1
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Spencer JR, Stern SA, Moore JM, Weaver HA, Singer KN, Olkin CB, Verbiscer AJ, McKinnon WB, Parker JW, Beyer RA, Keane JT, Lauer TR, Porter SB, White OL, Buratti BJ, El-Maarry MR, Lisse CM, Parker AH, Throop HB, Robbins SJ, Umurhan OM, Binzel RP, Britt DT, Buie MW, Cheng AF, Cruikshank DP, Elliott HA, Gladstone GR, Grundy WM, Hill ME, Horanyi M, Jennings DE, Kavelaars JJ, Linscott IR, McComas DJ, McNutt RL, Protopapa S, Reuter DC, Schenk PM, Showalter MR, Young LA, Zangari AM, Abedin AY, Beddingfield CB, Benecchi SD, Bernardoni E, Bierson CJ, Borncamp D, Bray VJ, Chaikin AL, Dhingra RD, Fuentes C, Fuse T, Gay PL, Gwyn SDJ, Hamilton DP, Hofgartner JD, Holman MJ, Howard AD, Howett CJA, Karoji H, Kaufmann DE, Kinczyk M, May BH, Mountain M, Pätzold M, Petit JM, Piquette MR, Reid IN, Reitsema HJ, Runyon KD, Sheppard SS, Stansberry JA, Stryk T, Tanga P, Tholen DJ, Trilling DE, Wasserman LH. The geology and geophysics of Kuiper Belt object (486958) Arrokoth. Science 2020; 367:science.aay3999. [PMID: 32054694 DOI: 10.1126/science.aay3999] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 01/27/2020] [Indexed: 11/02/2022]
Abstract
The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, is composed of primitive objects preserving information about Solar System formation. In January 2019, the New Horizons spacecraft flew past one of these objects, the 36-kilometer-long contact binary (486958) Arrokoth (provisional designation 2014 MU69). Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters in diameter) within a radius of 8000 kilometers. Arrokoth has a lightly cratered, smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism.
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Affiliation(s)
- J R Spencer
- Southwest Research Institute, Boulder, CO 80302, USA.
| | - S A Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J M Moore
- NASA Ames Research Center, Moffett Field, CA 94035-1000, USA
| | - H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - K N Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - C B Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A J Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - W B McKinnon
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA
| | - J Wm Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - R A Beyer
- SETI Institute, Mountain View, CA 94043, USA.,NASA Ames Research Center, Moffett Field, CA 94035-1000, USA
| | - J T Keane
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - T R Lauer
- National Science Foundation's National Optical Infrared Astronomy Research Laboratory, Tucson, AZ 26732, USA
| | - S B Porter
- Southwest Research Institute, Boulder, CO 80302, USA
| | - O L White
- SETI Institute, Mountain View, CA 94043, USA.,NASA Ames Research Center, Moffett Field, CA 94035-1000, USA
| | - B J Buratti
- Jet Propulsion Laboratory, California Institute of Technology Pasadena, CA 91109, USA
| | - M R El-Maarry
- Department of Earth and Planetary Sciences, Birkbeck, University of London, London WC1E 7HX, UK.,University College London, Gower St, Bloomsbury, London WC1E 6BT, UK
| | - C M Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A H Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H B Throop
- Independent Consultant, Washington, D.C., USA
| | - S J Robbins
- Southwest Research Institute, Boulder, CO 80302, USA
| | - O M Umurhan
- NASA Ames Research Center, Moffett Field, CA 94035-1000, USA
| | - R P Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - D T Britt
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - M W Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A F Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D P Cruikshank
- NASA Ames Research Center, Moffett Field, CA 94035-1000, USA
| | - H A Elliott
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - G R Gladstone
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - W M Grundy
- Lowell Observatory, Flagstaff, AZ 86001, USA.,Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - M E Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Horanyi
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - D E Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - J J Kavelaars
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | - I R Linscott
- Independent Consultant, Mountain View, CA 94043, USA
| | - D J McComas
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - R L McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S Protopapa
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D C Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - P M Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | | | - L A Young
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A M Zangari
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A Y Abedin
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | | | - S D Benecchi
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - E Bernardoni
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - C J Bierson
- Earth and Planetary Science Department, University of California, Santa Cruz, CA 95064, USA
| | - D Borncamp
- Decipher Technology Studios, Alexandria, VA 22314, USA
| | - V J Bray
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - A L Chaikin
- Independent Science Writer, Arlington, VT 05250, USA
| | | | - C Fuentes
- Universidad de Chile, Centro de Astrofísica y Tecnologías Afines, Santiago, Chile
| | - T Fuse
- Kashima Space Technology Center, National Institute of Information and Communications Technology, Kashima, Ibaraki 314-8501, Japan
| | - P L Gay
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - S D J Gwyn
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | - D P Hamilton
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - J D Hofgartner
- Jet Propulsion Laboratory, California Institute of Technology Pasadena, CA 91109, USA
| | - M J Holman
- Center for Astrophysics, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA
| | - A D Howard
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA
| | - C J A Howett
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H Karoji
- National Institutes of Natural Sciences, Tokyo, Japan
| | - D E Kaufmann
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M Kinczyk
- Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - B H May
- Independent Collaborator, Windlesham GU20 6YW, UK
| | - M Mountain
- Association of Universities for Research in Astronomy, Washington, DC 20004, USA
| | - M Pätzold
- Rheinisches Institut für Umweltforschung an der Universität zu Köln, Cologne 50931, Germany
| | - J M Petit
- Institut Univers, Temps-fréquence, Interfaces, Nanostructures, Atmosphère et environnement, Molécules, Unité Mixte de Recherche, Centre National de la Recherche Scientifique, Universite Bourgogne Franche Comte, F-25000 Besancon, France
| | - M R Piquette
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - I N Reid
- Space Telescope Science Institute, Baltimore, MD 21218, USA
| | | | - K D Runyon
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S S Sheppard
- Department of Terrestrial Magnetism, Carnegie Institution for Science, Washington, DC 20015, USA
| | - J A Stansberry
- Space Telescope Science Institute, Baltimore, MD 21218, USA
| | - T Stryk
- Roane State Community College, Oak Ridge, TN 37830, USA
| | - P Tanga
- Université Côte d'Azur, Observatoire de la Côte d'Azur, Laboratoire Lagrange/ Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7293, 06304 Nice Cedex 4, France
| | - D J Tholen
- Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA
| | - D E Trilling
- Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ, 86011, USA
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2
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Grundy WM, Bird MK, Britt DT, Cook JC, Cruikshank DP, Howett CJA, Krijt S, Linscott IR, Olkin CB, Parker AH, Protopapa S, Ruaud M, Umurhan OM, Young LA, Dalle Ore CM, Kavelaars JJ, Keane JT, Pendleton YJ, Porter SB, Scipioni F, Spencer JR, Stern SA, Verbiscer AJ, Weaver HA, Binzel RP, Buie MW, Buratti BJ, Cheng A, Earle AM, Elliott HA, Gabasova L, Gladstone GR, Hill ME, Horanyi M, Jennings DE, Lunsford AW, McComas DJ, McKinnon WB, McNutt RL, Moore JM, Parker JW, Quirico E, Reuter DC, Schenk PM, Schmitt B, Showalter MR, Singer KN, Weigle GE, Zangari AM. Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth. Science 2020; 367:science.aay3705. [PMID: 32054693 DOI: 10.1126/science.aay3705] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 01/22/2020] [Indexed: 11/02/2022]
Abstract
The outer Solar System object (486958) Arrokoth (provisional designation 2014 MU69) has been largely undisturbed since its formation. We studied its surface composition using data collected by the New Horizons spacecraft. Methanol ice is present along with organic material, which may have formed through irradiation of simple molecules. Water ice was not detected. This composition indicates hydrogenation of carbon monoxide-rich ice and/or energetic processing of methane condensed on water ice grains in the cold, outer edge of the early Solar System. There are only small regional variations in color and spectra across the surface, which suggests that Arrokoth formed from a homogeneous or well-mixed reservoir of solids. Microwave thermal emission from the winter night side is consistent with a mean brightness temperature of 29 ± 5 kelvin.
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Affiliation(s)
- W M Grundy
- Lowell Observatory, Flagstaff, AZ 86001, USA. .,Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - M K Bird
- Argelander-Institut für Astronomie, University of Bonn, D-53121 Bonn, Germany.,Rheinisches Institut für Umweltforschung, Universität zu Köln, 50931 Cologne, Germany
| | - D T Britt
- University of Central Florida, Orlando, FL 32816, USA
| | - J C Cook
- Pinhead Institute, Telluride, CO 81435, USA
| | | | - C J A Howett
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S Krijt
- Steward Observatory, University of Arizona, Tucson, AZ 85719, USA
| | | | - C B Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A H Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S Protopapa
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M Ruaud
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - O M Umurhan
- NASA Ames Research Center, Moffett Field, CA 94035, USA.,Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - L A Young
- Southwest Research Institute, Boulder, CO 80302, USA
| | - C M Dalle Ore
- NASA Ames Research Center, Moffett Field, CA 94035, USA.,Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - J J Kavelaars
- National Research Council, Victoria, BC V9E 2E7, Canada.,Department of Physics and Astronomy, University of Victoria, Victoria, BC V8W 2Y2, Canada
| | - J T Keane
- California Institute of Technology, Pasadena, CA 91125, USA
| | - Y J Pendleton
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - S B Porter
- Southwest Research Institute, Boulder, CO 80302, USA
| | - F Scipioni
- NASA Ames Research Center, Moffett Field, CA 94035, USA.,Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - J R Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S A Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A J Verbiscer
- University of Virginia, Charlottesville, VA 22904, USA
| | - H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - R P Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - M W Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B J Buratti
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - A Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A M Earle
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - H A Elliott
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - L Gabasova
- Institut de Planétologie et d'Astrophysique de Grenoble, Centre National de la Recherche Scientifique, Université Grenoble Alpes, Grenoble, France
| | - G R Gladstone
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - M E Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Horanyi
- University of Colorado, Boulder, CO 80309, USA
| | - D E Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - A W Lunsford
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D J McComas
- Princeton University, Princeton, NJ 08544, USA
| | | | - R L McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J M Moore
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - J W Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - E Quirico
- Institut de Planétologie et d'Astrophysique de Grenoble, Centre National de la Recherche Scientifique, Université Grenoble Alpes, Grenoble, France
| | - D C Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - P M Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | - B Schmitt
- Institut de Planétologie et d'Astrophysique de Grenoble, Centre National de la Recherche Scientifique, Université Grenoble Alpes, Grenoble, France
| | - M R Showalter
- Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - K N Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - G E Weigle
- Big Head Endian LLC, Leawood, KS 67019, USA
| | - A M Zangari
- Southwest Research Institute, Boulder, CO 80302, USA
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3
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McKinnon WB, Richardson DC, Marohnic JC, Keane JT, Grundy WM, Hamilton DP, Nesvorný D, Umurhan OM, Lauer TR, Singer KN, Stern SA, Weaver HA, Spencer JR, Buie MW, Moore JM, Kavelaars JJ, Lisse CM, Mao X, Parker AH, Porter SB, Showalter MR, Olkin CB, Cruikshank DP, Elliott HA, Gladstone GR, Parker JW, Verbiscer AJ, Young LA. The solar nebula origin of (486958) Arrokoth, a primordial contact binary in the Kuiper Belt. Science 2020; 367:science.aay6620. [PMID: 32054695 DOI: 10.1126/science.aay6620] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 01/27/2020] [Indexed: 11/02/2022]
Abstract
The New Horizons spacecraft's encounter with the cold classical Kuiper Belt object (486958) Arrokoth (provisional designation 2014 MU69) revealed a contact-binary planetesimal. We investigated how Arrokoth formed and found that it is the product of a gentle, low-speed merger in the early Solar System. Its two lenticular lobes suggest low-velocity accumulation of numerous smaller planetesimals within a gravitationally collapsing cloud of solid particles. The geometric alignment of the lobes indicates that they were a co-orbiting binary that experienced angular momentum loss and subsequent merger, possibly because of dynamical friction and collisions within the cloud or later gas drag. Arrokoth's contact-binary shape was preserved by the benign dynamical and collisional environment of the cold classical Kuiper Belt and therefore informs the accretion processes that operated in the early Solar System.
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Affiliation(s)
- W B McKinnon
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA.
| | - D C Richardson
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - J C Marohnic
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - J T Keane
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - W M Grundy
- Lowell Observatory, Flagstaff, AZ 86001, USA.,Department of Astronomy and Planetary Science, Northern Arizona University, Flagstaff, AZ 86011, USA
| | - D P Hamilton
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - D Nesvorný
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - O M Umurhan
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - T R Lauer
- National Optical-Infrared Astronomy Research Laboratory, National Science Foundation, Tucson, AZ 85726, USA
| | - K N Singer
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - S A Stern
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J R Spencer
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | - M W Buie
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - J M Moore
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - J J Kavelaars
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | - C M Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - X Mao
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - A H Parker
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - S B Porter
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | | | - C B Olkin
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - D P Cruikshank
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - H A Elliott
- Division of Space Science and Engineering, Southwest Research Institute, San Antonio, TX 78238, USA.,Department of Physics and Astronomy, University of Texas, San Antonio, TX 78249, USA
| | - G R Gladstone
- Division of Space Science and Engineering, Southwest Research Institute, San Antonio, TX 78238, USA
| | - J Wm Parker
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
| | - A J Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - L A Young
- Division of Space Science and Engineering, Southwest Research Institute, Boulder, CO 80302, USA
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Kollmann P, Hill ME, Allen RC, McNutt RL, Brown LE, Barnes NP, Delamere P, Clark G, Andrews GB, Salazar N, Westlake J, Romeo G, Vandegriff J, Kusterer M, Smith D, Nelson K, Jaskulek S, Decker RB, Cheng AF, Krimigis SM, Lisse CM, Mitchell DG, Weaver HA, Elliott HA, Fattig E, Gladstone GR, Valek PW, Weidner S, Kammer J, Bagenal F, Horanyi M, Kaufmann D, Harch A, Olkin CB, Piquette MR, Spencer JR, Young LA, Ennico K, Summers ME, Stern SA. Pluto's Interaction With Energetic Heliospheric Ions. J Geophys Res Space Phys 2019; 124:7413-7424. [PMID: 35860291 PMCID: PMC9285724 DOI: 10.1029/2019ja026830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/08/2019] [Accepted: 07/10/2019] [Indexed: 06/15/2023]
Abstract
Pluto energies of a few kiloelectron volts and suprathermal ions with tens of kiloelectron volts and above. We measure this population using the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument on board the New Horizons spacecraft that flew by Pluto in 2015. Even though the measured ions have gyroradii larger than the size of Pluto and the cross section of its magnetosphere, we find that the boundary of the magnetosphere is depleting the energetic ion intensities by about an order of magnitude close to Pluto. The intensity is increasing exponentially with distance to Pluto and reaches nominal levels of the interplanetary medium at about 190R P distance. Inside the wake of Pluto, we observe oscillations of the ion intensities with a periodicity of about 0.2 hr. We show that these can be quantitatively explained by the electric field of an ultralow-frequency wave and discuss possible physical drivers for such a field. We find no evidence for the presence of plutogenic ions in the considered energy range.
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5
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Cruikshank DP, Materese CK, Pendleton YJ, Boston PJ, Grundy WM, Schmitt B, Lisse CM, Runyon KD, Keane JT, Beyer RA, Summers ME, Scipioni F, Stern SA, Dalle Ore CM, Olkin CB, Young LA, Ennico K, Weaver HA, Bray VJ. Prebiotic Chemistry of Pluto. Astrobiology 2019; 19:831-848. [PMID: 30907634 DOI: 10.1089/ast.2018.1927] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We present the case for the presence of complex organic molecules, such as amino acids and nucleobases, formed by abiotic processes on the surface and in near-subsurface regions of Pluto. Pluto's surface is tinted with a range of non-ice substances with colors ranging from light yellow to red to dark brown; the colors match those of laboratory organic residues called tholins. Tholins are broadly characterized as complex, macromolecular organic solids consisting of a network of aromatic structures connected by aliphatic bridging units (e.g., Imanaka et al., 2004; Materese et al., 2014, 2015). The synthesis of tholins in planetary atmospheres and in surface ices has been explored in numerous laboratory experiments, and both gas- and solid-phase varieties are found on Pluto. A third variety of tholins, exposed at a site of tectonic surface fracturing called Virgil Fossae, appears to have come from a reservoir in the subsurface. Eruptions of tholin-laden liquid H2O from a subsurface aqueous repository appear to have covered portions of Virgil Fossae and its surroundings with a uniquely colored deposit (D.P. Cruikshank, personal communication) that is geographically correlated with an exposure of H2O ice that includes spectroscopically detected NH3 (C.M. Dalle Ore, personal communication). The subsurface organic material could have been derived from presolar or solar nebula processes, or might have formed in situ. Photolysis and radiolysis of a mixture of ices relevant to Pluto's surface composition (N2, CH4, CO) have produced strongly colored, complex organics with a significant aromatic content having a high degree of nitrogen substitution similar to the aromatic heterocycles pyrimidine and purine (Materese et al., 2014, 2015; Cruikshank et al., 2016). Experiments with pyrimidines and purines frozen in H2O-NH3 ice resulted in the formation of numerous nucleobases, including the biologically relevant guanine, cytosine, adenine, uracil, and thymine (Materese et al., 2017). The red material associated with the H2O ice may contain nucleobases resulting from energetic processing on Pluto's surface or in the interior. Some other Kuiper Belt objects also exhibit red colors similar to those found on Pluto and may therefore carry similar inventories of complex organic materials. The widespread and ubiquitous nature of similarly complex organic materials observed in a variety of astronomical settings drives the need for additional laboratory and modeling efforts to explain the origin and evolution of organic molecules. Pluto observations reveal complex organics on a small body that remains close to its place of origin in the outermost regions of the Solar System.
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Affiliation(s)
- D P Cruikshank
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - C K Materese
- 2Goddard Space Flight Center, Greenbelt, Maryland, USA
| | - Y J Pendleton
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - P J Boston
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - W M Grundy
- 3Lowell Observatory, Flagstaff, Arizona, USA
| | - B Schmitt
- 4Université Grenoble Alpes, CNRS, IPAG, Grenoble, France
| | - C M Lisse
- 5Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, USA
| | - K D Runyon
- 5Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, USA
| | - J T Keane
- 6California Institute of Technology, Pasadena, California, USA
| | - R A Beyer
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - M E Summers
- 7Department of Physics and Astronomy, George Mason University, Fairfax, Virginia, USA
| | - F Scipioni
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - S A Stern
- 8Southwest Research Institute, Boulder, Colorado, USA
| | - C M Dalle Ore
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - C B Olkin
- 8Southwest Research Institute, Boulder, Colorado, USA
| | - L A Young
- 8Southwest Research Institute, Boulder, Colorado, USA
| | - K Ennico
- 1NASA Ames Research Center, Moffett Field, California, USA
| | - H A Weaver
- 5Applied Physics Laboratory, Johns Hopkins University, Laurel, Maryland, USA
| | - V J Bray
- 9Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona, USA
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6
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Stern SA, Weaver HA, Spencer JR, Olkin CB, Gladstone GR, Grundy WM, Moore JM, Cruikshank DP, Elliott HA, McKinnon WB, Parker JW, Verbiscer AJ, Young LA, Aguilar DA, Albers JM, Andert T, Andrews JP, Bagenal F, Banks ME, Bauer BA, Bauman JA, Bechtold KE, Beddingfield CB, Behrooz N, Beisser KB, Benecchi SD, Bernardoni E, Beyer RA, Bhaskaran S, Bierson CJ, Binzel RP, Birath EM, Bird MK, Boone DR, Bowman AF, Bray VJ, Britt DT, Brown LE, Buckley MR, Buie MW, Buratti BJ, Burke LM, Bushman SS, Carcich B, Chaikin AL, Chavez CL, Cheng AF, Colwell EJ, Conard SJ, Conner MP, Conrad CA, Cook JC, Cooper SB, Custodio OS, Dalle Ore CM, Deboy CC, Dharmavaram P, Dhingra RD, Dunn GF, Earle AM, Egan AF, Eisig J, El-Maarry MR, Engelbrecht C, Enke BL, Ercol CJ, Fattig ED, Ferrell CL, Finley TJ, Firer J, Fischetti J, Folkner WM, Fosbury MN, Fountain GH, Freeze JM, Gabasova L, Glaze LS, Green JL, Griffith GA, Guo Y, Hahn M, Hals DW, Hamilton DP, Hamilton SA, Hanley JJ, Harch A, Harmon KA, Hart HM, Hayes J, Hersman CB, Hill ME, Hill TA, Hofgartner JD, Holdridge ME, Horányi M, Hosadurga A, Howard AD, Howett CJA, Jaskulek SE, Jennings DE, Jensen JR, Jones MR, Kang HK, Katz DJ, Kaufmann DE, Kavelaars JJ, Keane JT, Keleher GP, Kinczyk M, Kochte MC, Kollmann P, Krimigis SM, Kruizinga GL, Kusnierkiewicz DY, Lahr MS, Lauer TR, Lawrence GB, Lee JE, Lessac-Chenen EJ, Linscott IR, Lisse CM, Lunsford AW, Mages DM, Mallder VA, Martin NP, May BH, McComas DJ, McNutt RL, Mehoke DS, Mehoke TS, Nelson DS, Nguyen HD, Núñez JI, Ocampo AC, Owen WM, Oxton GK, Parker AH, Pätzold M, Pelgrift JY, Pelletier FJ, Pineau JP, Piquette MR, Porter SB, Protopapa S, Quirico E, Redfern JA, Regiec AL, Reitsema HJ, Reuter DC, Richardson DC, Riedel JE, Ritterbush MA, Robbins SJ, Rodgers DJ, Rogers GD, Rose DM, Rosendall PE, Runyon KD, Ryschkewitsch MG, Saina MM, Salinas MJ, Schenk PM, Scherrer JR, Schlei WR, Schmitt B, Schultz DJ, Schurr DC, Scipioni F, Sepan RL, Shelton RG, Showalter MR, Simon M, Singer KN, Stahlheber EW, Stanbridge DR, Stansberry JA, Steffl AJ, Strobel DF, Stothoff MM, Stryk T, Stuart JR, Summers ME, Tapley MB, Taylor A, Taylor HW, Tedford RM, Throop HB, Turner LS, Umurhan OM, Van Eck J, Velez D, Versteeg MH, Vincent MA, Webbert RW, Weidner SE, Weigle GE, Wendel JR, White OL, Whittenburg KE, Williams BG, Williams KE, Williams SP, Winters HL, Zangari AM, Zurbuchen TH. Initial results from the New Horizons exploration of 2014 MU 69, a small Kuiper Belt object. Science 2019; 364:364/6441/eaaw9771. [PMID: 31097641 DOI: 10.1126/science.aaw9771] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 04/16/2019] [Indexed: 11/02/2022]
Abstract
The Kuiper Belt is a distant region of the outer Solar System. On 1 January 2019, the New Horizons spacecraft flew close to (486958) 2014 MU69, a cold classical Kuiper Belt object approximately 30 kilometers in diameter. Such objects have never been substantially heated by the Sun and are therefore well preserved since their formation. We describe initial results from these encounter observations. MU69 is a bilobed contact binary with a flattened shape, discrete geological units, and noticeable albedo heterogeneity. However, there is little surface color or compositional heterogeneity. No evidence for satellites, rings or other dust structures, a gas coma, or solar wind interactions was detected. MU69's origin appears consistent with pebble cloud collapse followed by a low-velocity merger of its two lobes.
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Affiliation(s)
- S A Stern
- Southwest Research Institute, Boulder, CO 80302, USA.
| | - H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J R Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - C B Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - G R Gladstone
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - W M Grundy
- Lowell Observatory, Flagstaff, AZ 86001, USA
| | - J M Moore
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - D P Cruikshank
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - H A Elliott
- Southwest Research Institute, San Antonio, TX 78238, USA.,Department of Physics and Astronomy, University of Texas, San Antonio, TX 78249, USA
| | - W B McKinnon
- Department of Earth and Planetary Sciences and McDonnell Center for the Space Sciences, Washington University, St. Louis, MO 63130, USA
| | - J Wm Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A J Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - L A Young
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D A Aguilar
- Independent consultant, Carbondale, CO 81623, USA
| | - J M Albers
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T Andert
- Universität der Bundeswehr München, Neubiberg 85577, Germany
| | - J P Andrews
- Southwest Research Institute, Boulder, CO 80302, USA
| | - F Bagenal
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - M E Banks
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - B A Bauer
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - K E Bechtold
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C B Beddingfield
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - N Behrooz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - K B Beisser
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S D Benecchi
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - E Bernardoni
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - R A Beyer
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - S Bhaskaran
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - C J Bierson
- Earth and Planetary Science Department, University of California, Santa Cruz, CA 95064, USA
| | - R P Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - E M Birath
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M K Bird
- Argelander-Institut für Astronomie, University of Bonn, Bonn D-53121, Germany.,Rheinisches Institut für Umweltforschung, Universität zu Köln, Cologne 50931, Germany
| | - D R Boone
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - A F Bowman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - V J Bray
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - D T Britt
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - L E Brown
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M R Buckley
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M W Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B J Buratti
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - L M Burke
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S S Bushman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - B Carcich
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.,Cornell University, Ithaca, NY 14853, USA
| | - A L Chaikin
- Independent science writer, Arlington, VT 05250, USA
| | - C L Chavez
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - A F Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - E J Colwell
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S J Conard
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M P Conner
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C A Conrad
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J C Cook
- Pinhead Institute, Telluride, CO 81435, USA
| | - S B Cooper
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - O S Custodio
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C M Dalle Ore
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - C C Deboy
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - P Dharmavaram
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - G F Dunn
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - A M Earle
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - A F Egan
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J Eisig
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M R El-Maarry
- Department of Earth and Planetary Sciences, Birkbeck, University of London, London WC1E 7HX, UK
| | - C Engelbrecht
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - B L Enke
- Southwest Research Institute, Boulder, CO 80302, USA
| | - C J Ercol
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - E D Fattig
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - C L Ferrell
- Southwest Research Institute, Boulder, CO 80302, USA
| | - T J Finley
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J Firer
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - W M Folkner
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M N Fosbury
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - G H Fountain
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J M Freeze
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - L Gabasova
- University Grenoble Alpes, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, 38000 Grenoble, France
| | - L S Glaze
- NASA Headquarters, Washington, DC 20546, USA
| | - J L Green
- NASA Headquarters, Washington, DC 20546, USA
| | - G A Griffith
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - Y Guo
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Hahn
- Rheinisches Institut für Umweltforschung, Universität zu Köln, Cologne 50931, Germany
| | - D W Hals
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D P Hamilton
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - S A Hamilton
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J J Hanley
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - A Harch
- Cornell University, Ithaca, NY 14853, USA
| | - K A Harmon
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - H M Hart
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J Hayes
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C B Hersman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M E Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T A Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J D Hofgartner
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M E Holdridge
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Horányi
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - A Hosadurga
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A D Howard
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA
| | - C J A Howett
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S E Jaskulek
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D E Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - J R Jensen
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M R Jones
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - H K Kang
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D J Katz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D E Kaufmann
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J J Kavelaars
- National Research Council of Canada, Victoria, BC V9E 2E7, Canada
| | - J T Keane
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - G P Keleher
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Kinczyk
- Marine, Earth, and Atmospheric Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - M C Kochte
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - P Kollmann
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S M Krimigis
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - G L Kruizinga
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - D Y Kusnierkiewicz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M S Lahr
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T R Lauer
- National Optical Astronomy Observatory, Tucson, AZ 26732, USA
| | - G B Lawrence
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J E Lee
- NASA Marshall Space Flight Center, Huntsville, AL 35812, USA
| | | | - I R Linscott
- Independent consultant, Mountain View, CA 94043, USA
| | - C M Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A W Lunsford
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D M Mages
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - V A Mallder
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - N P Martin
- Independent consultant, Crested Butte, CO 81224, USA
| | - B H May
- Independent collaborator, Windlesham GU20 6YW, UK
| | - D J McComas
- Southwest Research Institute, San Antonio, TX 78238, USA.,Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - R L McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D S Mehoke
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T S Mehoke
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - H D Nguyen
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J I Núñez
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A C Ocampo
- NASA Headquarters, Washington, DC 20546, USA
| | - W M Owen
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - G K Oxton
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A H Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M Pätzold
- Rheinisches Institut für Umweltforschung, Universität zu Köln, Cologne 50931, Germany
| | | | | | - J P Pineau
- Stellar Solutions, Palo Alto, CA 94306, USA
| | - M R Piquette
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - S B Porter
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S Protopapa
- Southwest Research Institute, Boulder, CO 80302, USA
| | - E Quirico
- University Grenoble Alpes, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, 38000 Grenoble, France
| | - J A Redfern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A L Regiec
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - D C Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D C Richardson
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - J E Riedel
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M A Ritterbush
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - S J Robbins
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D J Rodgers
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - G D Rogers
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D M Rose
- Southwest Research Institute, Boulder, CO 80302, USA
| | - P E Rosendall
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - K D Runyon
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M G Ryschkewitsch
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M M Saina
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - P M Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | - J R Scherrer
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - W R Schlei
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - B Schmitt
- University Grenoble Alpes, Centre National de la Recherche Scientifique, Institut de Planétologie et d'Astrophysique de Grenoble, 38000 Grenoble, France
| | - D J Schultz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D C Schurr
- NASA Headquarters, Washington, DC 20546, USA
| | - F Scipioni
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - R L Sepan
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - R G Shelton
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - M Simon
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - K N Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - E W Stahlheber
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - J A Stansberry
- Space Telescope Science Institute, Baltimore, MD 21218, USA
| | - A J Steffl
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D F Strobel
- Johns Hopkins University, Baltimore, MD 21218, USA
| | - M M Stothoff
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - T Stryk
- Roane State Community College, Oak Ridge, TN 37830, USA
| | - J R Stuart
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M E Summers
- George Mason University, Fairfax, VA 22030, USA
| | - M B Tapley
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - A Taylor
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - H W Taylor
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - R M Tedford
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H B Throop
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - L S Turner
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - O M Umurhan
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - J Van Eck
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D Velez
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M H Versteeg
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - M A Vincent
- Southwest Research Institute, Boulder, CO 80302, USA
| | - R W Webbert
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S E Weidner
- Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544, USA
| | - G E Weigle
- Independent consultant, Burden, KS 67019, USA
| | - J R Wendel
- NASA Headquarters, Washington, DC 20546, USA
| | - O L White
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA.,SETI Institute, Mountain View, CA 94043, USA
| | - K E Whittenburg
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | | | - S P Williams
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - H L Winters
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A M Zangari
- Southwest Research Institute, Boulder, CO 80302, USA
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7
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Dalle Ore CM, Cruikshank DP, Protopapa S, Scipioni F, McKinnon WB, Cook JC, Grundy WM, Schmitt B, Stern SA, Moore JM, Verbiscer A, Parker AH, Singer KN, Umurhan OM, Weaver HA, Olkin CB, Young LA, Ennico K. Detection of ammonia on Pluto's surface in a region of geologically recent tectonism. Sci Adv 2019; 5:eaav5731. [PMID: 31608308 PMCID: PMC6771079 DOI: 10.1126/sciadv.aav5731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 04/25/2019] [Indexed: 06/10/2023]
Abstract
We report the detection of ammonia (NH3) on Pluto's surface in spectral images obtained with the New Horizons spacecraft that show absorption bands at 1.65 and 2.2 μm. The ammonia signature is spatially coincident with a region of past extensional tectonic activity (Virgil Fossae) where the presence of H2O ice is prominent. Ammonia in liquid water profoundly depresses the freezing point of the mixture. Ammoniated ices are believed to be geologically short lived when irradiated with ultraviolet photons or charged particles. Thus, the presence of NH3 on a planetary surface is indicative of a relatively recent deposition or possibly through exposure by some geological process. In the present case, the areal distribution is more suggestive of cryovolcanic emplacement, however, adding to the evidence for ongoing geological activity on Pluto and the possible presence of liquid water at depth today.
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Affiliation(s)
- C. M. Dalle Ore
- SETI Institute, Mountain View CA, USA
- NASA Ames Research Center, Moffett Field CA, USA
| | | | | | - F. Scipioni
- SETI Institute, Mountain View CA, USA
- NASA Ames Research Center, Moffett Field CA, USA
| | - W. B. McKinnon
- Department of Earth and Planetary Sciences and the McDonnell Center for the Space Sciences, Washington University, St. Louis, MO, USA
| | | | | | - B. Schmitt
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - S. A. Stern
- Southwest Research Institute, Boulder CO, USA
| | - J. M. Moore
- NASA Ames Research Center, Moffett Field CA, USA
| | - A. Verbiscer
- Johns Hopkins University Applied Physics Laboratory, Laurel MD, USA
| | | | | | - O. M. Umurhan
- SETI Institute, Mountain View CA, USA
- NASA Ames Research Center, Moffett Field CA, USA
| | - H. A. Weaver
- University of Virginia, Charlottesville, VA, USA
| | - C. B. Olkin
- Southwest Research Institute, Boulder CO, USA
| | - L. A. Young
- Southwest Research Institute, Boulder CO, USA
| | - K. Ennico
- NASA Ames Research Center, Moffett Field CA, USA
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8
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Singer KN, McKinnon WB, Gladman B, Greenstreet S, Bierhaus EB, Stern SA, Parker AH, Robbins SJ, Schenk PM, Grundy WM, Bray VJ, Beyer RA, Binzel RP, Weaver HA, Young LA, Spencer JR, Kavelaars JJ, Moore JM, Zangari AM, Olkin CB, Lauer TR, Lisse CM, Ennico K. Impact craters on Pluto and Charon indicate a deficit of small Kuiper belt objects. Science 2019; 363:955-959. [PMID: 30819958 DOI: 10.1126/science.aap8628] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 02/05/2019] [Indexed: 11/02/2022]
Abstract
The flyby of Pluto and Charon by the New Horizons spacecraft provided high-resolution images of cratered surfaces embedded in the Kuiper belt, an extensive region of bodies orbiting beyond Neptune. Impact craters on Pluto and Charon were formed by collisions with other Kuiper belt objects (KBOs) with diameters from ~40 kilometers to ~300 meters, smaller than most KBOs observed directly by telescopes. We find a relative paucity of small craters ≲13 kilometers in diameter, which cannot be explained solely by geological resurfacing. This implies a deficit of small KBOs (≲1 to 2 kilometers in diameter). Some surfaces on Pluto and Charon are likely ≳4 billion years old, thus their crater records provide information on the size-frequency distribution of KBOs in the early Solar System.
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9
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Zirnstein EJ, McComas DJ, Kumar R, Elliott HA, Szalay JR, Olkin CB, Spencer J, Stern SA, Young LA. In Situ Observations of Preferential Pickup Ion Heating at an Interplanetary Shock. Phys Rev Lett 2018; 121:075102. [PMID: 30169088 DOI: 10.1103/physrevlett.121.075102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Indexed: 06/08/2023]
Abstract
Nonthermal pickup ions (PUIs) are created in the solar wind (SW) by charge-exchange between SW ions (SWIs) and slow interstellar neutral atoms. It has long been theorized, but not directly observed that PUIs should be preferentially heated at quasiperpendicular shocks compared to thermal SWIs. We present in situ observations of interstellar hydrogen (H^{+}) PUIs at an interplanetary shock by the New Horizons' Solar Wind Around Pluto (SWAP) instrument at ∼34 au from the Sun. At this shock, H^{+} PUIs are only a few percent of the total proton density but contain most of the internal particle pressure. A gradual reduction in SW flow speed and simultaneous heating of H^{+} SWIs is observed ahead of the shock, suggesting an upstream energetic particle pressure gradient. H^{+} SWIs lose ∼85% of their energy flux across the shock and H^{+} PUIs are preferentially heated. Moreover, a PUI tail is observed downstream of the shock, such that the energy flux of all H^{+} PUIs is approximately six times that of H^{+} SWIs. We find that H^{+} PUIs, including their suprathermal tail, contain almost half of the total downstream energy flux in the shock frame.
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Affiliation(s)
- E J Zirnstein
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
| | - D J McComas
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - R Kumar
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
| | - H A Elliott
- Southwest Research Institute, San Antonio, Texas 78238, USA
| | - J R Szalay
- Department of Astrophysical Sciences, Princeton University, Princeton, New Jersey 08544, USA
| | - C B Olkin
- Southwest Research Institute, Boulder, Colorado 80302, USA
| | - J Spencer
- Southwest Research Institute, Boulder, Colorado 80302, USA
| | - S A Stern
- Southwest Research Institute, Boulder, Colorado 80302, USA
| | - L A Young
- Southwest Research Institute, Boulder, Colorado 80302, USA
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10
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Hamilton DP, Stern SA, Moore JM, Young LA. The rapid formation of Sputnik Planitia early in Pluto's history. Nature 2016; 540:97-99. [PMID: 27905411 DOI: 10.1038/nature20586] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Accepted: 10/28/2016] [Indexed: 11/09/2022]
Abstract
Pluto's Sputnik Planitia is a bright, roughly circular feature that resembles a polar ice cap. It is approximately 1,000 kilometres across and is centred on a latitude of 25 degrees north and a longitude of 175 degrees, almost directly opposite the side of Pluto that always faces Charon as a result of tidal locking. One explanation for its location includes the formation of a basin in a giant impact, with subsequent upwelling of a dense interior ocean. Once the basin was established, ice would naturally have accumulated there. Then, provided that the basin was a positive gravity anomaly (with or without the ocean), true polar wander could have moved the feature towards the Pluto-Charon tidal axis, on the far side of Pluto from Charon. Here we report modelling that shows that ice quickly accumulates on Pluto near latitudes of 30 degrees north and south, even in the absence of a basin, because, averaged over its orbital period, those are Pluto's coldest regions. Within a million years of Charon's formation, ice deposits on Pluto concentrate into a single cap centred near a latitude of 30 degrees, owing to the runaway albedo effect. This accumulation of ice causes a positive gravity signature that locks, as Pluto's rotation slows, to a longitude directly opposite Charon. Once locked, Charon raises a permanent tidal bulge on Pluto, which greatly enhances the gravity signature of the ice cap. Meanwhile, the weight of the ice in Sputnik Planitia causes the crust under it to slump, creating its own basin (as has happened on Earth in Greenland). Even if the feature is now a modest negative gravity anomaly, it remains locked in place because of the permanent tidal bulge raised by Charon. Any movement of the feature away from 30 degrees latitude is countered by the preferential recondensation of ices near the coldest extremities of the cap. Therefore, our modelling suggests that Sputnik Planitia formed shortly after Charon did and has been stable, albeit gradually losing volume, over the age of the Solar System.
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Affiliation(s)
| | | | - J M Moore
- NASA Ames, Mountain View, California, USA
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11
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Nimmo F, Hamilton DP, McKinnon WB, Schenk PM, Binzel RP, Bierson CJ, Beyer RA, Moore JM, Stern SA, Weaver HA, Olkin CB, Young LA, Smith KE. Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto. Nature 2016; 540:94-96. [DOI: 10.1038/nature20148] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 10/03/2016] [Indexed: 11/09/2022]
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12
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McKinnon WB, Nimmo F, Wong T, Schenk PM, White OL, Roberts JH, Moore JM, Spencer JR, Howard AD, Umurhan OM, Stern SA, Weaver HA, Olkin CB, Young LA, Smith KE. Erratum: Corrigendum: Convection in a volatile nitrogen-ice-rich layer drives Pluto’s geological vigour. Nature 2016; 537:122. [DOI: 10.1038/nature18937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Weaver HA, Buie MW, Buratti BJ, Grundy WM, Lauer TR, Olkin CB, Parker AH, Porter SB, Showalter MR, Spencer JR, Stern SA, Verbiscer AJ, McKinnon WB, Moore JM, Robbins SJ, Schenk P, Singer KN, Barnouin OS, Cheng AF, Ernst CM, Lisse CM, Jennings DE, Lunsford AW, Reuter DC, Hamilton DP, Kaufmann DE, Ennico K, Young LA, Beyer RA, Binzel RP, Bray VJ, Chaikin AL, Cook JC, Cruikshank DP, Dalle Ore CM, Earle AM, Gladstone GR, Howett CJA, Linscott IR, Nimmo F, Parker JW, Philippe S, Protopapa S, Reitsema HJ, Schmitt B, Stryk T, Summers ME, Tsang CCC, Throop HHB, White OL, Zangari AM. The small satellites of Pluto as observed by New Horizons. Science 2016; 351:aae0030. [PMID: 26989256 DOI: 10.1126/science.aae0030] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The New Horizons mission has provided resolved measurements of Pluto's moons Styx, Nix, Kerberos, and Hydra. All four are small, with equivalent spherical diameters of ~40 kilometers for Nix and Hydra and ~10 kilometers for Styx and Kerberos. They are also highly elongated, with maximum to minimum axis ratios of ~2. All four moons have high albedos (~50 to 90%) suggestive of a water-ice surface composition. Crater densities on Nix and Hydra imply surface ages of at least 4 billion years. The small moons rotate much faster than synchronous, with rotational poles clustered nearly orthogonal to the common pole directions of Pluto and Charon. These results reinforce the hypothesis that the small moons formed in the aftermath of a collision that produced the Pluto-Charon binary.
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Affiliation(s)
- H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA.
| | - M W Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B J Buratti
- NASA Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - W M Grundy
- Lowell Observatory, Flagstaff, AZ 86001, USA
| | - T R Lauer
- National Optical Astronomy Observatory, Tucson, AZ 26732, USA
| | - C B Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A H Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S B Porter
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - J R Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S A Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A J Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - W B McKinnon
- Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
| | - J M Moore
- Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - S J Robbins
- Southwest Research Institute, Boulder, CO 80302, USA
| | - P Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | - K N Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - O S Barnouin
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A F Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C M Ernst
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C M Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D E Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - A W Lunsford
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D C Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - D P Hamilton
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - D E Kaufmann
- Southwest Research Institute, Boulder, CO 80302, USA
| | - K Ennico
- Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - L A Young
- Southwest Research Institute, Boulder, CO 80302, USA
| | - R A Beyer
- SETI Institute, Mountain View, CA 94043, USA. Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - R P Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - V J Bray
- University of Arizona, Tucson, AZ 85721, USA
| | - A L Chaikin
- Independent science writer, Arlington, VT, USA
| | - J C Cook
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D P Cruikshank
- Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - C M Dalle Ore
- Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - A M Earle
- University of Arizona, Tucson, AZ 85721, USA
| | - G R Gladstone
- Southwest Research Institute, San Antonio, TX 78238, USA
| | - C J A Howett
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - F Nimmo
- University of California, Santa Cruz, CA 95064, USA
| | - J Wm Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S Philippe
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - S Protopapa
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - H J Reitsema
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B Schmitt
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - T Stryk
- Roane State Community College, Oak Ridge, TN 37830, USA
| | - M E Summers
- George Mason University, Fairfax, VA 22030, USA
| | - C C C Tsang
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H H B Throop
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - O L White
- Space Science Division, NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - A M Zangari
- Southwest Research Institute, Boulder, CO 80302, USA
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14
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Bagenal F, Horányi M, McComas DJ, McNutt RL, Elliott HA, Hill ME, Brown LE, Delamere PA, Kollmann P, Krimigis SM, Kusterer M, Lisse CM, Mitchell DG, Piquette M, Poppe AR, Strobel DF, Szalay JR, Valek P, Vandegriff J, Weidner S, Zirnstein EJ, Stern SA, Ennico K, Olkin CB, Weaver HA, Young LA. Pluto's interaction with its space environment: Solar wind, energetic particles, and dust. Science 2016; 351:aad9045. [PMID: 26989259 DOI: 10.1126/science.aad9045] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers(-3) for the dust density in the Pluto system.
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Affiliation(s)
- F Bagenal
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80600, USA.
| | - M Horányi
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80600, USA
| | - D J McComas
- Southwest Research Institute, San Antonio, TX 78228, USA. University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - R L McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - H A Elliott
- Southwest Research Institute, San Antonio, TX 78228, USA
| | - M E Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - L E Brown
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - P Kollmann
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S M Krimigis
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA. Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
| | - M Kusterer
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C M Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D G Mitchell
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M Piquette
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80600, USA
| | - A R Poppe
- Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
| | - D F Strobel
- Johns Hopkins University, Baltimore, MD 21218, USA
| | - J R Szalay
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80600, USA. Southwest Research Institute, Boulder, CO 80302, USA
| | - P Valek
- Southwest Research Institute, San Antonio, TX 78228, USA
| | - J Vandegriff
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S Weidner
- Southwest Research Institute, San Antonio, TX 78228, USA
| | - E J Zirnstein
- Southwest Research Institute, San Antonio, TX 78228, USA
| | - S A Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - K Ennico
- NASA Ames Research Center, Moffett Field, CA 94035, USA
| | - C B Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H A Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - L A Young
- Southwest Research Institute, Boulder, CO 80302, USA
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15
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Grundy WM, Binzel RP, Buratti BJ, Cook JC, Cruikshank DP, Dalle Ore CM, Earle AM, Ennico K, Howett CJA, Lunsford AW, Olkin CB, Parker AH, Philippe S, Protopapa S, Quirico E, Reuter DC, Schmitt B, Singer KN, Verbiscer AJ, Beyer RA, Buie MW, Cheng AF, Jennings DE, Linscott IR, Parker JW, Schenk PM, Spencer JR, Stansberry JA, Stern SA, Throop HB, Tsang CCC, Weaver HA, Weigle GE, Young LA. Surface compositions across Pluto and Charon. Science 2016; 351:aad9189. [DOI: 10.1126/science.aad9189] [Citation(s) in RCA: 209] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
| | - R. P. Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - B. J. Buratti
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - J. C. Cook
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D. P. Cruikshank
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - C. M. Dalle Ore
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
- Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - A. M. Earle
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - K. Ennico
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | | | - A. W. Lunsford
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - C. B. Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A. H. Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S. Philippe
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - S. Protopapa
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - E. Quirico
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - D. C. Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - B. Schmitt
- Université Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble, France
| | - K. N. Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A. J. Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - R. A. Beyer
- NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
- Carl Sagan Center, SETI Institute, Mountain View, CA 94043, USA
| | - M. W. Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - A. F. Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D. E. Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | | | - J. Wm. Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - P. M. Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | - J. R. Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - S. A. Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | | | - H. A. Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - G. E. Weigle
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - L. A. Young
- Southwest Research Institute, Boulder, CO 80302, USA
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16
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White NJ, Mehic E, Wang X, Chien D, Lim E, St John AE, Stern SA, Mourad PD, Rieger M, Fries D, Martinowitz U. Rediscovering the wound hematoma as a site of hemostasis during major arterial hemorrhage. J Thromb Haemost 2015; 13:2202-9. [PMID: 26414624 PMCID: PMC4777306 DOI: 10.1111/jth.13158] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/17/2015] [Indexed: 11/30/2022]
Abstract
BACKGROUND Treatments for major internal bleeding after injury include permissive hypotension to decrease the rate of blood loss, intravenous infusion of plasma or clotting factors to improve clot formation, and rapid surgical hemostasis or arterial embolization to control bleeding vessels. Yet, little is known regarding major internal arterial hemostasis, or how these commonly used treatments might influence hemostasis. OBJECTIVES (i) To use a swine model of femoral artery bleeding to understand the perivascular hemostatic response to contained arterial hemorrhage. (ii) To directly confirm the association between hemodynamics and bleeding velocity. (iii) To observe the feasibility of delivering an activated clotting factor directly to internal sites of bleeding using a simplified angiographic approach. METHODS Ultrasound was used to measure bleeding velocity and in vivo clot formation by elastography in a swine model of contained femoral artery bleeding with fluid resuscitation. A swine model of internal pelvic and axillary artery hemorrhage was also used to demonstrate the feasibility of local delivery of an activated clotting factor. RESULTS In this model, clots formed slowly within the peri-wound hematoma, but eventually contained the bleeding. Central hemodynamics correlated positively with bleeding velocity. Infusion of recombinant human activated factor VII into the injured artery near the site of major internal hemorrhage in the pelvis and axillae was feasible. CONCLUSIONS We rediscovered that clot formation within the peri-wound hematoma is an integral component of hemostasis and a feasible target for the treatment of major internal bleeding using activated clotting factors delivered using a simplified angiographic approach.
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Affiliation(s)
- N J White
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - E Mehic
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
| | - X Wang
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - D Chien
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - E Lim
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - A E St John
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - S A Stern
- Division of Emergency Medicine, University of Washington, Seattle, WA, USA
| | - P D Mourad
- Department of Neurological Surgery, University of Washington, Seattle, WA, USA
- Division of Engineering and Mathematics, University of Washington, Bothell, WA, USA
| | - M Rieger
- Department of Diagnostic & Interventional Radiology, Medical Clinic Innsbruck, Innsbruck, Austria
| | - D Fries
- Clinical Department for General and Surgical Intensive Care Medicine of the Clinic for Anaesthesia and General Intensive Care Medicine, Medical Clinic Innsbruck, Innsbruck, Austria
| | - U Martinowitz
- Department for Hematology, TelHashomer University Hospital, Telaviv, Israel
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17
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Stern SA, Bagenal F, Ennico K, Gladstone GR, Grundy WM, McKinnon WB, Moore JM, Olkin CB, Spencer JR, Weaver HA, Young LA, Andert T, Andrews J, Banks M, Bauer B, Bauman J, Barnouin OS, Bedini P, Beisser K, Beyer RA, Bhaskaran S, Binzel RP, Birath E, Bird M, Bogan DJ, Bowman A, Bray VJ, Brozovic M, Bryan C, Buckley MR, Buie MW, Buratti BJ, Bushman SS, Calloway A, Carcich B, Cheng AF, Conard S, Conrad CA, Cook JC, Cruikshank DP, Custodio OS, Dalle Ore CM, Deboy C, Dischner ZJB, Dumont P, Earle AM, Elliott HA, Ercol J, Ernst CM, Finley T, Flanigan SH, Fountain G, Freeze MJ, Greathouse T, Green JL, Guo Y, Hahn M, Hamilton DP, Hamilton SA, Hanley J, Harch A, Hart HM, Hersman CB, Hill A, Hill ME, Hinson DP, Holdridge ME, Horanyi M, Howard AD, Howett CJA, Jackman C, Jacobson RA, Jennings DE, Kammer JA, Kang HK, Kaufmann DE, Kollmann P, Krimigis SM, Kusnierkiewicz D, Lauer TR, Lee JE, Lindstrom KL, Linscott IR, Lisse CM, Lunsford AW, Mallder VA, Martin N, McComas DJ, McNutt RL, Mehoke D, Mehoke T, Melin ED, Mutchler M, Nelson D, Nimmo F, Nunez JI, Ocampo A, Owen WM, Paetzold M, Page B, Parker AH, Parker JW, Pelletier F, Peterson J, Pinkine N, Piquette M, Porter SB, Protopapa S, Redfern J, Reitsema HJ, Reuter DC, Roberts JH, Robbins SJ, Rogers G, Rose D, Runyon K, Retherford KD, Ryschkewitsch MG, Schenk P, Schindhelm E, Sepan B, Showalter MR, Singer KN, Soluri M, Stanbridge D, Steffl AJ, Strobel DF, Stryk T, Summers ME, Szalay JR, Tapley M, Taylor A, Taylor H, Throop HB, Tsang CCC, Tyler GL, Umurhan OM, Verbiscer AJ, Versteeg MH, Vincent M, Webbert R, Weidner S, Weigle GE, White OL, Whittenburg K, Williams BG, Williams K, Williams S, Woods WW, Zangari AM, Zirnstein E. The Pluto system: Initial results from its exploration by New Horizons. Science 2015; 350:aad1815. [DOI: 10.1126/science.aad1815] [Citation(s) in RCA: 367] [Impact Index Per Article: 40.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- S. A. Stern
- Southwest Research Institute, Boulder, CO 80302, USA
| | - F. Bagenal
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - K. Ennico
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | | | | | - W. B. McKinnon
- Department of Earth and Planetary Sciences, Washington University, St. Louis, MO 63130, USA
| | - J. M. Moore
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - C. B. Olkin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J. R. Spencer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H. A. Weaver
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - L. A. Young
- Southwest Research Institute, Boulder, CO 80302, USA
| | - T. Andert
- Universität der Bundeswehr München, Neubiberg 85577, Germany
| | - J. Andrews
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M. Banks
- Planetary Science Institute, Tucson, AZ 85719, USA
| | - B. Bauer
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J. Bauman
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - O. S. Barnouin
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - P. Bedini
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - K. Beisser
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - R. A. Beyer
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - S. Bhaskaran
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - R. P. Binzel
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - E. Birath
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M. Bird
- University of Bonn, Bonn D-53113, Germany
| | - D. J. Bogan
- NASA Headquarters (retired), Washington, DC 20546, USA
| | - A. Bowman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - V. J. Bray
- University of Arizona, Tucson, AZ 85721, USA
| | - M. Brozovic
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - C. Bryan
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - M. R. Buckley
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. W. Buie
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B. J. Buratti
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - S. S. Bushman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A. Calloway
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - B. Carcich
- Cornell University, Ithaca, NY 14853, USA
| | - A. F. Cheng
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S. Conard
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C. A. Conrad
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J. C. Cook
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D. P. Cruikshank
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - O. S. Custodio
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C. M. Dalle Ore
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - C. Deboy
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - P. Dumont
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - A. M. Earle
- Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - H. A. Elliott
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - J. Ercol
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C. M. Ernst
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T. Finley
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S. H. Flanigan
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - G. Fountain
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. J. Freeze
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T. Greathouse
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - J. L. Green
- NASA Headquarters, Washington, DC 20546, USA
| | - Y. Guo
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. Hahn
- Rheinisches Institut für Umweltforschung an der Universität zu Köln, Cologne 50931, Germany
| | - D. P. Hamilton
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - S. A. Hamilton
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - J. Hanley
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - A. Harch
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H. M. Hart
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C. B. Hersman
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A. Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. E. Hill
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D. P. Hinson
- Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA
| | - M. E. Holdridge
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. Horanyi
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - A. D. Howard
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA
| | | | | | - R. A. Jacobson
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - D. E. Jennings
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - J. A. Kammer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - H. K. Kang
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - P. Kollmann
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S. M. Krimigis
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D. Kusnierkiewicz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T. R. Lauer
- National Optical Astronomy Observatory, Tucson, AZ 26732, USA
| | - J. E. Lee
- NASA Marshall Space Flight Center, Huntsville, AL 35812, USA
| | - K. L. Lindstrom
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | - C. M. Lisse
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A. W. Lunsford
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - V. A. Mallder
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - N. Martin
- Southwest Research Institute, Boulder, CO 80302, USA
| | - D. J. McComas
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - R. L. McNutt
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D. Mehoke
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - T. Mehoke
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - E. D. Melin
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. Mutchler
- Space Telescope Science Institute, Baltimore, MD 21218, USA
| | - D. Nelson
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - F. Nimmo
- University of California, Santa Cruz, CA 95064, USA
| | - J. I. Nunez
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A. Ocampo
- NASA Headquarters, Washington, DC 20546, USA
| | - W. M. Owen
- NASA Jet Propulsion Laboratory, La Cañada Flintridge, CA 91011, USA
| | - M. Paetzold
- Rheinisches Institut für Umweltforschung an der Universität zu Köln, Cologne 50931, Germany
| | - B. Page
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - A. H. Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - J. W. Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - J. Peterson
- Southwest Research Institute, Boulder, CO 80302, USA
| | - N. Pinkine
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. Piquette
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - S. B. Porter
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S. Protopapa
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - J. Redfern
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - D. C. Reuter
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - J. H. Roberts
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S. J. Robbins
- Southwest Research Institute, Boulder, CO 80302, USA
| | - G. Rogers
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - D. Rose
- Southwest Research Institute, Boulder, CO 80302, USA
| | - K. Runyon
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | | | - P. Schenk
- Lunar and Planetary Institute, Houston, TX 77058, USA
| | - E. Schindhelm
- Southwest Research Institute, Boulder, CO 80302, USA
| | - B. Sepan
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - M. R. Showalter
- Search for Extraterrestrial Intelligence Institute, Mountain View, CA 94043, USA
| | - K. N. Singer
- Southwest Research Institute, Boulder, CO 80302, USA
| | - M. Soluri
- Michael Soluri Photography, New York, NY 10014, USA
| | | | - A. J. Steffl
- Southwest Research Institute, Boulder, CO 80302, USA
| | | | - T. Stryk
- Roane State Community College, Jamestown, TN 38556, USA
| | | | - J. R. Szalay
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303, USA
| | - M. Tapley
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - A. Taylor
- KinetX Aerospace, Tempe, AZ 85284, USA
| | - H. Taylor
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - H. B. Throop
- Planetary Science Institute, Tucson, AZ 85719, USA
| | | | - G. L. Tyler
- Stanford University, Stanford, CA 94305, USA
| | - O. M. Umurhan
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - A. J. Verbiscer
- Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA
| | - M. H. Versteeg
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - M. Vincent
- Southwest Research Institute, Boulder, CO 80302, USA
| | - R. Webbert
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - S. Weidner
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - G. E. Weigle
- Southwest Research Institute, San Antonio, TX 28510, USA
| | - O. L. White
- National Aeronautics and Space Administration (NASA) Ames Research Center, Space Science Division, Moffett Field, CA 94035, USA
| | - K. Whittenburg
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | | | | | - S. Williams
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - W. W. Woods
- Stanford University, Stanford, CA 94305, USA
| | - A. M. Zangari
- Southwest Research Institute, Boulder, CO 80302, USA
| | - E. Zirnstein
- Southwest Research Institute, San Antonio, TX 28510, USA
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18
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Schmidt BE, Thomas PC, Bauer JM, Li JY, McFadden LA, Mutchler MJ, Radcliffe SC, Rivkin AS, Russell CT, Parker JW, Stern SA. The Shape and Surface Variation of 2 Pallas from the Hubble Space Telescope. Science 2009; 326:275-8. [DOI: 10.1126/science.1177734] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- B. E. Schmidt
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095, USA
| | - P. C. Thomas
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - J. M. Bauer
- Jet Propulsion Laboratory, Pasadena, CA 91109, USA
| | - J.-Y. Li
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - L. A. McFadden
- Department of Astronomy, University of Maryland, College Park, MD 20742, USA
| | - M. J. Mutchler
- Space Telescope Science Institute (STScI), Baltimore, MD 80302, USA
| | | | - A. S. Rivkin
- Applied Physics Laboratory, Laurel, MD 20723, USA
| | - C. T. Russell
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90095, USA
| | - J. Wm. Parker
- Southwest Research Institute, Boulder, CO 80302, USA
| | - S. A. Stern
- Southwest Research Institute, Boulder, CO 80302, USA
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19
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Spencer JR, Stern SA, Cheng AF, Weaver HA, Reuter DC, Retherford K, Lunsford A, Moore JM, Abramov O, Lopes RMC, Perry JE, Kamp L, Showalter M, Jessup KL, Marchis F, Schenk PM, Dumas C. Io volcanism seen by new horizons: a major eruption of the Tvashtar volcano. Science 2007; 318:240-3. [PMID: 17932290 DOI: 10.1126/science.1147621] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Jupiter's moon Io is known to host active volcanoes. In February and March 2007, the New Horizons spacecraft obtained a global snapshot of Io's volcanism. A 350-kilometer-high volcanic plume was seen to emanate from the Tvashtar volcano (62 degrees N, 122 degrees W), and its motion was observed. The plume's morphology and dynamics support nonballistic models of large Io plumes and also suggest that most visible plume particles condensed within the plume rather than being ejected from the source. In images taken in Jupiter eclipse, nonthermal visible-wavelength emission was seen from individual volcanoes near Io's sub-Jupiter and anti-Jupiter points. Near-infrared emission from the brightest volcanoes indicates minimum magma temperatures in the 1150- to 1335-kelvin range, consistent with basaltic composition.
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Affiliation(s)
- J R Spencer
- Southwest Research Institute, 1050 Walnut Street, Suite 300, Boulder, CO 80302, USA.
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20
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Grundy WM, Buratti BJ, Cheng AF, Emery JP, Lunsford A, McKinnon WB, Moore JM, Newman SF, Olkin CB, Reuter DC, Schenk PM, Spencer JR, Stern SA, Throop HB, Weaver HA. New horizons mapping of Europa and Ganymede. Science 2007; 318:234-7. [PMID: 17932288 DOI: 10.1126/science.1147623] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The New Horizons spacecraft observed Jupiter's icy satellites Europa and Ganymede during its flyby in February and March 2007 at visible and infrared wavelengths. Infrared spectral images map H2O ice absorption and hydrated contaminants, bolstering the case for an exogenous source of Europa's "non-ice" surface material and filling large gaps in compositional maps of Ganymede's Jupiter-facing hemisphere. Visual wavelength images of Europa extend knowledge of its global pattern of arcuate troughs and show that its surface scatters light more isotropically than other icy satellites.
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Affiliation(s)
- W M Grundy
- Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA.
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21
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Reuter DC, Simon-Miller AA, Lunsford A, Baines KH, Cheng AF, Jennings DE, Olkin CB, Spencer JR, Stern SA, Weaver HA, Young LA. Jupiter cloud composition, stratification, convection, and wave motion: a view from new horizons. Science 2007; 318:223-5. [PMID: 17932284 DOI: 10.1126/science.1147618] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Several observations of Jupiter's atmosphere made by instruments on the New Horizons spacecraft have implications for the stability and dynamics of Jupiter's weather layer. Mesoscale waves, first seen by Voyager, have been observed at a spatial resolution of 11 to 45 kilometers. These waves have a 300-kilometer wavelength and phase velocities greater than the local zonal flow by 100 meters per second, much higher than predicted by models. Additionally, infrared spectral measurements over five successive Jupiter rotations at spatial resolutions of 200 to 140 kilometers have shown the development of transient ammonia ice clouds (lifetimes of 40 hours or less) in regions of strong atmospheric upwelling. Both of these phenomena serve as probes of atmospheric dynamics below the visible cloud tops.
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Affiliation(s)
- D C Reuter
- NASA Goddard Space Flight Center, Code 693, Greenbelt, MD 20771, USA.
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22
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McNutt RL, Haggerty DK, Hill ME, Krimigis SM, Livi S, Ho GC, Gurnee RS, Mauk BH, Mitchell DG, Roelof EC, McComas DJ, Bagenal F, Elliott HA, Brown LE, Kusterer M, Vandegriff J, Stern SA, Weaver HA, Spencer JR, Moore JM. Energetic Particles in the Jovian Magnetotail. Science 2007; 318:220-2. [PMID: 17932283 DOI: 10.1126/science.1148025] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- R. L. McNutt
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - D. K. Haggerty
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - M. E. Hill
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - S. M. Krimigis
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - S. Livi
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - G. C. Ho
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - R. S. Gurnee
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - B. H. Mauk
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - D. G. Mitchell
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - E. C. Roelof
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - D. J. McComas
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - F. Bagenal
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - H. A. Elliott
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - L. E. Brown
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - M. Kusterer
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - J. Vandegriff
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - S. A. Stern
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - H. A. Weaver
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - J. R. Spencer
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
| | - J. M. Moore
- Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723, USA
- Academy of Athens, 28 Panapistimiou, 10679 Athens, Greece
- Southwest Research Institute, San Antonio, TX 78228, USA
- Laboratory of Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309–0392, USA
- NASA Headquarters, Washington, DC 20546–0001, USA
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23
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Retherford KD, Spencer JR, Stern SA, Saur J, Strobel DF, Steffl AJ, Gladstone GR, Weaver HA, Cheng AF, Parker JW, Slater DC, Versteeg MH, Davis MW, Bagenal F, Throop HB, Lopes RMC, Reuter DC, Lunsford A, Conard SJ, Young LA, Moore JM. Io's Atmospheric Response to Eclipse: UV Aurorae Observations. Science 2007; 318:237-40. [DOI: 10.1126/science.1147594] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- K. D. Retherford
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - J. R. Spencer
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - S. A. Stern
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - J. Saur
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - D. F. Strobel
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - A. J. Steffl
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - G. R. Gladstone
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - H. A. Weaver
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - A. F. Cheng
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - J. Wm. Parker
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - D. C. Slater
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - M. H. Versteeg
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - M. W. Davis
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - F. Bagenal
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - H. B. Throop
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - R. M. C. Lopes
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - D. C. Reuter
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - A. Lunsford
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - S. J. Conard
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - L. A. Young
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
| | - J. M. Moore
- Southwest Research Institute, San Antonio, TX 78228, USA
- Southwest Research Institute, Boulder, CO 80302, USA
- NASA Headquarters, Washington, DC 20546, USA
- University of Cologne, 50923 Koln, Germany
- The Johns Hopkins University, Baltimore, MD 21218, USA
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Affiliation(s)
- S. A. Stern
- a Department of Chemical Engineering and Materials Science , Syracuse University , Syracuse, New York
| | - S. K. Sen
- a Department of Chemical Engineering and Materials Science , Syracuse University , Syracuse, New York
| | - A. K. Rao
- a Department of Chemical Engineering and Materials Science , Syracuse University , Syracuse, New York
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Affiliation(s)
- S. A. Stern
- a Department of Chemical Engineering and Metallurgy , Syracuse University , Syracuse, New York
| | - S. M. Fang
- a Department of Chemical Engineering and Metallurgy , Syracuse University , Syracuse, New York
| | - R. M. Jobbins
- a Department of Chemical Engineering and Metallurgy , Syracuse University , Syracuse, New York
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Stern SA, Weaver HA, Steffl AJ, Mutchler MJ, Merline WJ, Buie MW, Young EF, Young LA, Spencer JR. A giant impact origin for Pluto's small moons and satellite multiplicity in the Kuiper belt. Nature 2006; 439:946-8. [PMID: 16495992 DOI: 10.1038/nature04548] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Accepted: 12/20/2005] [Indexed: 11/09/2022]
Abstract
The two newly discovered satellites of Pluto (P1 and P2) have masses that are small compared to both Pluto and Charon-that is, between 5 x 10(-4) and 1 x 10(-5) of Pluto's mass, and between 5 x 10(-3) and 1 x 10(-4) of Charon's mass. This discovery, combined with the constraints on the absence of more distant satellites of Pluto, reveal that Pluto and its moons comprise an unusual, highly compact, quadruple system. These facts naturally raise the question of how this puzzling satellite system came to be. Here we show that P1 and P2's proximity to Pluto and Charon, the fact that P1 and P2 are on near-circular orbits in the same plane as Pluto's large satellite Charon, along with their apparent locations in or near high-order mean-motion resonances, all probably result from their being constructed from collisional ejecta that originated from the Pluto-Charon formation event. We also argue that dust-ice rings of variable optical depths form sporadically in the Pluto system, and that rich satellite systems may be found--perhaps frequently--around other large Kuiper belt objects.
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Affiliation(s)
- S A Stern
- Southwest Research Institute, 1050 Walnut Street, Suite 400, Boulder, Colorado 80302, USA.
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Weaver HA, Stern SA, Mutchler MJ, Steffl AJ, Buie MW, Merline WJ, Spencer JR, Young EF, Young LA. Discovery of two new satellites of Pluto. Nature 2006; 439:943-5. [PMID: 16495991 DOI: 10.1038/nature04547] [Citation(s) in RCA: 128] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2005] [Accepted: 12/22/2005] [Indexed: 11/09/2022]
Abstract
Pluto's first known satellite, Charon, was discovered in 1978. It has a diameter (approximately 1,200 km) about half that of Pluto, which makes it larger, relative to its primary, than any other moon in the Solar System. Previous searches for other satellites around Pluto have been unsuccessful, but they were not sensitive to objects less, similar150 km in diameter and there are no fundamental reasons why Pluto should not have more satellites. Here we report the discovery of two additional moons around Pluto, provisionally designated S/2005 P 1 (hereafter P1) and S/2005 P 2 (hereafter P2), which makes Pluto the first Kuiper belt object known to have multiple satellites. These new satellites are much smaller than Charon, with estimates of P1's diameter ranging from 60 km to 165 km, depending on the surface reflectivity; P2 is about 20 per cent smaller than P1. Although definitive orbits cannot be derived, both new satellites appear to be moving in circular orbits in the same orbital plane as Charon, with orbital periods of approximately 38 days (P1) and approximately 25 days (P2).
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Affiliation(s)
- H A Weaver
- The Johns Hopkins University Applied Physics Laboratory, Space Department, 11100 Johns Hopkins Road, Laurel, Maryland 20723-6099, USA.
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Thomas PC, Parker JW, McFadden LA, Russell CT, Stern SA, Sykes MV, Young EF. Differentiation of the asteroid Ceres as revealed by its shape. Nature 2005; 437:224-6. [PMID: 16148926 DOI: 10.1038/nature03938] [Citation(s) in RCA: 239] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2005] [Accepted: 06/10/2005] [Indexed: 11/08/2022]
Abstract
The accretion of bodies in the asteroid belt was halted nearly 4.6 billion years ago by the gravitational influence of the newly formed giant planet Jupiter. The asteroid belt therefore preserves a record of both this earliest epoch of Solar System formation and variation of conditions within the solar nebula. Spectral features in reflected sunlight indicate that some asteroids have experienced sufficient thermal evolution to differentiate into layered structures. The second most massive asteroid--4 Vesta--has differentiated to a crust, mantle and core. 1 Ceres, the largest and most massive asteroid, has in contrast been presumed to be homogeneous, in part because of its low density, low albedo and relatively featureless visible reflectance spectrum, similar to carbonaceous meteorites that have suffered minimal thermal processing. Here we show that Ceres has a shape and smoothness indicative of a gravitationally relaxed object. Its shape is significantly less flattened than that expected for a homogeneous object, but is consistent with a central mass concentration indicative of differentiation. Possible interior configurations include water-ice-rich mantles over a rocky core.
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Affiliation(s)
- P C Thomas
- Center for Radiophysics and Space Research, Cornell University, Ithaca, New York 14853, USA.
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Bertaux JL, Leblanc F, Witasse O, Quemerais E, Lilensten J, Stern SA, Sandel B, Korablev O. Discovery of an aurora on Mars. Nature 2005; 435:790-4. [PMID: 15944698 DOI: 10.1038/nature03603] [Citation(s) in RCA: 183] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2005] [Accepted: 03/29/2005] [Indexed: 11/09/2022]
Abstract
In the high-latitude regions of Earth, aurorae are the often-spectacular visual manifestation of the interaction between electrically charged particles (electrons, protons or ions) with the neutral upper atmosphere, as they precipitate along magnetic field lines. More generally, auroral emissions in planetary atmospheres "are those that result from the impact of particles other than photoelectrons" (ref. 1). Auroral activity has been found on all four giant planets possessing a magnetic field (Jupiter, Saturn, Uranus and Neptune), as well as on Venus, which has no magnetic field. On the nightside of Venus, atomic O emissions at 130.4 nm and 135.6 nm appear in bright patches of varying sizes and intensities, which are believed to be produced by electrons with energy <300 eV (ref. 7). Here we report the discovery of an aurora in the martian atmosphere, using the ultraviolet spectrometer SPICAM on board Mars Express. It corresponds to a distinct type of aurora not seen before in the Solar System: it is unlike aurorae at Earth and the giant planets, which lie at the foot of the intrinsic magnetic field lines near the magnetic poles, and unlike venusian auroras, which are diffuse, sometimes spreading over the entire disk. Instead, the martian aurora is a highly concentrated and localized emission controlled by magnetic field anomalies in the martian crust.
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Affiliation(s)
- Jean-Loup Bertaux
- Service d'Aéronomie du CNRS/IPSL, BP 3, Verrières-le-Buisson, 91371, France.
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Bertaux JL, Leblanc F, Perrier S, Quemerais E, Korablev O, Dimarellis E, Reberac A, Forget F, Simon PC, Stern SA, Sandel B. Nightglow in the upper atmosphere of Mars and implications for atmospheric transport. Science 2005; 307:566-9. [PMID: 15681381 DOI: 10.1126/science.1106957] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We detected light emissions in the nightside martian atmosphere with the SPICAM (spectroscopy for the investigation of the characteristics of the atmosphere of Mars) ultraviolet (UV) spectrometer on board the Mars Express. The UV spectrum of this nightglow is composed of hydrogen Lyman alpha emission (121.6 nanometers) and the gamma and delta bands of nitric oxide (NO) (190 to 270 nanometers) produced when N and O atoms combine to produce the NO molecule. N and O atoms are produced by extreme UV photodissociation of O2, CO2, and N2 in the dayside upper atmosphere and transported to the night side. The NO emission is brightest in the winter south polar night because of continuous downward transport of air in this region at night during winter and because of freezing at ground level.
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Affiliation(s)
- Jean-Loup Bertaux
- Service d'Aéronomie du CNRS/Institut Pierre-Simon Laplace (IPSL), BP.3, 91371, Verrières-le-Buisson, France.
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Soderblom LA, Becker TL, Bennett G, Boice DC, Britt DT, Brown RH, Buratti BJ, Isbell C, Giese B, Hare T, Hicks MD, Howington-Kraus E, Kirk RL, Lee M, Nelson RM, Oberst J, Owen TC, Rayman MD, Sandel BR, Stern SA, Thomas N, Yelle RV. Observations of comet 19P/Borrelly by the miniature integrated camera and spectrometer aboard Deep Space 1. Science 2002; 296:1087-91. [PMID: 11934989 DOI: 10.1126/science.1069527] [Citation(s) in RCA: 182] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The nucleus of the Jupiter-family comet 19P/Borrelly was closely observed by the Miniature Integrated Camera and Spectrometer aboard the Deep Space 1 spacecraft on 22 September 2001. The 8-kilometer-long body is highly variegated on a scale of 200 meters, exhibiting large albedo variations (0.01 to 0.03) and complex geologic relationships. Short-wavelength infrared spectra (1.3 to 2.6 micrometers) show a slope toward the red and a hot, dry surface (</=345 kelvin, with no trace of water ice or hydrated minerals), consistent with approximately 10% or less of the surface actively sublimating. Borrelly's coma exhibits two types of dust features: fans and highly collimated jets. At encounter, the near-nucleus coma was dominated by a prominent dust jet that resolved into at least three smaller jets emanating from a broad basin in the middle of the nucleus. Because the major dust jet remained fixed in orientation, it is evidently aligned near the rotation axis of the nucleus.
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Affiliation(s)
- L A Soderblom
- United States Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA.
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Mi Y, Zhou S, Stern SA. Representation of gas solubility in glassy polymers by a concentration-temperature superposition principle. Macromolecules 2002. [DOI: 10.1021/ma00009a037] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Abstract
For the past 4 decades, the standard approach to the trauma victim who is hypotensive from presumed hemorrhage has been to infuse large volumes of fluids as early and as rapidly as possible. The goals of this treatment strategy are rapid restoration of intravascular volume and vital signs towards normal, and maintenance of vital organ perfusion. The most recent laboratory studies and the only clinical trial evaluating the efficacy of these guidelines however, suggest that in the setting of uncontrolled hemorrhage, today's practice of aggressive fluid resuscitation may be harmful, resulting in increased hemorrhage volume and subsequently greater mortality. This has been demonstrated in animal models representative of penetrating trauma as well as those representative of blunt trauma. The data strongly suggest that limited or hypotensive resuscitation may be preferable for the trauma victim with the potential for ongoing uncontrolled hemorrhage. Limited resuscitation provides a mechanism of avoiding the detrimental effects associated with early aggressive resuscitation, while maintaining a level of tissue perfusion that although decreased from the normal physiologic range is adequate for short periods. Large randomized clinical trials are necessary to confirm this new laboratory data. Future research should focus on developing resuscitation methods that may actually enhance tissue perfusion during limited resuscitation and therefore offset its potential detrimental effects.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan, Ann Arbor, Michigan 48109-0303, USA.
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Zink BJ, Schultz CH, Stern SA, Mertz M, Wang X, Johnston P, Keep RF. Effects of ethanol and naltrexone in a model of traumatic brain injury with hemorrhagic shock. Alcohol Clin Exp Res 2001; 25:916-23. [PMID: 11410729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND Ethanol predisposes to traumatic injury and causes respiratory depression and cardiovascular compromise in models of traumatic brain injury (TBI) and hemorrhagic shock (HS). Endogenous opioids may play a role in ethanol intoxication and TBI. We studied the effects of ethanol and the opiate antagonist agent naltrexone (NTX) in a TBI/HS model. METHODS Fifty-six pigs (20 kg) were anesthetized with isoflurane, intubated, instrumented, and subjected to fluid percussion TBI with concurrent 30 ml/kg hemorrhage over 30 min. Seven groups were studied: Control, EtOH, NTX, INJ, INJ/EtOH, INJ/NTX, and INJ/EtOH/NTX. Ethanol (2 g/kg IV) was given preinjury, followed by infusion of 0.4 g/kg/hr. NTX 0.3 mg/kg intravenous was given 5 min postinjury. Parameters monitored for 120 min postinjury included minute ventilation (VE), blood pressure (MAP), cerebral perfusion pressure (CPP), cerebral venous lactate (Lac), arterial and cerebral venous blood gases, and brain tissue PtiO2. RESULTS Ethanol levels at injury were 220 mg/dL. Ethanol-treated animals had depression of hypercapnic ventilatory response, which was reversed by administration of naltrexone. MAP and CPP were significantly lower in injured animals, but were not significantly improved by NTX. Cerebral venous pH was lower and lactate was higher in ethanol-treated animals. CONCLUSION In this TBI/HS model, NTX reverses ethanol-induced depression of hypercapnic ventilatory response but does not improve MAP, CPP, or metabolic acidosis. This suggests that the respiratory effects of ethanol in TBI, but not the hemodynamic effects, may be mediated by opiate receptor activation.
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Affiliation(s)
- B J Zink
- University of Michigan Emergency Medicine Research Laboratory and Crosby Neurosurgical Laboratory Ann Arbor, Michigan 48109-0303, USA.
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Abstract
The Oort cloud of comets was formed by the ejection of icy planetesimals from the region of giant planets--Jupiter, Saturn, Uranus and Neptune--during their formation. Dynamical simulations have previously shown that comets reach the Oort cloud only after being perturbed into eccentric orbits that result in close encounters with the giant planets, which then eject them to distant orbits about 10(4) to 10(5) AU from the Sun (1 AU is the average Earth-Sun distance). All of the Oort cloud models constructed until now simulate its formation using only gravitational effects; these include the influence of the Sun, the planets and external perturbers such as passing stars and Galactic tides. Here we show that physical collisions between comets and small debris play a fundamental and hitherto unexplored role throughout most of the ejection process. For standard models of the protosolar nebula (starting with a minimum-mass nebula) we find that collisional evolution of comets is so severe that their erosional lifetimes are much shorter than the timescale for dynamical ejection. It therefore appears that collisions will prevent most comets escaping from most locations in the region of the giant planets until the disk mass there declines sufficiently that the dynamical ejection timescale is shorter than the collisional lifetime. One consequence is that the total mass of comets in the Oort cloud may be less than currently believed.
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Affiliation(s)
- S A Stern
- Space Studies Department, Southwest Research Institute, Boulder, Colorado 80302, USA.
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Stern SA, Wang X, Mertz M, Chowanski ZP, Remick DG, Kim HM, Dronen SC. Under-resuscitation of near-lethal uncontrolled hemorrhage: effects on mortality and end-organ function at 72 hours. Shock 2001; 15:16-23. [PMID: 11198352 DOI: 10.1097/00024382-200115010-00003] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Laboratory studies of uncontrolled hemorrhage demonstrate that under resuscitation (UR) improves short-term survival, but at the expense of tissue perfusion. The long-term effects of UR have not been studied. The purpose of this study was to evaluate survival and the incidence of end-organ injury (EOI), 3 days following moderate and severe UR of uncontrolled hemorrhage. Thirty-four swine (14-24 kg) were assigned to 4 groups: Groups I, II, and III were hemorrhaged to a pulse pressure = 5 mmHg in the presence of a 4-mm aortic tear: Group I (control; n = 6) was not resuscitated; Group II (n = 11) was severely under resuscitated (MAP [mean arterial pressure] = 40 mmHg) for 75 min; Group III (n = 9) was moderately under resuscitated (MAP = 60 mmHg) for 75 min. After 75 min, the aortotomy was repaired, and animals were resuscitated to baseline physiologic parameters. Group IV (sham; n = 8) was instrumented, but not hemorrhaged. Seventy-two-hour mortality was 100%, 36%, 22%, and 0% for Groups I through IV (P = .001 Fisher's exact). Cardiac indices, serum bicarbonate, and systemic oxygen delivery were significantly lower in Group II as compared to Group III during the 75 min of UR (P < 0.05; repeated measures ANOVA). By 72 h, physiologic parameters in surviving animals had returned to baseline levels. Measures of kidney, liver, neurologic, and pulmonary function did not change from baseline. There was no histologic evidence of EOI. In this model, 75 min of UR did not result in EOI. There was a trend toward greater survival, and tissue perfusion was better preserved with moderate as compared to severe UR.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan Medical Center, Ann Arbor 48109-0303, USA
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Stern SA, Kowalenko T, Younger J, Wang X, Dronen SC. Comparison of the effects of bolus vs. slow infusion of 7.5% NaCl/6% dextran-70 in a model of near-lethal uncontrolled hemorrhage. Shock 2000; 14:616-22. [PMID: 11131911 DOI: 10.1097/00024382-200014060-00008] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Bolus infusion of of 7.5% NaCl/6% dextran-70 (HSD-B) improves outcome from controlled hemorrhage. In contrast, HSD-B during uncontrolled hemorrhage increases bleeding and short-term mortality. The purpose of this study was to compare the effects of bolus vs. slow infusion of HSD in a near-fatal vascular injury hemorrhage model. Sixteen (15-20 kg) swine with 4-mm aortic tears were hemorrhaged to a pulse pressure of 5 mmHg. An ultrasonic flow probe was placed proximal to the aortic tear for continuous blood flow (AF) measurements. Group I (slow infusion; n = 8) was resuscitated with 8 mL/kg of HSD at 0.4 mL/kg/min. Group II (bolus infusion; n = 8) was resuscitated with 8 mL/kg of HSD at 1.33 mL/kg/min. In both groups, HSD infusion was followed by administration of 30 mL/kg of shed blood at 3 mL/kg/min. Hemorrhage volume and 90-min mortality were greater in group II (79+/-11 mL/kg; 75%) compared with group I (43+/-9 mL/kg; 12.5%) (P(Hem) < 0.001; P(Mort) = 0.04). Mean arterial pressure (MAP) and AF were greater in group II compared with group I during the first 15 min of resuscitation. In group I, MAP, AF, cardiac indices, and O2 delivery gradually returned to baseline levels and were significantly greater than group II at 30 min and throughout the remainder of the protocol. In this model of near-lethal uncontrolled hemorrhage, slow infusion of HSD restored cardiodynamics while minimizing hemorrhage volume and mortality. Resuscitation regimens that cause early increases in blood flow and pressure may result in greater hemorrhage and mortality than those regimens that yield comparable flow and pressure increases late in resuscitation.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan Medical Center, Ann Arbor 48109-0303, USA
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Abstract
OBJECTIVES 1) To evaluate residents' perceptions of the quality of training in basic academic skills and the availability and quality of research resources during residency; 2) to evaluate the association between these attitudes and choice of an academic career; and 3) to assess residents' attitudes toward the importance of postgraduate fellowship training for success in an academic career. METHODS A 15-item survey was administered to all U.S. emergency medicine (EM) residents in conjunction with the February 1997 American Board of Emergency Medicine (ABEM) In-service Examination. The survey assessed resident interest in a career in academic EM, and resident perception of the general quality of training in academic (research and teaching) skills. Residents were also asked to rate the quality of their training in the following specific academic skills: medical and grant writing, bedside teaching, lecturing, the use of computers, study design, statistics, and the use of audiovisual aids. Resident perceptions of the availability of the following resources were also assessed: teaching and research role models, data collection and analysis support, laboratory facilities, financial support of research, research fundamentals lectures, and computers. RESULTS The response rate was 93%. Forty-four percent of the respondents were interested in academic EM, 36.6% were undecided, and 19.6% were not interested in an academic career. On a scale of 1 (unprepared) to 5 (well prepared), the residents rated their overall preparedness for an academic career fairly high (3.97 [0.86]). In contrast, they perceived the quality of their training in the specific academic skill areas assessed and research resource availability to be only fair. Despite resident perception of relatively inadequate training in basic academic skills, only 24% of the respondents indicated that they believed fellowship training was important for success in an academic career. Logistic regression analyses demonstrated that participation in a research project in medical school, the length of the training program (4- vs 3-year), being a first-year resident, and a better perception of one's overall academic skill preparation were factors independently associated with having a greater interest in an academic career. CONCLUSIONS A relatively high percentage of residents initially express an interest in an academic career, but this interest wanes as residency progresses. A minority of residents believe that their training provides them with the specific skills needed to succeed in academics, or with adequate exposure to research resources or mentors. Emergency medicine may be able to increase the number of qualified academic faculty by recruiting medical students with prior research experience, and providing residents with better research training and role models.
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Affiliation(s)
- K Neacy
- Department of Emergency Medicine, Regions Medical Center, St. Paul, MN, USA
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Abstract
OBJECTIVES Resuscitation studies of hypertonic saline using controlled and uncontrolled hemorrhage models yield conflicting results with regard to efficacy. These disparate results reflect the use of models and resuscitation regimens that are not comparable between studies. This study evaluated the effects of comparable and clinically relevant resuscitation regimens of 7.5% sodium chloride/6% dextran 70 (HSD) and 0.9% sodium chloride (NS) in a near-fatal uncontrolled hemorrhage model. METHODS Thirty-six swine (14.2 to 21.4 kg) with 4-mm aortic tears were bled to a pulse pressure of 5 mm Hg (40-45 mL/kg). The animals were resuscitated with either NS or HSD administered in volumes that provided equivalent sodium loads at similar rates. Group II (n = 12) was resuscitated with 80 mL/kg of NS at a rate of 4 mL/kg/min. Group III (n = 12) received 9.6 mL/kg of HSD at a rate of 0.48 mL/kg/min. In both groups, crystalloid resuscitation was followed by shed blood infusion (30 mL/kg) at a rate of 2 mL/kg/min. Group I (controls; n = 12) were not resuscitated. RESULTS One-hour mortality was significantly greater in group I (92%) as compared with group II (33%) and group III (33%) (Fisher's exact test; p = 0.004). Intraperitoneal hemorrhage was significantly greater in group II (34 +/- 20 mL/kg) and group III (31 +/- 13 mL/ kg) as compared with group I (5 +/- 2 mL/kg) (ANOVA; p < 0.05). There was no significant difference in hemodynamic parameters between groups II and III. CONCLUSION In this model of severe uncontrolled hemorrhage, resuscitation with HSD or NS, administered in volumes that provided equivalent sodium loads at similar rates, had similar effects on mortality, hemodynamic parameters, and hemorrhage from the injury site.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan Medical Center, Ann Arbor 48109-0303, USA.
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Stern SA, Zink BJ, Mertz M, Wang X, Dronen SC. Effect of initially limited resuscitation in a combined model of fluid-percussion brain injury and severe uncontrolled hemorrhagic shock. J Neurosurg 2000; 93:305-14. [PMID: 10930018 DOI: 10.3171/jns.2000.93.2.0305] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Studies of isolated uncontrolled hemorrhage have indicated that initial limited resuscitation improves survival. Limited resuscitation has not been studied in combined traumatic brain injury and uncontrolled hemorrhage. In this study the authors evaluated the effects of limited resuscitation on outcome in combined fluid-percussion injury (FPI) and uncontrolled hemorrhage. METHODS Twenty-four swine weighing 17 to 24 kg each underwent FPI (3 atm) and hemorrhage to a mean arterial pressure (MAP) of 30 mm Hg in the presence of a 4-mm aortic tear. Group I (nine animals) was initially resuscitated to a goal MAP of 60 mm Hg; Group II (nine animals) was resuscitated to a goal MAP of 80 mm Hg; and Group III (control; six animals) was not resuscitated. After 60 minutes, the aortic hemorrhage was controlled and the animals were resuscitated to baseline physiological parameters and observed for 150 minutes. Mortality rates were 11%, 50%, and 100% for Groups I, II, and III, respectively (Fisher's exact test; p = 0.002). The total hemorrhage volume was greater in Group II (69+/-32 ml/kg), as compared with Group I (41+/-18 ml/kg) and Group III (37+/-3 ml/kg) according to analysis of variance (p < 0.05). In surviving animals, cerebral perfusion pressure, cerebral blood flow (CBF), cerebral venous O2 saturation (ScvO2), and cerebral metabolic rate of O2 did not differ among groups. Although CBF was approximately 50% of baseline during the period of limited resuscitation in Group I, ScvO2 remained greater than 60%, and arteriovenous O2 differences remained within normal limits. CONCLUSIONS In this model of FPI and uncontrolled hemorrhage, early aggressive resuscitation, which is currently recommended, resulted in increased hemorrhage and failure to optimize cerebrovascular parameters. In addition, a 60-minute period of moderate hypotension (MAP = 60 mm Hg) was well tolerated and did not compromise cerebrovascular hemodynamics, as evidenced by physiological parameters that remained within the limits of cerebral autoregulation.
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Affiliation(s)
- S A Stern
- Department of Emergency Medicine, University of Michigan Medical Center, Ann Arbor 48109-0303, USA.
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Abstract
OBJECTIVE Previous studies of traumatic brain injury (TBI) and hemorrhagic shock (HS) models, have shown cardiorespiratory depression in ethanol-treated animals. This study investigated the effects of ethanol (ET) on brain lactate concentrations and acidosis in a TBI/HS model. METHODS Anesthetized swine were instrumented and subjected to injury (INJ) consisting of fluid percussion TBI of 3 atm with concurrent 30 ml/kg graded hemorrhage over 30 min. Three groups were studied: Sham, INJ and INJ/ET. ET was given preinjury as a 2-g/kg i.v. bolus over 30 min, and an infusion of 0.4 g kg(-1) h(-1). Cardiorespiratory and cerebral physiologic data were monitored continuously for 150 min postinjury. Cerebral and renal blood flow was measured with colored microspheres. Brains were frozen in situ with liquid nitrogen. Lactate was measured with an enzymatic method. RESULTS ET levels at injury were 219+/-24 mg/dl. The INJ/ET group had increased mortality, impaired ventilation, and reduced renal blood flow. Brain (cortical) lactate levels were significantly higher and cerebral venous lactate concentrations were increased in the INJ/ET group during the postinjury period. Cerebral venous glucose was significantly higher in the INJ/ET group, and cerebral venous pH was significantly lower. CONCLUSION In this TBI/HS model, ethanol-induced increases in lactate concentrations in brain tissue and cerebral venous blood are associated with respiratory depression and reduced organ blood flow.
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Affiliation(s)
- B J Zink
- University of Michigan, Section of Emergency Medicine and the Emergency Medicine Research Laboratory, Ann Arbor, MI 48109-0303, USA.
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Abstract
OBJECTIVE To evaluate the impact of environmental factors on emergency medicine (EM) resident career choice. METHODS Program directors of all U.S. EM residencies were surveyed in November 1997. A 22-item questionnaire assessed resources allocated to research, fellowship availability, academic productivity of faculty and residents, and career choices of residency graduates. RESULTS The response rate was 83%. The program director (mean+/-SD) estimates of resident career choice were as follows: 27.8+/-19.1% pursued academic positions with emphasis on teaching, 5.4+/-9.8% pursued academic positions with emphasis on research, and 66.8+/-23.1%, pursued private practice positions. In addition, 5.70+/-6.13% of the residency graduates were estimated to seek fellowship training. Univariate analyses demonstrated that increasing departmental funding for research, having substantial resource availability (defined as having at least two of the following: dedicated laboratory space; support for a laboratory research technician/assistant, a clinical research nurse or study coordinator, a statistician, or an assistant with a PhD degree), a greater number of peer-reviewed publications by residents (r = 0.22; p = 0.08), and a greater number of peer-reviewed publications by faculty (r = 0.26; p = 0.04) positively correlated with the percentage of graduates who pursue academic research careers. Using multiple regression, however, increasing intramural funding and the presence of substantial resource availability were the only variables predictive of resident pursuit of an academic research career. CONCLUSION Modification of the EM training environment may influence the career choices of graduates. Specifically, greater commitment of departmental funds and support of resources for research may enhance the likelihood of a trainee's choosing an academic research career.
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Affiliation(s)
- S A Stern
- Section of Emergency Medicine, University of Michigan, Ann Arbor 48109-0303, USA.
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Zink BJ, Sheinberg MA, Wang X, Mertz M, Stern SA, Betz AL. Acute ethanol intoxication in a model of traumatic brain injury with hemorrhagic shock: effects on early physiological response. J Neurosurg 1998; 89:983-90. [PMID: 9833825 DOI: 10.3171/jns.1998.89.6.0983] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Traumatic brain injury (TBI) is exacerbated by hypotension and hypoventilation. Because previous studies have shown a potentiating effect of ethanol (EtOH) on TBI and hemorrhagic shock (HS), the authors investigated the effects of EtOH on the early physiological response to TBI with and without HS. METHODS Anesthetized swine, weighing approximately 20 kg each, underwent fluid-percussion TBI of 3 atm with or without 30 ml/kg hemorrhage for a period of 30 minutes. The mean arterial blood pressure, intracranial pressure, cerebral perfusion pressure (CPP), cardiac output, cerebral venous oxygen saturation, and metabolic parameters were monitored for 3 hours postinjury. Ventilation and the response to hypercapnia were also measured. Regional cerebral blood flow and renal blood flow were measured using dye-labeled microspheres. Five groups were studied: control, TBI, TBI/EtOH, TBI/HS, and TBI/HS/EtOH. The EtOH (3.5 g) was given intragastrically 100 minutes preinjury. The TBI/HS/EtOH group demonstrated a 3-hour mortality rate of 56% and postinjury apnea requiring ventilation in 44% of animals compared with 0% in all other groups. Minute ventilation and the hypercapnic ventilatory response were significantly reduced in the postinjury period in the TBI/HS/EtOH group. The animals in this group had significantly lower CPP and cardiac output in the first 60 minutes postinjury, as well as lower renal and cerebral blood flow. Postinjury cerebral venous lactate levels were higher, and cerebral venous pH was lower in the TBI/HS/EtOH group. CONCLUSIONS In this model of TBI, acute EtOH intoxication in the presence of HS potentiates the physiological and metabolic alterations that may contribute to secondary brain injury.
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Affiliation(s)
- B J Zink
- Department of Surgery, University of Michigan, Ann Arbor, USA.
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Affiliation(s)
- S. G. Charati
- Department of Chemical Engineering and Materials Science, Syracuse University, Syracuse, New York 13244
| | - S. A. Stern
- Department of Chemical Engineering and Materials Science, Syracuse University, Syracuse, New York 13244
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Younger JG, Taqi AS, Jost PF, Till GO, Johnson KJ, Stern SA, Hirschl RB. The pattern of early lung parenchymal and air space injury following acute blood loss. Acad Emerg Med 1998; 5:659-65. [PMID: 9678388 DOI: 10.1111/j.1553-2712.1998.tb02482.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
UNLABELLED Acute lung injury is a frequent clinical occurrence following blood loss and trauma. The nature of this injury remains poorly understood. OBJECTIVE To examine the relative parenchymal and intra-alveolar distribution of inflammation in a rat model of hemorrhage and resuscitation. METHODS Rats were anesthetized and subjected to hemorrhage followed by resuscitation with shed blood and saline. Myeloperoxidase activity of lung homogenates and cytology of bronchoalveolar lavage fluid were used to measure total lung and intra-alveolar neutrophil invasion. Extravasation of i.v.-administered [125I]-albumin was used to determine total lung and alveolar permeability. Permeability results were analyzed using their base-10 logarithmic transformations. RESULTS 86 animals were studied. Whole-lung myeloperoxidase activity was increased (control = 0.34 +/- 0.16 units, injured = 0.84 +/- 0.43 units, p < 0.01), while there was no difference in intra-alveolar leukocyte counts (injured = 1.85 +/- 1.30 x 10(5)/mL, control = 2.44 +/- 1.75 x 10(5)/mL, p = 0.40), suggesting that the cellular component of the injury was more severe in the intravascular and interstitial spaces. There was a strong trend toward increased permeability in the interstitial compartment, and a significant increase in permeability in the intra-alveolar compartment (whole-lung permeability: control = -0.27 +/- 0.19 units, injured = 0.10 +/- 0.55 units, p = 0.06; alveolar permeability: control = -2.00 +/- 0.47 units, injured = -1.32 +/- 0.49 units, p < 0.01), suggesting that the loss of integrity to macromolecules was not limited to the interstitium. CONCLUSION Hemorrhage and resuscitation resulted in an acute lung injury characterized by extravasation of intravascular protein into both the interstitium and the intra-alveolar space. Neutrophil invasion of the lung was demonstrable only in the interstitial compartment.
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Affiliation(s)
- J G Younger
- Emergency Medicine Research Laboratories and the Section of Emergency Medicine, the University of Michigan, Ann Arbor 48109-0303, USA.
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Abstract
OBJECTIVES Given that clinical and laboratory studies suggest that ethanol and hemorrhagic shock (HS) potentiate traumatic brain injury (TBI), the authors studied the effects of ethanol in a model of combined TBI and HS. METHODS A controlled porcine model of combined TBI and HS was evaluated for the effect of ethanol on survival time, hemodynamic function, and cerebral tissue perfusion. Anesthetized swine (17-24 kg) were instrumented, splenectomized, and subjected to fluid percussion TBI with concurrent 25-mL/kg graded hemorrhage over 30 minutes. Two groups were studied: control (n = 11) and ethanol (n = 11). Ethanol, 3.5 g/kg intragastric, was given 100 minutes prior to TBI/HS. Systemic and cerebral physiologic and metabolic parameters were monitored for 2 hours without resuscitation. Regional cerebral blood flow (rCBF) and renal blood flow were measured with dye-labeled microspheres. Data were analyzed with 2-sample t-test and repeated-measures ANOVA. RESULTS Ethanol levels at the time of injury were 162 +/- 68 mg/dL. Average TBI was 2.65 +/- 0.35 atm. Survival time was significantly shorter in the ethanol group (60 +/- 27 min vs 94 +/- 28 min, p = 0.011). The ethanol group had significantly lower mean arterial pressure, cerebral perfusion pressure, and cerebral venous O2 saturation in the postinjury period. Cerebral O2 extraction ratios and cerebral venous lactate levels were significantly higher in the ethanol group. A trend toward lower postinjury rCBF in all brain regions was observed in the ethanol group. CONCLUSION In this TBI/HS model, ethanol administration decreased survival time, impaired the hemodynamic response, and worsened measures of cerebral tissue perfusion.
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Affiliation(s)
- B J Zink
- Department of Surgery, University of Michigan, Ann Arbor, USA.
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Weaver HA, Feldman PD, A'Hearn MF, Arpigny C, Brandt JC, Festou MC, Haken M, McPhate JB, Stern SA, Tozzi GP. The activity and size of the nucleus of comet Hale-Bopp (C/1995 O1) [see comment]. Science 1997; 275:1900-4. [PMID: 9072959 DOI: 10.1126/science.275.5308.1900] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Analysis of Hubble Space Telescope (HST) images of comet Hale-Bopp (C/1995 O1) suggests that the effective diameter of the nucleus is between 27 to 42 kilometers, which is at least three times larger than that of comet P/Halley. The International Ultraviolet Explorer and HST spectra showed emissions from OH (a tracer of H2O) and CS (a tracer of CS2) starting in April 1996, and from the CO Cameron system (which primarily traces CO2) starting in June 1996. The variation of the H2O production rate with heliocentric distance was consistent with sublimation of an icy body near its subsolar point. The heliocentric variation in the production rates of CS2 and dust was different from that of H2O, which implies that H2O sublimation did not control the CS2 or dust production during these observations.
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Affiliation(s)
- H A Weaver
- Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218, USA
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Houde AY, Krishnakumar B, Charati SG, Stern SA. Permeability of dense (homogeneous) cellulose acetate membranes to methane, carbon dioxide, and their mixtures at elevated pressures. J Appl Polym Sci 1996. [DOI: 10.1002/(sici)1097-4628(19961226)62:13<2181::aid-app1>3.0.co;2-f] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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