park, MD, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D J Scheeres
- Smead Department of Aerospace Engineering, University of Colorado, Boulder, CO, USA
| | - P H Smith
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - X-D Zou
- Planetary Science Institute, Tucson, AZ, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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Ng WR, Golish DR, Xin H, Gehm ME. Direct rapid-prototyping fabrication of computer-generated volume holograms in the millimeter-wave and terahertz regime. Opt Express 2014; 22:3349-3355. [PMID: 24663625 DOI: 10.1364/oe.22.003349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Computer-generated volume holograms (CGVHs) are gradient refractive index (GRIN) devices that consist of a superposition of multiple periodic diffraction gratings. Fabrication of these components for the visible range is difficult due to the small length-scale requirements but is more tenable in the terahertz (THz), as the length scales become more practical (≥ 10-5 m). We successfully utilized polymer-based 3D additive rapid-prototyping technology to fabricate, to our knowledge, the world's first 3D THz CGVH in approximately 50 minutes, using $12 of consumables. This demonstration suggests that this technique could be extended to fabricate THz volumetric optics with arbitrary electromagnetic profiles.
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Golish DR, Vera EM, Kelly KJ, Gong Q, Jansen PA, Hughes JM, Kittle DS, Brady DJ, Gehm ME. Development of a scalable image formation pipeline for multiscale gigapixel photography. Opt Express 2012; 20:22048-22062. [PMID: 23037355 DOI: 10.1364/oe.20.022048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report on the image formation pipeline developed to efficiently form gigapixel-scale imagery generated by the AWARE-2 multiscale camera. The AWARE-2 camera consists of 98 "microcameras" imaging through a shared spherical objective, covering a 120° x 50° field of view with approximately 40 microradian instantaneous field of view (the angular extent of a pixel). The pipeline is scalable, capable of producing imagery ranging in scope from "live" one megapixel views to full resolution gigapixel images. Architectural choices that enable trivially parallelizable algorithms for rapid image formation and on-the-fly microcamera alignment compensation are discussed.
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Affiliation(s)
- D R Golish
- Department of Electrical and Computer Engineering, University of Arizona, Tucson, Arizona, USA.
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Abstract
Spectroscopic chemical classification based on adaptive, feature-specific measurements has been implemented and demonstrated to provide significant performance gain over traditional systems. The measurement scheme and the decision model are discussed. A prototype system with a digital micro-mirror device as the adaptive element has been constructed and validates the theoretical findings and simulation results.
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Affiliation(s)
- D V Dinakarababu
- Department of Electrical and Computer Engineering, University of Arizona, Tucson, AZ 85721, USA
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