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Rapin W, Dromart G, Clark BC, Schieber J, Kite ES, Kah LC, Thompson LM, Gasnault O, Lasue J, Meslin PY, Gasda PJ, Lanza NL. Sustained wet-dry cycling on early Mars. Nature 2023; 620:299-302. [PMID: 37558847 DOI: 10.1038/s41586-023-06220-3] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 05/15/2023] [Indexed: 08/11/2023]
Abstract
The presence of perennially wet surface environments on early Mars is well documented1,2, but little is known about short-term episodicity in the early hydroclimate3. Post-depositional processes driven by such short-term fluctuations may produce distinct structures, yet these are rarely preserved in the sedimentary record4. Incomplete geological constraints have led global models of the early Mars water cycle and climate to produce diverging results5,6. Here we report observations by the Curiosity rover at Gale Crater indicating that high-frequency wet-dry cycling occurred in early Martian surface environments. We observe exhumed centimetric polygonal ridges with sulfate enrichments, joined at Y-junctions, that record cracks formed in fresh mud owing to repeated wet-dry cycles of regular intensity. Instead of sporadic hydrological activity induced by impacts or volcanoes5, our findings point to a sustained, cyclic, possibly seasonal, climate on early Mars. Furthermore, as wet-dry cycling can promote prebiotic polymerization7,8, the Gale evaporitic basin may have been particularly conducive to these processes. The observed polygonal patterns are physically and temporally associated with the transition from smectite clays to sulfate-bearing strata, a globally distributed mineral transition1. This indicates that the Noachian-Hesperian transition (3.8-3.6 billion years ago) may have sustained an Earth-like climate regime and surface environments favourable to prebiotic evolution.
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Affiliation(s)
- W Rapin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France.
| | | | - B C Clark
- Space Science Institute, Boulder, CO, USA
| | - J Schieber
- Indiana University, Bloomington, IN, USA
| | - E S Kite
- University of Chicago, Chicago, IL, USA
| | - L C Kah
- University of Tennessee, Knoxville, TN, USA
| | - L M Thompson
- University of New Brunswick, Fredericton, NB, Canada
| | - O Gasnault
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France
| | - J Lasue
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France
| | - P-Y Meslin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, CNRS, CNES, Toulouse, France
| | - P J Gasda
- Los Alamos National Laboratory, Los Alamos, NM, USA
| | - N L Lanza
- Los Alamos National Laboratory, Los Alamos, NM, USA
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2
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Farley KA, Stack KM, Shuster DL, Horgan BHN, Hurowitz JA, Tarnas JD, Simon JI, Sun VZ, Scheller EL, Moore KR, McLennan SM, Vasconcelos PM, Wiens RC, Treiman AH, Mayhew LE, Beyssac O, Kizovski TV, Tosca NJ, Williford KH, Crumpler LS, Beegle LW, Bell JF, Ehlmann BL, Liu Y, Maki JN, Schmidt ME, Allwood AC, Amundsen HEF, Bhartia R, Bosak T, Brown AJ, Clark BC, Cousin A, Forni O, Gabriel TSJ, Goreva Y, Gupta S, Hamran SE, Herd CDK, Hickman-Lewis K, Johnson JR, Kah LC, Kelemen PB, Kinch KB, Mandon L, Mangold N, Quantin-Nataf C, Rice MS, Russell PS, Sharma S, Siljeström S, Steele A, Sullivan R, Wadhwa M, Weiss BP, Williams AJ, Wogsland BV, Willis PA, Acosta-Maeda TA, Beck P, Benzerara K, Bernard S, Burton AS, Cardarelli EL, Chide B, Clavé E, Cloutis EA, Cohen BA, Czaja AD, Debaille V, Dehouck E, Fairén AG, Flannery DT, Fleron SZ, Fouchet T, Frydenvang J, Garczynski BJ, Gibbons EF, Hausrath EM, Hayes AG, Henneke J, Jørgensen JL, Kelly EM, Lasue J, Le Mouélic S, Madariaga JM, Maurice S, Merusi M, Meslin PY, Milkovich SM, Million CC, Moeller RC, Núñez JI, Ollila AM, Paar G, Paige DA, Pedersen DAK, Pilleri P, Pilorget C, Pinet PC, Rice JW, Royer C, Sautter V, Schulte M, Sephton MA, Sharma SK, Sholes SF, Spanovich N, St Clair M, Tate CD, Uckert K, VanBommel SJ, Yanchilina AG, Zorzano MP. Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars. Science 2022; 377:eabo2196. [PMID: 36007009 DOI: 10.1126/science.abo2196] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe-Mg carbonates along grain boundaries indicate reactions with CO2-rich water, under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks were stored aboard Perseverance for potential return to Earth.
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Affiliation(s)
- K A Farley
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - K M Stack
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - D L Shuster
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA 94720, USA
| | - B H N Horgan
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - J A Hurowitz
- Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - J D Tarnas
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J I Simon
- Center for Isotope Cosmochemistry and Geochronology, Astromaterials Research and Exploration Science Division, NASA Johnson Space Center, Houston, TX 77058, USA
| | - V Z Sun
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - E L Scheller
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - K R Moore
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - S M McLennan
- Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - P M Vasconcelos
- School of Earth and Environmental Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - R C Wiens
- Planetary Exploration Team, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - A H Treiman
- Lunar and Planetary Institute, Universities Space Research Association, Houston, TX 77058, USA
| | - L E Mayhew
- Department of Geological Sciences, University of Colorado, Boulder, Boulder, CO 80309, USA
| | - O Beyssac
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Centre National de la Recherche Scientifique, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - T V Kizovski
- Department of Earth Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - N J Tosca
- Department of Earth Sciences, University of Cambridge, Cambridge CB2 3EQ, UK
| | - K H Williford
- Blue Marble Space Institute of Science, Seattle, WA 98104, USA
| | - L S Crumpler
- New Mexico Museum of Natural History and Science, Albuquerque, NM 8710, USA
| | - L W Beegle
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J F Bell
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - B L Ehlmann
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Y Liu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J N Maki
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M E Schmidt
- Department of Earth Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - A C Allwood
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - H E F Amundsen
- Center for Space Sensors and Systems, University of Oslo, 2007 Kjeller, Norway
| | - R Bhartia
- Photon Systems Inc., Covina, CA 91725, USA
| | - T Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - A J Brown
- Plancius Research, Severna Park, MD 21146, USA
| | - B C Clark
- Space Science Institute, Boulder, CO 80301, USA
| | - A Cousin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - O Forni
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - T S J Gabriel
- Astrogeology Science Center, US Geological Survey, Flagstaff, AZ 86001, USA
| | - Y Goreva
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - S Gupta
- Department of Earth Sciences and Engineering, Imperial College London, London SW7 2AZ, UK
| | - S-E Hamran
- Center for Space Sensors and Systems, University of Oslo, 2007 Kjeller, Norway
| | - C D K Herd
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, AB T6G 2E3, Canada
| | - K Hickman-Lewis
- Department of Earth Sciences, The Natural History Museum, London SW7 5BD, UK.,Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, 40126 Bologna, Italy
| | - J R Johnson
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - L C Kah
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA
| | - P B Kelemen
- Department of Earth and Environmental Sciences, Lamont Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA
| | - K B Kinch
- Niels Bohr Institute, University of Copenhagen, 1350 Copenhagen, Denmark
| | - L Mandon
- Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, Centre National de la Recherche Scientifique, Sorbonne Université, Université Paris Diderot, 92195 Meudon, France
| | - N Mangold
- Laboratoire de Planétologie et Géosciences, Centre National de la Recherche Scientifique, Nantes Université, Université Angers, 44000 Nantes, France
| | - C Quantin-Nataf
- Laboratoire de Géologie de Lyon: Terre, Université de Lyon, Université Claude Bernard Lyon1, Ecole Normale Supérieure de Lyon, Université Jean Monnet Saint Etienne, Centre National de la Recherche Scientifique, 69622 Villeurbanne, France
| | - M S Rice
- Department of Geology, Western Washington University, Bellingham, WA 98225 USA
| | - P S Russell
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - S Sharma
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - S Siljeström
- Department of Methodology, Textiles and Medical Technology, Research Institutes of Sweden, 11486 Stockholm, Sweden
| | - A Steele
- Earth and Planetary Laboratory, Carnegie Science, Washington, DC 20015, USA
| | - R Sullivan
- Cornell Center for Astrophysics and Planetary Science, Cornell University, Ithaca, NY 14853, USA
| | - M Wadhwa
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - B P Weiss
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.,Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - A J Williams
- Department of Geological Sciences, University of Florida, Gainesville, FL 32611, USA
| | - B V Wogsland
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996, USA
| | - P A Willis
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - T A Acosta-Maeda
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - P Beck
- Institut de Planétologie et Astrophysique de Grenoble, Centre National de la Recherche Scientifique, Université Grenoble Alpes, 38000 Grenoble, France
| | - K Benzerara
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Centre National de la Recherche Scientifique, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - S Bernard
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Centre National de la Recherche Scientifique, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - A S Burton
- NASA Johnson Space Center, Houston, TX 77058, USA
| | - E L Cardarelli
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - B Chide
- Planetary Exploration Team, Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - E Clavé
- Centre Lasers Intenses et Applications, Centre National de la Recherche Scientifique, Commissariat à l'Energie Atomique, Université de Bordeaux, 33400 Bordeaux, France
| | - E A Cloutis
- Centre for Terrestrial and Planetary Exploration, University of Winnipeg, Winnipeg, MB R3B 2E9, Canada
| | - B A Cohen
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - A D Czaja
- Department of Geology, University of Cincinnati, Cincinnati, OH 45221, USA
| | - V Debaille
- Laboratoire G-Time, Université Libre de Bruxelles, 1050 Brussels, Belgium
| | - E Dehouck
- Laboratoire de Géologie de Lyon: Terre, Université de Lyon, Université Claude Bernard Lyon1, Ecole Normale Supérieure de Lyon, Université Jean Monnet Saint Etienne, Centre National de la Recherche Scientifique, 69622 Villeurbanne, France
| | - A G Fairén
- Centro de Astrobiología, Consejo Superior de Investigaciones Científicas-Instituto Nacional de Técnica Aeroespacial, 28850 Madrid, Spain.,Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - D T Flannery
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4001, Australia
| | - S Z Fleron
- Department of Geosciences and Natural Resource Management, University of Copenhagen, 1350 Copenhagen, Denmark
| | - T Fouchet
- Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris, Centre National de la Recherche Scientifique, Sorbonne Université, Université Paris Diderot, 92195 Meudon, France
| | - J Frydenvang
- Globe Institute, University of Copenhagen, 1350 Copenhagen, Denmark
| | - B J Garczynski
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - E F Gibbons
- Department of Earth and Planetary Sciences, McGill University, Montreal, QC H3A 0E8, Canada
| | - E M Hausrath
- Department of Geoscience, University of Nevada, Las Vegas, Las Vegas, NV 89154, USA
| | - A G Hayes
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - J Henneke
- National Space Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - J L Jørgensen
- National Space Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - E M Kelly
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - J Lasue
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - S Le Mouélic
- Laboratoire de Planétologie et Géosciences, Centre National de la Recherche Scientifique, Nantes Université, Université Angers, 44000 Nantes, France
| | - J M Madariaga
- Department of Analytical Chemistry, University of the Basque Country, 48940 Leioa, Spain
| | - S Maurice
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - M Merusi
- Niels Bohr Institute, University of Copenhagen, 1350 Copenhagen, Denmark
| | - P-Y Meslin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - S M Milkovich
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | | | - R C Moeller
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J I Núñez
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
| | - A M Ollila
- Los Alamos National Laboratory, Los Alamos, NM 87545 USA
| | - G Paar
- Institute for Information and Communication Technologies, Joanneum Research, 8010 Graz, Austria
| | - D A Paige
- Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - D A K Pedersen
- National Space Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark
| | - P Pilleri
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - C Pilorget
- Institut d'Astrophysique Spatiale, Université Paris-Saclay, 91405 Orsay, France.,Institut Universitaire de France, Paris, France
| | - P C Pinet
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse 3 Paul Sabatier, Centre National de la Recherche Scientifique, Centre National d'Etude Spatiale, 31400 Toulouse, France
| | - J W Rice
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287, USA
| | - C Royer
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Centre National de la Recherche Scientifique, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - V Sautter
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Centre National de la Recherche Scientifique, Sorbonne Université, Muséum National d'Histoire Naturelle, 75005 Paris, France
| | - M Schulte
- Mars Exploration Program, Planetary Science Division, NASA Headquarters, Washington, DC 20546, USA
| | - M A Sephton
- Department of Earth Sciences and Engineering, Imperial College London, London SW7 2AZ, UK
| | - S K Sharma
- Hawai'i Institute of Geophysics and Planetology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - S F Sholes
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - N Spanovich
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M St Clair
- Million Concepts, Louisville, KY 40204, USA
| | - C D Tate
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - K Uckert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - S J VanBommel
- McDonnell Center for the Space Sciences and Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | | | - M-P Zorzano
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA
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3
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Liu Y, Tice MM, Schmidt ME, Treiman AH, Kizovski TV, Hurowitz JA, Allwood AC, Henneke J, Pedersen DAK, VanBommel SJ, Jones MWM, Knight AL, Orenstein BJ, Clark BC, Elam WT, Heirwegh CM, Barber T, Beegle LW, Benzerara K, Bernard S, Beyssac O, Bosak T, Brown AJ, Cardarelli EL, Catling DC, Christian JR, Cloutis EA, Cohen BA, Davidoff S, Fairén AG, Farley KA, Flannery DT, Galvin A, Grotzinger JP, Gupta S, Hall J, Herd CDK, Hickman-Lewis K, Hodyss RP, Horgan BHN, Johnson JR, Jørgensen JL, Kah LC, Maki JN, Mandon L, Mangold N, McCubbin FM, McLennan SM, Moore K, Nachon M, Nemere P, Nothdurft LD, Núñez JI, O'Neil L, Quantin-Nataf CM, Sautter V, Shuster DL, Siebach KL, Simon JI, Sinclair KP, Stack KM, Steele A, Tarnas JD, Tosca NJ, Uckert K, Udry A, Wade LA, Weiss BP, Wiens RC, Williford KH, Zorzano MP. An olivine cumulate outcrop on the floor of Jezero crater, Mars. Science 2022; 377:1513-1519. [PMID: 36007094 DOI: 10.1126/science.abo2756] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [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 geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigate the petrology of olivine and carbonate-bearing rocks of the Séítah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We find that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some Martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multi-stage cooling of a thick magma body.
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Affiliation(s)
- Y Liu
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - M M Tice
- Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA
| | - M E Schmidt
- Department of Earth Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - A H Treiman
- Lunar and Planetary Institute, Universities Space Research Association, Houston TX 77058, USA
| | - T V Kizovski
- Department of Earth Sciences, Brock University, St. Catharines, ON L2S 3A1, Canada
| | - J A Hurowitz
- Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - A C Allwood
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J Henneke
- Department of Space, Measurement and Instrumentation, Technical University of Denmark,, Lyngby, Denmark
| | - D A K Pedersen
- Department of Space, Measurement and Instrumentation, Technical University of Denmark,, Lyngby, Denmark
| | - S J VanBommel
- McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - M W M Jones
- Central Analytical Research Facility, and School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - A L Knight
- McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - B J Orenstein
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - B C Clark
- Space Science Institute, Boulder, CO 80301, USA
| | - W T Elam
- Applied Physics Lab and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98052, USA
| | - C M Heirwegh
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - T Barber
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - L W Beegle
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - K Benzerara
- Institut de Minéralogie, Physique des Matériaux et Cosmochimie, Centre National de la Recherche Scientifique (CNRS), Muséum National d'Histoire Naturelle, Sorbonne Université, Paris 75005, France
| | - S Bernard
- Institut de Minéralogie, Physique des Matériaux et Cosmochimie, Centre National de la Recherche Scientifique (CNRS), Muséum National d'Histoire Naturelle, Sorbonne Université, Paris 75005, France
| | - O Beyssac
- Institut de Minéralogie, Physique des Matériaux et Cosmochimie, Centre National de la Recherche Scientifique (CNRS), Muséum National d'Histoire Naturelle, Sorbonne Université, Paris 75005, France
| | - T Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - E L Cardarelli
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - D C Catling
- Department of Earth and Space Sciences, University of Washington, Seattle WA 98195, USA
| | - J R Christian
- McDonnell Center for the Space Sciences, Department of Earth and Planetary Sciences, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - E A Cloutis
- Department of Geography, University of Winnipeg, Winnipeg, Manitoba R3B 2E9, Canada
| | - B A Cohen
- NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
| | - S Davidoff
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - A G Fairén
- Centro de Astrobiología, Consejo Superior de Investigaciones Cientificas - Instituto Nacional de Tecnica Aeroespacial, Madrid 28850, Spain.,Dept. of Astronomy, Cornell University, Ithaca, NY 14853, USA
| | - K A Farley
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - D T Flannery
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - A Galvin
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - J P Grotzinger
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - S Gupta
- Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UK
| | - J Hall
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - C D K Herd
- Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Alberta T6G 2E3, Canada
| | - K Hickman-Lewis
- Department of Earth Sciences, The Natural History Museum, South Kensington, London, SW7 5BD, UK.,Dipartimento di Scienze Biologiche, Geologiche e Ambientali, Università di Bologna, via Zamboni 67, I-40126 Bologna, Italy
| | - R P Hodyss
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - B H N Horgan
- Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - J R Johnson
- Johns Hopkins University Applied Physics Laboratory Laurel, MD 20723, USA
| | - J L Jørgensen
- Department of Space, Measurement and Instrumentation, Technical University of Denmark,, Lyngby, Denmark
| | - L C Kah
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville TN 37996, USA
| | - J N Maki
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - L Mandon
- Laboratoire d'Etudes Spatiales et d'Instrumentation en Astrophysique, Observatoire de Paris-Université Paris Sciences et Lettres, CNRS, Sorbonne Université, Université de Paris Cité, Meudon 92190, France
| | - N Mangold
- Laboratoire Planetologie et Geosciences, Centre National de Recherches Scientifiques, Universite Nantes, Universite Angers, Unite Mixte de Recherche 6112, Nantes 44322, France
| | - F M McCubbin
- NASA Johnson Space Center, Houston, TX 77058, USA
| | - S M McLennan
- Department of Geosciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - K Moore
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - M Nachon
- Department of Geology and Geophysics, Texas A&M University, College Station, TX 77843, USA
| | - P Nemere
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - L D Nothdurft
- School of Earth and Atmospheric Sciences, Queensland University of Technology, Brisbane, QLD 4000, Australia
| | - J I Núñez
- Johns Hopkins University Applied Physics Laboratory Laurel, MD 20723, USA
| | - L O'Neil
- Applied Physics Lab and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98052, USA
| | - C M Quantin-Nataf
- Laboratoire de Geologie de Lyon-Terre Planetes Environnement, Univ Lyon, Universite Claude Bernard Lyon 1, Ecole Normale Superieure Lyon, Centre National de Recherches Scientifiques, 69622 Villeurbanne, France
| | - V Sautter
- Institut de Minéralogie, Physique des Matériaux et Cosmochimie, Centre National de la Recherche Scientifique (CNRS), Muséum National d'Histoire Naturelle, Sorbonne Université, Paris 75005, France
| | - D L Shuster
- Dept. Earth and Planetary Science, University of California, Berkeley, CA 94720, USA
| | - K L Siebach
- Department of Earth, Environmental, and Planetary Sciences, Rice University, Houston, TX 77005, USA
| | - J I Simon
- NASA Johnson Space Center, Houston, TX 77058, USA
| | - K P Sinclair
- Applied Physics Lab and Department of Earth and Space Sciences, University of Washington, Seattle, WA 98052, USA
| | - K M Stack
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - A Steele
- Earth and Planets Laboratory, Carnegie Institution for Science, Washington, DC 20015, USA
| | - J D Tarnas
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - N J Tosca
- Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, UK
| | - K Uckert
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - A Udry
- Department of Geosciences University of Nevada Las Vegas, Las Vegas, NV 89154, USA
| | - L A Wade
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA
| | - B P Weiss
- Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - R C Wiens
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - K H Williford
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.,Blue Marble Space Institute of Science, 600 1st Ave. Seattle, WA 98104, USA
| | - M-P Zorzano
- Centro de Astrobiología, Consejo Superior de Investigaciones Cientificas - Instituto Nacional de Tecnica Aeroespacial, Madrid 28850, Spain
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McGrath R, Cawthon PM, Clark BC, Fielding RA, Lang JJ, Tomkinson GR. Recommendations for Reducing Heterogeneity in Handgrip Strength Protocols. J Frailty Aging 2022; 11:143-150. [PMID: 35441190 DOI: 10.14283/jfa.2022.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Handgrip dynamometers are widely used to measure handgrip strength (HGS). HGS is a safe and easy to obtain measure of strength capacity, and a reliable assessment of muscle function. Although HGS provides robust prognostic value and utility, several protocol variants exist for HGS in clinical settings and translational research. This lack of methodological consistency could threaten the precision of HGS measurements and limit comparisons between the growing number of studies measuring HGS. Providing awareness of the protocol variants for HGS and making suggestions to reduce the implications of these variants will help to improve methodological consistency. Moreover, leveraging recent advancements in HGS equipment may enable us to use more sophisticated HGS dynamometer technologies to better assess muscle function. This Special Article will 1) highlight differences in HGS protocols and instrumentation, 2) provide recommendations to better specify HGS procedures and equipment, and 3) present future research directions for studies that measure HGS. We also provided a minimum reporting criteria framework to help future research studies avoid underreporting of HGS procedures.
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Affiliation(s)
- R McGrath
- Ryan McGrath, Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, NDSU Dept. 2620, PO Box 6050, Fargo, ND 58108, USA, Phone: 701-231-7474, Fax: 701-231-8872,
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Tavoian D, Russ DW, Law TD, Simon JE, Chase PJ, Guseman EH, Clark BC. Effects of Three Different Exercise Strategies for Optimizing Aerobic Capacity and Skeletal Muscle Performance in Older Adults: A Pilot Study. J Frailty Aging 2021; 10:357-360. [PMID: 34549251 PMCID: PMC8114968 DOI: 10.14283/jfa.2021.21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
This Brief Report describes a pilot study of the effect of 12 weeks of stationary bicycle high-intensity interval training, stationary bicycle moderate-intensity continuous training, and resistance training on cardiorespiratory, muscular, and physical function measures in insufficiently-active older adults (N=14; 66.4±3.9 years; 3 male, 11 female). After baseline testing, participants were randomly assigned to one of the exercise groups. High-intensity interval training and moderate-intensity continuous training had small-to-large effect sizes on cardiorespiratory/endurance and physical function measures, but very small effect sizes on muscular measures. Resistance training had small-to-large effect sizes on cardiorespiratory, muscular, and physical function measures. This pilot study should be interpreted cautiously, but findings suggest that resistance exercise may be the most effective of the three studied exercise strategies for older adults as it can induce beneficial adaptations across multiple domains. These effect sizes can be used to determine optimal sample sizes for future investigations.
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Affiliation(s)
- D Tavoian
- Dallin Tavoian, Ohio Musculoskeletal and Neurological Institute (OMNI), Ohio University, Athens, USA,
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Riwniak C, Simon JE, Wages NP, Clark LA, Manini TM, Russ DW, Clark BC. Comparison of a Multi-Component Physical Function Battery to Usual Walking Speed for Assessing Lower Extremity Function and Mobility Limitation in Older Adults. J Nutr Health Aging 2020; 24:906-913. [PMID: 33009544 PMCID: PMC9731178 DOI: 10.1007/s12603-020-1432-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [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] [Indexed: 12/29/2022]
Abstract
OBJECTIVES To compare a composite measure of physical function that comprises locomotor and non-locomotor tests (i.e., the Mobility Battery Assessment (MBA)) with traditional measures of mobility (4-m usual gait speed (UGS), six-minute walk (6MW) gait speed, and short physical performance battery (SPPB) score) for assessing lower extremity function and discriminating community dwelling older adults with and without mobility limitations. DESIGN Cross-sectional, observational study. SETTING Laboratory-based. PARTICIPANTS 89 community-dwelling older adults (74.9±6.7). MEASUREMENTS Using principal component analysis we derived an MBA score for 89 community-dwelling older adults, and quantified 4-m UGS, 6MW gait speed, and SPPB score. The MBA score was based on five lab-based tests. We also quantified self-reported lower extremity function/mobility using the Neuro-QOL Lower Extremity Function-Mobility instrument. Based on this data a continuous score was derived and subjects were classified as "mobility limited" or "non-mobility limited". Correlations between the mobility measures and the Neuro-QOL score were calculated, and ROC curves were constructed to determine the AUC for the mobility measures ability to predict mobility limitations. RESULTS The MBA had the largest AUC (0.92) for discriminating mobility limitations and exhibited the strongest correlation (0.73) with the Neuro-QOL Lower Extremity Function-Mobility Scale. The worst performing predictors were the 4-meter UGS and stair climb power both with an AUC of 0.8 for discriminating mobility limitations, and a low correlation with Neuro-QOL Lower Extremity Function Scale of 0.39 and 0.46, respectively. CONCLUSION The MBA score moderately improves the magnitude of correlation and discrimination of mobility limitation in older adults than singular, standard tests of mobility.
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Affiliation(s)
- C Riwniak
- Brian C. Clark, Ph.D., Ohio Musculoskeletal and Neurological Institute, Ohio University, 250 Irvine Hall, Athens, OH 45701, 740-593-2354, ,
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Conrad RJ, Clark BC, Russell DM, Mayo JS, Balla FM, Lim RB, Kellicut DC, Yheulon CG. Publication Patterns and the Impact of Self-Citation among General Surgery Residency Programs. Am Surg 2020; 86:e10-e13. [PMID: 32077424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
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8
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Conrad RJ, Clark BC, Russell DM, Mayo JS, Balla FM, Lim RB, Kellicut DC, Yheulon CG. Publication Patterns and the Impact of Self-Citation among General Surgery Residency Programs. Am Surg 2020. [DOI: 10.1177/000313482008600107] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Robert J. Conrad
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
| | - Benjamin C. Clark
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
| | - Dylan M. Russell
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
| | - John S. Mayo
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
| | - Fadi M. Balla
- Department of Surgery Kaiser Westside Medical Center Hillsboro, Oregon
| | - Robert B. Lim
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
| | - Dwight C. Kellicut
- Department of General Surgery Tripler Army Medical Center Honolulu, Hawaii
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9
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McGrath R, Erlandson KM, Vincent BM, Hackney KJ, Herrmann SD, Clark BC. Decreased Handgrip Strength is Associated With Impairments in Each Autonomous Living Task for Aging Adults in the United States. J Frailty Aging 2019; 8:141-145. [PMID: 31237315 DOI: 10.14283/jfa.2018.47] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVES The primary purpose of this study was to determine the time-varying associations between decreased handgrip strength (HGS) and individual instrumental activities of daily living (IADL) impairments for a nationally-representative sample of aging adults in the United States. DESIGN Longitudinal-Panel. SETTING Detailed interviews were completed in person and core interviews were typically completed over the telephone. PARTICIPANTS A total of 15,336 participants aged at least 50 years who participated in the 2006 wave of the Health and Retirement Study were followed biennially for 8-years. MEASUREMENTS A hand-held dynamometer assessed HGS and performance in IADLs were self-reported. RESULTS Every 5-kilogram decrease in HGS was associated with an increased odds ratio for the following IADL impairments: 1.11 (95% confidence interval (CI): 1.09, 1.13) for using a map, 1.10 (CI: 1.07, 1.12) for grocery shopping, 1.09 (CI: 1.05, 1.14) for taking medications, 1.07 (CI: 1.05, 1.09) for preparing hot meals, 1.06 (CI: 1.04, 1.08) for managing money, and 1.05 (CI: 1.02, 1.09) for using a telephone. CONCLUSIONS Decreased HGS was associated with each IADL impairment, and slightly different associations were observed in individual IADL tasks for aging adults in the United States. Our findings suggest that decreased HGS, which is reflective of reduced function of the neuromuscular system, is associated with diminished performance in autonomous living tasks during aging. Losses in HGS may lead to the development of an IADL impairment. Therefore, health-care providers working with aging adults should utilize measures of HGS as a screening tool for identifying future deficits in neuromuscular functioning. Interventions designed to preserve IADLs in aging adults should also include measures of HGS for detecting early changes in IADL capacity, and intervening at the onset of HGS declines may help aging adults retain their ability to live autonomously.
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Affiliation(s)
- R McGrath
- Ryan McGrath, PhD, Department of Health, Nutrition, and Exercise Sciences, North Dakota State University, NDSU Dept. 2620, PO Box 6050, Fargo, ND 58108-6050,
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Abstract
Sarcopenia was originally conceptualized as the age-related loss of skeletal muscle mass. Over the ensuing decades, the conceptual definition of sarcopenia has changed to represent a condition in older adults that is characterized by declining muscle mass and function, with "function" most commonly conceived as muscle weakness and/or impaired physical performance (e.g., slow gait speed). Findings over the past 15-years, however, have demonstrated that changes in grip and leg extensor strength are not primarily due to muscle atrophy per se, and that to a large extent, are reflective of declines in the integrity of the nervous system. This article briefly summarizes findings relating to the complex neuromuscular mechanisms that contribute to reductions in muscle function associated with advancing age, and the implications of these findings on the development of effective therapies.
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Affiliation(s)
- B C Clark
- Brian C. Clark, Ph.D. Ohio University, Ohio Musculoskeletal and Neurological Institute (OMNI), 250 Irvine Hall, Athens, OH 45701, USA, Phone: 740.593.2354,
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Consitt LA, Clark BC. The Vicious Cycle of Myostatin Signaling in Sarcopenic Obesity: Myostatin Role in Skeletal Muscle Growth, Insulin Signaling and Implications for Clinical Trials. J Frailty Aging 2018; 7:21-27. [PMID: 29412438 DOI: 10.14283/jfa.2017.33] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The age-related loss of skeletal muscle (sarcopenia) is a major health concern as it is associated with physical disability, metabolic impairments, and increased mortality. The coexistence of sarcopenia with obesity, termed 'sarcopenic obesity', contributes to skeletal muscle insulin resistance and the development of type 2 diabetes, a disease prevalent with advancing age. Despite this knowledge, the mechanisms contributing to sarcopenic obesity remain poorly understood, preventing the development of targeted therapeutics. This article will discuss the clinical and physiological consequences of sarcopenic obesity and propose myostatin as a potential candidate contributing to this condition. A special emphasis will be placed on examining the role of myostatin signaling in impairing both skeletal muscle growth and insulin signaling. In addition, the role of myostatin in regulating muscle-to fat cross talk, further exacerbating metabolic dysfunction in the elderly, will be highlighted. Lastly, we discuss how this knowledge has implications for the design of myostatin-inhibitor clinical trials.
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Affiliation(s)
- L A Consitt
- Leslie Consitt, PhD, Department of Biomedical Sciences, 228 Irvine Hall, Ohio University, Athens, Ohio, 45701, , Phone: 740-593-2404, Fax: 740-597-2778
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12
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Dworkin JP, Adelman LA, Ajluni T, Andronikov AV, Aponte JC, Bartels AE, Beshore E, Bierhaus EB, Brucato JR, Bryan BH, Burton AS, Callahan MP, Castro-Wallace SL, Clark BC, Clemett SJ, Connolly HC, Cutlip WE, Daly SM, Elliott VE, Elsila JE, Enos HL, Everett DF, Franchi IA, Glavin DP, Graham HV, Hendershot JE, Harris JW, Hill SL, Hildebrand AR, Jayne GO, Jenkens RW, Johnson KS, Kirsch JS, Lauretta DS, Lewis AS, Loiacono JJ, Lorentson CC, Marshall JR, Martin MG, Matthias LL, McLain HL, Messenger SR, Mink RG, Moore JL, Nakamura-Messenger K, Nuth JA, Owens CV, Parish CL, Perkins BD, Pryzby MS, Reigle CA, Righter K, Rizk B, Russell JF, Sandford SA, Schepis JP, Songer J, Sovinski MF, Stahl SE, Thomas-Keprta K, Vellinga JM, Walker MS. OSIRIS-REx Contamination Control Strategy and Implementation. Space Sci Rev 2018; 214:19. [PMID: 30713357 PMCID: PMC6350808 DOI: 10.1007/s11214-017-0439-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
OSIRIS-REx will return pristine samples of carbonaceous asteroid Bennu. This article describes how pristine was defined based on expectations of Bennu and on a realistic understanding of what is achievable with a constrained schedule and budget, and how that definition flowed to requirements and implementation. To return a pristine sample, the OSIRIS-REx spacecraft sampling hardware was maintained at level 100 A/2 and <180 ng/cm2 of amino acids and hydrazine on the sampler head through precision cleaning, control of materials, and vigilance. Contamination is further characterized via witness material exposed to the spacecraft assembly and testing environment as well as in space. This characterization provided knowledge of the expected background and will be used in conjunction with archived spacecraft components for comparison with the samples when they are delivered to Earth for analysis. Most of all, the cleanliness of the OSIRIS-REx spacecraft was achieved through communication among scientists, engineers, managers, and technicians.
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Affiliation(s)
- J P Dworkin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - L A Adelman
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Arctic Slope Research Corporation, Beltsville, MD USA
| | - T Ajluni
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Arctic Slope Research Corporation, Beltsville, MD USA
| | | | - J C Aponte
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Catholic University of America, Washington, DC, USA
| | - A E Bartels
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - E Beshore
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - E B Bierhaus
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - J R Brucato
- INAF Astrophysical Observatory of Arcetri, Florence, Italy
| | - B H Bryan
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - A S Burton
- NASA Johnson Space Center, Houston, TX, USA
| | | | | | - B C Clark
- Space Science Institute, Boulder, CO, USA
| | - S J Clemett
- NASA Johnson Space Center, Houston, TX, USA
- Jacobs Technology, Tullahoma, TN, USA
| | | | - W E Cutlip
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - S M Daly
- NASA Kennedy Space Center, Titusville, FL, USA
| | - V E Elliott
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J E Elsila
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - H L Enos
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - D F Everett
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - D P Glavin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - H V Graham
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- University of Maryland, College Park, MD, USA
| | - J E Hendershot
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Ball Aerospace, Boulder, CO, USA
| | - J W Harris
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - S L Hill
- Jacobs Technology, Tullahoma, TN, USA
- NASA Kennedy Space Center, Titusville, FL, USA
| | | | - G O Jayne
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Arctic Slope Research Corporation, Beltsville, MD USA
| | - R W Jenkens
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - K S Johnson
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - J S Kirsch
- Jacobs Technology, Tullahoma, TN, USA
- NASA Kennedy Space Center, Titusville, FL, USA
| | - D S Lauretta
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - A S Lewis
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J J Loiacono
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C C Lorentson
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - M G Martin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Catholic University of America, Washington, DC, USA
| | - L L Matthias
- NASA Kennedy Space Center, Titusville, FL, USA
- Analex, Titusville, FL, USA
| | - H L McLain
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Catholic University of America, Washington, DC, USA
| | | | - R G Mink
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J L Moore
- Lockheed Martin Space Systems, Littleton, CO, USA
| | | | - J A Nuth
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C V Owens
- NASA Kennedy Space Center, Titusville, FL, USA
| | - C L Parish
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - B D Perkins
- NASA Kennedy Space Center, Titusville, FL, USA
| | - M S Pryzby
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- ATA Aerospace, Albuquerque, NM, USA
| | - C A Reigle
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - K Righter
- NASA Johnson Space Center, Houston, TX, USA
| | - B Rizk
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - J F Russell
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - S A Sandford
- NASA Ames Research Center, Moffett Field, CA, USA
| | - J P Schepis
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J Songer
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - M F Sovinski
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - S E Stahl
- NASA Johnson Space Center, Houston, TX, USA
- JES Tech., Houston, TX, USA
| | - K Thomas-Keprta
- NASA Johnson Space Center, Houston, TX, USA
- Jacobs Technology, Tullahoma, TN, USA
| | - J M Vellinga
- Lockheed Martin Space Systems, Littleton, CO, USA
| | - M S Walker
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
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Dent E, Morley JE, Cruz-Jentoft AJ, Arai H, Kritchevsky SB, Guralnik J, Bauer JM, Pahor M, Clark BC, Cesari M, Ruiz J, Sieber CC, Aubertin-Leheudre M, Waters DL, Visvanathan R, Landi F, Villareal DT, Fielding R, Won CW, Theou O, Martin FC, Dong B, Woo J, Flicker L, Ferrucci L, Merchant RA, Cao L, Cederholm T, Ribeiro SML, Rodríguez-Mañas L, Anker SD, Lundy J, Gutiérrez Robledo LM, Bautmans I, Aprahamian I, Schols JMGA, Izquierdo M, Vellas B. International Clinical Practice Guidelines for Sarcopenia (ICFSR): Screening, Diagnosis and Management. J Nutr Health Aging 2018; 22:1148-1161. [PMID: 30498820 DOI: 10.1007/s12603-018-1139-9] [Citation(s) in RCA: 447] [Impact Index Per Article: 74.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Sarcopenia, defined as an age-associated loss of skeletal muscle function and muscle mass, occurs in approximately 6 - 22 % of older adults. This paper presents evidence-based clinical practice guidelines for screening, diagnosis and management of sarcopenia from the task force of the International Conference on Sarcopenia and Frailty Research (ICSFR). METHODS To develop the guidelines, we drew upon the best available evidence from two systematic reviews paired with consensus statements by international working groups on sarcopenia. Eight topics were selected for the recommendations: (i) defining sarcopenia; (ii) screening and diagnosis; (iii) physical activity prescription; (iv) protein supplementation; (v) vitamin D supplementation; (vi) anabolic hormone prescription; (vii) medications under development; and (viii) research. The ICSFR task force evaluated the evidence behind each topic including the quality of evidence, the benefit-harm balance of treatment, patient preferences/values, and cost-effectiveness. Recommendations were graded as either strong or conditional (weak) as per the GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Consensus was achieved via one face-to-face workshop and a modified Delphi process. RECOMMENDATIONS We make a conditional recommendation for the use of an internationally accepted measurement tool for the diagnosis of sarcopenia including the EWGSOP and FNIH definitions, and advocate for rapid screening using gait speed or the SARC-F. To treat sarcopenia, we strongly recommend the prescription of resistance-based physical activity, and conditionally recommend protein supplementation/a protein-rich diet. No recommendation is given for Vitamin D supplementation or for anabolic hormone prescription. There is a lack of robust evidence to assess the strength of other treatment options.
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Affiliation(s)
- E Dent
- Dr. Elsa Dent, , Torrens University Australia, Wakefield Street, Adelaide, SA, Australia
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Summons RE, Sessions AL, Allwood AC, Barton HA, Beaty DW, Blakkolb B, Canham J, Clark BC, Dworkin JP, Lin Y, Mathies R, Milkovich SM, Steele A. Planning considerations related to the organic contamination of Martian samples and implications for the Mars 2020 Rover. Astrobiology 2014; 14:969-1027. [PMID: 25495496 DOI: 10.1089/ast.2014.1244] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- R E Summons
- 1 Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology , Cambridge, Massachusetts
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McLennan SM, Anderson RB, Bell JF, Bridges JC, Calef F, Campbell JL, Clark BC, Clegg S, Conrad P, Cousin A, Des Marais DJ, Dromart G, Dyar MD, Edgar LA, Ehlmann BL, Fabre C, Forni O, Gasnault O, Gellert R, Gordon S, Grant JA, Grotzinger JP, Gupta S, Herkenhoff KE, Hurowitz JA, King PL, Le Mouélic S, Leshin LA, Léveillé R, Lewis KW, Mangold N, Maurice S, Ming DW, Morris RV, Nachon M, Newsom HE, Ollila AM, Perrett GM, Rice MS, Schmidt ME, Schwenzer SP, Stack K, Stolper EM, Sumner DY, Treiman AH, VanBommel S, Vaniman DT, Vasavada A, Wiens RC, Yingst RA. Elemental geochemistry of sedimentary rocks at Yellowknife Bay, Gale crater, Mars. Science 2013; 343:1244734. [PMID: 24324274 DOI: 10.1126/science.1244734] [Citation(s) in RCA: 214] [Impact Index Per Article: 19.5] [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
Sedimentary rocks examined by the Curiosity rover at Yellowknife Bay, Mars, were derived from sources that evolved from an approximately average martian crustal composition to one influenced by alkaline basalts. No evidence of chemical weathering is preserved, indicating arid, possibly cold, paleoclimates and rapid erosion and deposition. The absence of predicted geochemical variations indicates that magnetite and phyllosilicates formed by diagenesis under low-temperature, circumneutral pH, rock-dominated aqueous conditions. Analyses of diagenetic features (including concretions, raised ridges, and fractures) at high spatial resolution indicate that they are composed of iron- and halogen-rich components, magnesium-iron-chlorine-rich components, and hydrated calcium sulfates, respectively. Composition of a cross-cutting dike-like feature is consistent with sedimentary intrusion. The geochemistry of these sedimentary rocks provides further evidence for diverse depositional and diagenetic sedimentary environments during the early history of Mars.
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Affiliation(s)
- S M McLennan
- Department of Geosciences, State University of New York, Stony Brook, NY 11794, USA
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Meslin PY, Gasnault O, Forni O, Schröder S, Cousin A, Berger G, Clegg SM, Lasue J, Maurice S, Sautter V, Le Mouélic S, Wiens RC, Fabre C, Goetz W, Bish D, Mangold N, Ehlmann B, Lanza N, Harri AM, Anderson R, Rampe E, McConnochie TH, Pinet P, Blaney D, Léveillé R, Archer D, Barraclough B, Bender S, Blake D, Blank JG, Bridges N, Clark BC, DeFlores L, Delapp D, Dromart G, Dyar MD, Fisk M, Gondet B, Grotzinger J, Herkenhoff K, Johnson J, Lacour JL, Langevin Y, Leshin L, Lewin E, Madsen MB, Melikechi N, Mezzacappa A, Mischna MA, Moores JE, Newsom H, Ollila A, Perez R, Renno N, Sirven JB, Tokar R, de la Torre M, d'Uston L, Vaniman D, Yingst A. Soil diversity and hydration as observed by ChemCam at Gale crater, Mars. Science 2013; 341:1238670. [PMID: 24072924 DOI: 10.1126/science.1238670] [Citation(s) in RCA: 190] [Impact Index Per Article: 17.3] [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 ChemCam instrument, which provides insight into martian soil chemistry at the submillimeter scale, identified two principal soil types along the Curiosity rover traverse: a fine-grained mafic type and a locally derived, coarse-grained felsic type. The mafic soil component is representative of widespread martian soils and is similar in composition to the martian dust. It possesses a ubiquitous hydrogen signature in ChemCam spectra, corresponding to the hydration of the amorphous phases found in the soil by the CheMin instrument. This hydration likely accounts for an important fraction of the global hydration of the surface seen by previous orbital measurements. ChemCam analyses did not reveal any significant exchange of water vapor between the regolith and the atmosphere. These observations provide constraints on the nature of the amorphous phases and their hydration.
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Affiliation(s)
- P-Y Meslin
- Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse, France.
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Manini TM, Clark BC. WHAT WE HAVE LEARNED FROM EXERCISE AND LIFESTYLE TRIALS TO ALLEVIATE MOBILITY IMPAIRMENT IN OLDER ADULTS. J Frailty Aging 2013; 2:57-59. [PMID: 26568947 PMCID: PMC4643951] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Enhancement of cardiovascular and muscular fitness through exercise and lifestyle interventions is critical to in alleviating mobility impairment in older adults. In this review article, we discuss the current knowledge-base surrounding mobility improvements in seniors following behavioral interventions that use lifestyle modifications involving physical activity and dietary interventions.
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Affiliation(s)
- T M Manini
- Institute on Aging & the Department of Aging and Geriatric Research, University of Florida, Gainesville, FL USA
| | - B C Clark
- Ohio Musculoskeletal and Neurological Institute (OMNI) & the Department of Biomedical Sciences, Ohio University, Athens, OH USA
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Manini TM, Vincent KR, Leeuwenburgh CL, Lees HA, Kavazis AN, Borst SE, Clark BC. Myogenic and proteolytic mRNA expression following blood flow restricted exercise. Acta Physiol (Oxf) 2011; 201:255-63. [PMID: 20653608 DOI: 10.1111/j.1748-1716.2010.02172.x] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.9] [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: 11/27/2022]
Abstract
AIM Resistance exercise performed at low loads (20-30% of maximal strength) with blood flow restriction (BFR) acutely increases protein synthesis and induces hypertrophy when performed chronically. We investigated myogenic and proteolytic mRNA expression 8 h following an acute bout of knee extension exercise. METHODS Fifteen subjects (22.8 ± 3.7 years, eight men and seven women) were randomized to two exercise conditions: BFR or control exercise. All participants performed four sets of exercise (30, 15, 15 and 15 repetitions) at 20% of maximal strength. Persons in the BFR group had a cuff placed on the upper thigh inflated to 1.5 times brachial systolic blood pressure (cuff pressure range: 135-186 mmHg). Muscle biopsies from the vastus lateralis were excised 24 h before and 8 h following the exercise. RESULTS RT-PCR analysis demonstrated no change in myogenic gene expression (insulin-like growth factor-1, MyoD, myogenin, myostatin - a negative regulator) with either exercise condition (P > 0.123). However, BFR exercise downregulated mRNA expression in transcripts associated with proteolytic pathways (FOXO3A, Atrogin-1 and MuRF-1) with no change in the control exercise condition. Specifically, median mRNA expression of FOXO3A decreased by 1.92-fold (P = 0.01), Atrogin-1 by 2.10-fold (P = 0.01) and MuRF-1 by 2.44-fold (P = 0.01). CONCLUSION These data are consistent with the downregulation of proteolytic transcripts observed following high-load resistance exercise. In summary, myogenic genes are unchanged and proteolytic genes associated with muscle remodelling are reduced 8 h following low-load BFR exercise.
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Affiliation(s)
- T M Manini
- Department of Aging and Geriatric Research, University of Florida, Gainesville, FL 32611-0107, USA.
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Clark BC, Manini TM, Hoffman RL, Williams PS, Guiler MK, Knutson MJ, McGlynn ML, Kushnick MR. Relative safety of 4 weeks of blood flow-restricted resistance exercise in young, healthy adults. Scand J Med Sci Sports 2010; 21:653-62. [PMID: 21917016 DOI: 10.1111/j.1600-0838.2010.01100.x] [Citation(s) in RCA: 132] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
This study evaluated the effect of 4 weeks of low-load resistance exercise with blood flow restriction (BFRE) on increasing strength in comparison with high-load resistance exercise (HLE), and assessed changes in blood, vascular and neural function. Healthy adults performed leg extension BFRE or HLE 3 days/week at 30% and 80% of strength, respectively. During BFRE, a cuff on the upper leg was inflated to 30% above systolic blood pressure. Strength, pulse-wave velocity (PWV), ankle-brachial index (ABI), prothrombin time (PT) and nerve conduction (NC) were measured before and after training. Markers of coagulation (fibrinogen and D-dimer), fibrinolysis [tissue plasminogen activator (tPA)] and inflammation [high sensitivity C-reactive protein (hsCRP)] were measured in response to the first and last exercise bouts. Strength increased 8% with BFRE and 13% with HLE (P<0.01). No changes in PWV, ABI, PT or NC were observed following training for either group (P>0.05). tPA antigen increased 30-40% immediately following acute bouts of BFRE and HLE (P=0.01). No changes were observed in fibrinogen, D-dimer or hsCRP (P>0.05). These findings indicate that both protocols increase the strength without altering nerve or vascular function, and that a single bout of both protocols increases fibrinolytic activity without altering selected markers of coagulation or inflammation in healthy individuals.
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Affiliation(s)
- B C Clark
- Department of Biomedical Sciences, Institute for Neuromusculoskeletal Research, Ohio University, Athens, Ohio 45701, USA.
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Smith PH, Tamppari LK, Arvidson RE, Bass D, Blaney D, Boynton WV, Carswell A, Catling DC, Clark BC, Duck T, Dejong E, Fisher D, Goetz W, Gunnlaugsson HP, Hecht MH, Hipkin V, Hoffman J, Hviid SF, Keller HU, Kounaves SP, Lange CF, Lemmon MT, Madsen MB, Markiewicz WJ, Marshall J, McKay CP, Mellon MT, Ming DW, Morris RV, Pike WT, Renno N, Staufer U, Stoker C, Taylor P, Whiteway JA, Zent AP. H2O at the Phoenix landing site. Science 2009; 325:58-61. [PMID: 19574383 DOI: 10.1126/science.1172339] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [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 Phoenix mission investigated patterned ground and weather in the northern arctic region of Mars for 5 months starting 25 May 2008 (solar longitude between 76.5 degrees and 148 degrees ). A shallow ice table was uncovered by the robotic arm in the center and edge of a nearby polygon at depths of 5 to 18 centimeters. In late summer, snowfall and frost blanketed the surface at night; H(2)O ice and vapor constantly interacted with the soil. The soil was alkaline (pH = 7.7) and contained CaCO(3), aqueous minerals, and salts up to several weight percent in the indurated surface soil. Their formation likely required the presence of water.
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Affiliation(s)
- P H Smith
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA.
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Squyres SW, Aharonson O, Clark BC, Cohen BA, Crumpler L, de Souza PA, Farrand WH, Gellert R, Grant J, Grotzinger JP, Haldemann AFC, Johnson JR, Klingelhöfer G, Lewis KW, Li R, McCoy T, McEwen AS, McSween HY, Ming DW, Moore JM, Morris RV, Parker TJ, Rice JW, Ruff S, Schmidt M, Schröder C, Soderblom LA, Yen A. Pyroclastic activity at Home Plate in Gusev Crater, Mars. Science 2007; 316:738-42. [PMID: 17478719 DOI: 10.1126/science.1139045] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [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
Home Plate is a layered plateau in Gusev crater on Mars. It is composed of clastic rocks of moderately altered alkali basalt composition, enriched in some highly volatile elements. A coarsegrained lower unit lies under a finer-grained upper unit. Textural observations indicate that the lower strata were emplaced in an explosive event, and geochemical considerations favor an explosive volcanic origin over an impact origin. The lower unit likely represents accumulation of pyroclastic materials, whereas the upper unit may represent eolian reworking of the same pyroclastic materials.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Space Sciences Building, Cornell University, Ithaca, NY 14853, USA
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Brownlee D, Tsou P, Aléon J, Alexander CMO, Araki T, Bajt S, Baratta GA, Bastien R, Bland P, Bleuet P, Borg J, Bradley JP, Brearley A, Brenker F, Brennan S, Bridges JC, Browning ND, Brucato JR, Bullock E, Burchell MJ, Busemann H, Butterworth A, Chaussidon M, Cheuvront A, Chi M, Cintala MJ, Clark BC, Clemett SJ, Cody G, Colangeli L, Cooper G, Cordier P, Daghlian C, Dai Z, D'Hendecourt L, Djouadi Z, Dominguez G, Duxbury T, Dworkin JP, Ebel DS, Economou TE, Fakra S, Fairey SAJ, Fallon S, Ferrini G, Ferroir T, Fleckenstein H, Floss C, Flynn G, Franchi IA, Fries M, Gainsforth Z, Gallien JP, Genge M, Gilles MK, Gillet P, Gilmour J, Glavin DP, Gounelle M, Grady MM, Graham GA, Grant PG, Green SF, Grossemy F, Grossman L, Grossman JN, Guan Y, Hagiya K, Harvey R, Heck P, Herzog GF, Hoppe P, Hörz F, Huth J, Hutcheon ID, Ignatyev K, Ishii H, Ito M, Jacob D, Jacobsen C, Jacobsen S, Jones S, Joswiak D, Jurewicz A, Kearsley AT, Keller LP, Khodja H, Kilcoyne ALD, Kissel J, Krot A, Langenhorst F, Lanzirotti A, Le L, Leshin LA, Leitner J, Lemelle L, Leroux H, Liu MC, Luening K, Lyon I, Macpherson G, Marcus MA, Marhas K, Marty B, Matrajt G, McKeegan K, Meibom A, Mennella V, Messenger K, Messenger S, Mikouchi T, Mostefaoui S, Nakamura T, Nakano T, Newville M, Nittler LR, Ohnishi I, Ohsumi K, Okudaira K, Papanastassiou DA, Palma R, Palumbo ME, Pepin RO, Perkins D, Perronnet M, Pianetta P, Rao W, Rietmeijer FJM, Robert F, Rost D, Rotundi A, Ryan R, Sandford SA, Schwandt CS, See TH, Schlutter D, Sheffield-Parker J, Simionovici A, Simon S, Sitnitsky I, Snead CJ, Spencer MK, Stadermann FJ, Steele A, Stephan T, Stroud R, Susini J, Sutton SR, Suzuki Y, Taheri M, Taylor S, Teslich N, Tomeoka K, Tomioka N, Toppani A, Trigo-Rodríguez JM, Troadec D, Tsuchiyama A, Tuzzolino AJ, Tyliszczak T, Uesugi K, Velbel M, Vellenga J, Vicenzi E, Vincze L, Warren J, Weber I, Weisberg M, Westphal AJ, Wirick S, Wooden D, Wopenka B, Wozniakiewicz P, Wright I, Yabuta H, Yano H, Young ED, Zare RN, Zega T, Ziegler K, Zimmerman L, Zinner E, Zolensky M. Comet 81P/Wild 2 Under a Microscope. Science 2006; 314:1711-6. [PMID: 17170289 DOI: 10.1126/science.1135840] [Citation(s) in RCA: 740] [Impact Index Per Article: 41.1] [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
The Stardust spacecraft collected thousands of particles from comet 81P/Wild 2 and returned them to Earth for laboratory study. The preliminary examination of these samples shows that the nonvolatile portion of the comet is an unequilibrated assortment of materials that have both presolar and solar system origin. The comet contains an abundance of silicate grains that are much larger than predictions of interstellar grain models, and many of these are high-temperature minerals that appear to have formed in the inner regions of the solar nebula. Their presence in a comet proves that the formation of the solar system included mixing on the grandest scales.
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Affiliation(s)
- Don Brownlee
- Department of Astronomy, University of Washington, Seattle, WA 98195, USA.
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Squyres SW, Aharonson O, Arvidson RE, Bell JF, Christensen PR, Clark BC, Crisp JA, Farrand W, Glotch T, Golombek MP, Grant J, Grotzinger J, Herkenhoff KE, Johnson JR, Jolliff BL, Knoll AH, McLennan SM, McSween HY, Moore JM, Rice JW, Tosca N. Planetary science: bedrock formation at Meridiani Planum. Nature 2006; 443:E1-2; discussion E2. [PMID: 16957684 DOI: 10.1038/nature05212] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Mars Exploration Rover Opportunity discovered sulphate-rich sedimentary rocks at Meridiani Planum on Mars, which are interpreted by McCollom and Hynek as altered volcanic rocks. However, their conclusions are derived from an incorrect representation of our depositional model, which is upheld by more recent Rover data. We contend that all the available data still support an aeolian and aqueous sedimentary origin for Meridiani bedrock.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Cornell University, Ithaca, New York 14853, USA.
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Squyres SW, Knoll AH, Arvidson RE, Clark BC, Grotzinger JP, Jolliff BL, McLennan SM, Tosca N, Bell JF, Calvin WM, Farrand WH, Glotch TD, Golombek MP, Herkenhoff KE, Johnson JR, Klingelhöfer G, McSween HY, Yen AS. Two Years at Meridiani Planum: Results from the Opportunity Rover. Science 2006; 313:1403-7. [PMID: 16959999 DOI: 10.1126/science.1130890] [Citation(s) in RCA: 42] [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: 11/02/2022]
Abstract
The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling approximately 8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict "hopper crystals" that might reflect the formation of halite, thick weathering rinds on rock surfaces, resistant fracture fills, and networks of polygonal fractures likely caused by dehydration of sulfate salts. Chemical variations with depth show that the siliciclastic fraction of outcrop rock has undergone substantial chemical alteration from a precursor basaltic composition. Observations from microscopic to orbital scales indicate that ancient Meridiani once had abundant acidic groundwater, arid and oxidizing surface conditions, and occasional liquid flow on the surface.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Space Sciences Building, Cornell University, Ithaca, NY 14853, USA
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Lisse CM, Vancleve J, Adams AC, A'hearn MF, Fernández YR, Farnham TL, Armus L, Grillmair CJ, Ingalls J, Belton MJS, Groussin O, McFadden LA, Meech KJ, Schultz PH, Clark BC, Feaga LM, Sunshine JM. Spitzer Spectral Observations of the Deep Impact Ejecta. Science 2006; 313:635-40. [PMID: 16840662 DOI: 10.1126/science.1124694] [Citation(s) in RCA: 260] [Impact Index Per Article: 14.4] [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
Spitzer Space Telescope imaging spectrometer observations of comet 9P/Tempel 1 during the Deep Impact encounter returned detailed, highly structured, 5- to 35-micrometer spectra of the ejecta. Emission signatures due to amorphous and crystalline silicates, amorphous carbon, carbonates, phyllosilicates, polycyclic aromatic hydrocarbons, water gas and ice, and sulfides were found. Good agreement is seen between the ejecta spectra and the material emitted from comet C/1995 O1 (Hale-Bopp) and the circumstellar material around the young stellar object HD100546. The atomic abundance of the observed material is consistent with solar and C1 chondritic abundances, and the dust-to-gas ratio was determined to be greater than or equal to 1.3. The presence of the observed mix of materials requires efficient methods of annealing amorphous silicates and mixing of high- and low-temperature phases over large distances in the early protosolar nebula.
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Affiliation(s)
- C M Lisse
- Planetary Exploration Group, Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA
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Squyres SW, Arvidson RE, Bell JF, Brückner J, Cabrol NA, Calvin W, Carr MH, Christensen PR, Clark BC, Crumpler L, Marais DJD, d'Uston C, Economou T, Farmer J, Farrand W, Folkner W, Golombek M, Gorevan S, Grant JA, Greeley R, Grotzinger J, Haskin L, Herkenhoff KE, Hviid S, Johnson J, Klingelhöfer G, Knoll AH, Landis G, Lemmon M, Li R, Madsen MB, Malin MC, McLennan SM, McSween HY, Ming DW, Moersch J, Morris RV, Parker T, Rice JW, Richter L, Rieder R, Sims M, Smith M, Smith P, Soderblom LA, Sullivan R, Wänke H, Wdowiak T, Wolff M, Yen A. The Opportunity Rover's Athena science investigation at Meridiani Planum, Mars. Science 2004; 306:1698-703. [PMID: 15576602 DOI: 10.1126/science.1106171] [Citation(s) in RCA: 130] [Impact Index Per Article: 6.5] [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
The Mars Exploration Rover Opportunity has investigated the landing site in Eagle crater and the nearby plains within Meridiani Planum. The soils consist of fine-grained basaltic sand and a surface lag of hematite-rich spherules, spherule fragments, and other granules. Wind ripples are common. Underlying the thin soil layer, and exposed within small impact craters and troughs, are flat-lying sedimentary rocks. These rocks are finely laminated, are rich in sulfur, and contain abundant sulfate salts. Small-scale cross-lamination in some locations provides evidence for deposition in flowing liquid water. We interpret the rocks to be a mixture of chemical and siliciclastic sediments formed by episodic inundation by shallow surface water, followed by evaporation, exposure, and desiccation. Hematite-rich spherules are embedded in the rock and eroding from them. We interpret these spherules to be concretions formed by postdepositional diagenesis, again involving liquid water.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Space Sciences Building, Cornell University, Ithaca, NY 14853, USA.
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Rieder R, Gellert R, Anderson RC, Brückner J, Clark BC, Dreibus G, Economou T, Klingelhöfer G, Lugmair GW, Ming DW, Squyres SW, d'Uston C, Wänke H, Yen A, Zipfel J. Chemistry of rocks and soils at Meridiani Planum from the Alpha Particle X-ray Spectrometer. Science 2004; 306:1746-9. [PMID: 15576611 DOI: 10.1126/science.1104358] [Citation(s) in RCA: 314] [Impact Index Per Article: 15.7] [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: 11/02/2022]
Abstract
The Alpha Particle X-ray Spectrometer on the Opportunity rover determined major and minor elements of soils and rocks in Meridiani Planum. Chemical compositions differentiate between basaltic rocks, evaporite-rich rocks, basaltic soils, and hematite-rich soils. Although soils are compositionally similar to those at previous landing sites, differences in iron and some minor element concentrations signify the addition of local components. Rocky outcrops are rich in sulfur and variably enriched in bromine relative to chlorine. The interaction with water in the past is indicated by the chemical features in rocks and soils at this site.
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Affiliation(s)
- R Rieder
- Max-Planck-Institut für Chemie, J. J. Becher-Weg 27, D-55128 Mainz, Germany.
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Squyres SW, Grotzinger JP, Arvidson RE, Bell JF, Calvin W, Christensen PR, Clark BC, Crisp JA, Farrand WH, Herkenhoff KE, Johnson JR, Klingelhöfer G, Knoll AH, McLennan SM, McSween HY, Morris RV, Rice JW, Rieder R, Soderblom LA. In situ evidence for an ancient aqueous environment at Meridiani Planum, Mars. Science 2004; 306:1709-14. [PMID: 15576604 DOI: 10.1126/science.1104559] [Citation(s) in RCA: 244] [Impact Index Per Article: 12.2] [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
Sedimentary rocks at Eagle crater in Meridiani Planum are composed of fine-grained siliciclastic materials derived from weathering of basaltic rocks, sulfate minerals (including magnesium sulfate and jarosite) that constitute several tens of percent of the rock by weight, and hematite. Cross-stratification observed in rock outcrops indicates eolian and aqueous transport. Diagenetic features include hematite-rich concretions and crystal-mold vugs. We interpret the rocks to be a mixture of chemical and siliciclastic sediments with a complex diagenetic history. The environmental conditions that they record include episodic inundation by shallow surface water, evaporation, and desiccation. The geologic record at Meridiani Planum suggests that conditions were suitable for biological activity for a period of time in martian history.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA.
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Soderblom LA, Anderson RC, Arvidson RE, Bell JF, Cabrol NA, Calvin W, Christensen PR, Clark BC, Economou T, Ehlmann BL, Farrand WH, Fike D, Gellert R, Glotch TD, Golombek MP, Greeley R, Grotzinger JP, Herkenhoff KE, Jerolmack DJ, Johnson JR, Jolliff B, Klingelhöfer G, Knoll AH, Learner ZA, Li R, Malin MC, McLennan SM, McSween HY, Ming DW, Morris RV, Rice JW, Richter L, Rieder R, Rodionov D, Schröder C, Seelos FP, Soderblom JM, Squyres SW, Sullivan R, Watters WA, Weitz CM, Wyatt MB, Yen A, Zipfel J. Soils of Eagle Crater and Meridiani Planum at the Opportunity Rover Landing Site. Science 2004; 306:1723-6. [PMID: 15576606 DOI: 10.1126/science.1105127] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.9] [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: 11/02/2022]
Abstract
The soils at the Opportunity site are fine-grained basaltic sands mixed with dust and sulfate-rich outcrop debris. Hematite is concentrated in spherules eroded from the strata. Ongoing saltation exhumes the spherules and their fragments, concentrating them at the surface. Spherules emerge from soils coated, perhaps from subsurface cementation, by salts. Two types of vesicular clasts may represent basaltic sand sources. Eolian ripples, armored by well-sorted hematite-rich grains, pervade Meridiani Planum. The thickness of the soil on the plain is estimated to be about a meter. The flatness and thin cover suggest that the plain may represent the original sedimentary surface.
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Squyres SW, Arvidson RE, Bell JF, Brückner J, Cabrol NA, Calvin W, Carr MH, Christensen PR, Clark BC, Crumpler L, Des Marais DJ, D'Uston C, Economou T, Farmer J, Farrand W, Folkner W, Golombek M, Gorevan S, Grant JA, Greeley R, Grotzinger J, Haskin L, Herkenhoff KE, Hviid S, Johnson J, Klingelhöfer G, Knoll A, Landis G, Lemmon M, Li R, Madsen MB, Malin MC, McLennan SM, McSween HY, Ming DW, Moersch J, Morris RV, Parker T, Rice JW, Richter L, Rieder R, Sims M, Smith M, Smith P, Soderblom LA, Sullivan R, Wänke H, Wdowiak T, Wolff M, Yen A. The Spirit Rover's Athena science investigation at Gusev Crater, Mars. Science 2004; 305:794-9. [PMID: 15297657 DOI: 10.1126/science.1100194] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Mars Exploration Rover Spirit and its Athena science payload have been used to investigate a landing site in Gusev crater. Gusev is hypothesized to be the site of a former lake, but no clear evidence for lacustrine sedimentation has been found to date. Instead, the dominant lithology is basalt, and the dominant geologic processes are impact events and eolian transport. Many rocks exhibit coatings and other characteristics that may be evidence for minor aqueous alteration. Any lacustrine sediments that may exist at this location within Gusev apparently have been buried by lavas that have undergone subsequent impact disruption.
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Affiliation(s)
- S W Squyres
- Department of Astronomy, Cornell University, Ithaca, NY 14853, USA.
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McSween HY, Arvidson RE, Bell JF, Blaney D, Cabrol NA, Christensen PR, Clark BC, Crisp JA, Crumpler LS, Des Marais DJ, Farmer JD, Gellert R, Ghosh A, Gorevan S, Graff T, Grant J, Haskin LA, Herkenhoff KE, Johnson JR, Jolliff BL, Klingelhoefer G, Knudson AT, McLennan S, Milam KA, Moersch JE, Morris RV, Rieder R, Ruff SW, De Souza PA, Squyres SW, Wänke H, Wang A, Wyatt MB, Yen A, Zipfel J. Basaltic rocks analyzed by the Spirit Rover in Gusev Crater. Science 2004; 305:842-5. [PMID: 15297668 DOI: 10.1126/science.1099851] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
The Spirit landing site in Gusev Crater on Mars contains dark, fine-grained, vesicular rocks interpreted as lavas. Pancam and Mini-Thermal Emission Spectrometer (Mini-TES) spectra suggest that all of these rocks are similar but have variable coatings and dust mantles. Magnified images of brushed and abraded rock surfaces show alteration rinds and veins. Rock interiors contain </=25% megacrysts. Chemical analyses of rocks by the Alpha Particle X-ray Spectrometer are consistent with picritic basalts, containing normative olivine, pyroxenes, plagioclase, and accessory FeTi oxides. Mössbauer, Pancam, and Mini-TES spectra confirm the presence of olivine, magnetite, and probably pyroxene. These basalts extend the known range of rock compositions composing the martian crust.
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Affiliation(s)
- H Y McSween
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996-1410, USA.
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Gellert R, Rieder R, Anderson RC, Brückner J, Clark BC, Dreibus G, Economou T, Klingelhöfer G, Lugmair GW, Ming DW, Squyres SW, D'Uston C, Wänke H, Yen A, Zipfel J. Chemistry of Rocks and Soils in Gusev Crater from the Alpha Particle X-ray Spectrometer. Science 2004; 305:829-32. [PMID: 15297665 DOI: 10.1126/science.1099913] [Citation(s) in RCA: 254] [Impact Index Per Article: 12.7] [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: 11/02/2022]
Abstract
The alpha particle x-ray spectrometer on the Spirit rover determined major and minor elements of soils and rocks in Gusev crater in order to unravel the crustal evolution of planet Mars. The composition of soils is similar to those at previous landing sites, as a result of global mixing and distribution by dust storms. Rocks (fresh surfaces exposed by the rock abrasion tool) resemble volcanic rocks of primitive basaltic composition with low intrinsic potassium contents. High abundance of bromine (up to 170 parts per million) in rocks may indicate the alteration of surfaces formed during a past period of aqueous activity in Gusev crater.
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Affiliation(s)
- R Gellert
- Max-Planck-Institut für Chemie, J. J. Becher-Weg 27, D-55128 Mainz, Germany.
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Abstract
The CIDA (Cometary and Interstellar Dust Analyzer) instrument on the Stardust spacecraft is a time-of-flight mass spectrometer used to analyze ions formed when fast dust particles strike the instrument's target. In the spectra of 45 presumably interstellar particles, quinone derivates were identified as constituents in the organic component. The 29 spectra obtained during the flyby of Comet 81P/Wild 2 confirm the predominance of organic matter. In moving from interstellar to cometary dust, the organic material seems to lose most of its hydrogen and oxygen as water and carbon monoxide. These are now present in the comet as gas phases, whereas the dust is rich in nitrogen-containing species. No traces of amino acids were found. We detected sulfur ions in one spectrum, which suggests that sulfur species are important in cometary organics.
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Affiliation(s)
- J Kissel
- Max-Planck-Institut fur Aeronomie, Max-Planck-Strasse 2, D-37191 Katlenburg-Lindau, Germany
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Clark BC, Adams DA. Experimental measurements of the radiation hazards associated with manned space flights. Life Sci Space Res 2002; 3:29-47. [PMID: 12035805] [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] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Tissue-equivalent ionization chambers of special design have been flown on U.S. satellites to determine dose-rate levels in space. A chamber shielded by 4.7 g/cm2 measured doses from energetic protons in the inner Van Allen belt and bremsstrahlung radiation produced by relativistic electrons from the artificial radiation belt formed in July 1962. In November 1962, the maximum dose-rate in space for this shield was 30 rad/hr. Behind 0.4 g/cm2 shielding, the dose-rate peak was 20000 rad/hr. These doses have been determined to be due to artificial electrons in most regions of space, masking the dose arising from energetic protons.
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Affiliation(s)
- B C Clark
- Biophysics Branch, Air Force Weapons Laboratory, Kirtland AFB, New Mexico, USA
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Clark BC, Chamblee TS, Iacobucci GA. Micellar-induced selectivity and rate enhancement in the acid-catalyzed cyclization and rearrangement of monoterpenes. The solvolysis of linalyl and geranyl acetates. J Org Chem 2002. [DOI: 10.1021/jo00266a007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Clark BC, Chamblee TS, Iacobucci GA. Acid-catalyzed cyclization of terpenoids in a micellar system. Selectivity and rate enhancement in the cyclization of citronellal. J Org Chem 2002. [DOI: 10.1021/jo00197a054] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [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
It is now well-accepted that both lunar and martian materials are represented in the meteorite collections. Early suggestions that viable organisms might survive natural transport between planets have not yet been thoroughly examined. The concept of Planetary Interchange of Bioactive Material (PIBM) is potentially relevant to the conditions under which life originated. PIBM has been also invoked to infer that the potential danger to Earth from martian materials is non-existent, an inference with, however, many pitfalls. Numerous impediments to efficient transfer of viable organisms exist. In this work, the lethality of space radiation during long transients and the biasing of launched objects toward materials unlikely to host abundant organisms are examined and shown to reduce the likelihood of successful transfer by orders of magnitude. It is also shown that martian meteorites studied to date assuredly have been subjected to sterilizing levels of ionizing radiation in space. PIBM considerations apply to both the solar system locale(s) of the origin of life and to the applicability of planetary protection protocols to preserve the biospheres of planetary bodies, including our own.
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Affiliation(s)
- B C Clark
- Lockheed Martin Astronautics, POB 179, Denver, CO 80201, USA
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Clark BC. Mars/viking 25th Anniversary Tribute. Viking redux: Viking success and lessons for the future. Astrobiology 2001; 1:509-512. [PMID: 12448986 DOI: 10.1089/153110701753593937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- B C Clark
- Lockheed Martin Astronautics, Denver, CO, USA
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41
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Clifford SM, Crisp D, Fisher DA, Herkenhoff KE, Smrekar SE, Thomas PC, Wynn-Williams DD, Zurek RW, Barnes JR, Bills BG, Blake EW, Calvin WM, Cameron JM, Carr MH, Christensen PR, Clark BC, Clow GD, Cutts JA, Dahl-Jensen D, Durham WB, Fanale FP, Farmer JD, Forget F, Gotto-Azuma K, Zwally HJ. The state and future of Mars polar science and exploration. Icarus 2000; 144:210-242. [PMID: 11543391 DOI: 10.1006/icar.1999.6290] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [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: 05/23/2023]
Abstract
As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of approximately 10(6) km2 and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young--preserving a record of the seasonal and climatic cycling of atmospheric CO2, H2O, and dust over the past approximately 10(5)-10(8) years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet--documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason--providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.
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Affiliation(s)
- S M Clifford
- Lunar and Planetary Institute, Houston, Texas 77058, USA.
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Clark BC, Baker AL, Cheng AF, Clemett SJ, McKay D, McSween HY, Pieters CM, Thomas P, Zolensky M. Survival of life on asteroids, comets and other small bodies. ORIGINS LIFE EVOL B 1999; 29:521-45. [PMID: 10573692 DOI: 10.1023/a:1006589213075] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The ability of living organisms to survive on the smaller bodies in our solar system is examined. The three most significant sterilizing effects include ionizing radiation, prolonged extreme vacuum, and relentless thermal inactivation. Each could be effectively lethal, and even more so in combination, if organisms at some time resided in the surfaces of airless small bodies located near or in the inner solar system. Deep within volatile-rich bodies, certain environments theoretically might provide protection of dormant organisms against these sterilizing factors. Sterility of surface materials to tens or hundreds of centimeters of depth appears inevitable, and to greater depths for bodies which have resided for long periods sunward of about 2 A.U.
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Affiliation(s)
- B C Clark
- Advanced Planetary Studies Group, Lockheed Martin Astronautics, Denver, CO, USA
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43
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Sreekumar GP, Pardinas J, Wong CQ, Whiting D, Katz HI, Price V, Zlotogorski A, Roberts J, Clark BC, Stenn K, Parimoo S. Serum androgens and genetic linkage analysis in early onset androgenetic alopecia. J Invest Dermatol 1999; 113:277-9. [PMID: 10469317 DOI: 10.1046/j.1523-1747.1999.00659.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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45
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Chamblee TS, Karelitz RL, Radford T, Clark BC. Identification of Sesquiterpenes in Citrus Essential Oils by Cryofocusing GC/FT-IR. Journal of Essential Oil Research 1997. [DOI: 10.1080/10412905.1997.9699448] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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46
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Brownlee DE, Tsou P, Atkins KL, Yen CW, Vellinga JM, Price S, Clark BC. STARDUST: finessing expensive cometary sample returns. Acta Astronaut 1996; 39:51-60. [PMID: 11540764 DOI: 10.1016/s0094-5765(96)00122-1] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The STARDUST Discovery mission will collect samples of cometary coma and interstellar dust and return them to Earth. Five years after launch in February 1999, coma dust in the 1- to 100-micrometers size range will be captured by impact into ultra-low-density silica aerogel during a 6 kms-1 flyby of Comet Wild 2. The returned samples will be investigated at laboratories where the most critical information on these primitive materials is retained. The Jet Propulsion Laboratory will provide project management with Lockheed Martin Astronauts as the spacecraft industrial partner. STARDUST management will aggressively and innovatively achieve cost control through the use of Total Quality Management principles, the chief of which will be organization in a Project Engineering and Integration Team that "flattens" the traditional hierarchical structure by including all project elements from the beginning, in a concurrent engineering framework focusing on evolving Integrated Mission Capability.
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Affiliation(s)
- D E Brownlee
- University of Washington, Department of Astronomy, Seattle 98195, USA
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Hoffmann GW, Ray L, Read D, Worm S, Barlett ML, Green AA, Storm B, Clark BC, Hama S, Mercer RL. Measurement of the polarization transfer parameter DNN for 12,13C(p. Phys Rev C Nucl Phys 1996; 53:1974-1976. [PMID: 9971158 DOI: 10.1103/physrevc.53.1974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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48
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Ray AK, Bird PB, Iacobucci GA, Clark BC. Functionality of gum arabic. Fractionation, characterization and evaluation of gum fractions in citrus oil emulsions and model beverages. Food Hydrocoll 1995. [DOI: 10.1016/s0268-005x(09)80274-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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49
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Kurth LJ, Clark BC, Cooper ED, Hama S, Mercer RL, Ray L, Hoffmann GW. Relativistic impulse approximation treatment of the elastic scattering of 400 MeV pi +/- on 28Si. Phys Rev C Nucl Phys 1994; 50:2624-2626. [PMID: 9969956 DOI: 10.1103/physrevc.50.2624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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50
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Kurth L, Clark BC, Cooper ED, Hama S, Shim S, Mercer RL, Ray L, Hoffmann GW. Dirac coupled channel calculations for proton inelastic scattering from spherically symmetric nuclei for projectile energies of 362, 500, and 800 MeV. Phys Rev C Nucl Phys 1994; 49:2086-2103. [PMID: 9969440 DOI: 10.1103/physrevc.49.2086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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