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Wilson JK, Spence HE, Schwadron NA, Case AW, Looper MD, Jordan AP, de Wet W, Kasper J. Precise Detections of Solar Particle Events and a New View of the Moon. GEOPHYSICAL RESEARCH LETTERS 2020; 47:e2019GL085522. [PMID: 33688109 PMCID: PMC7939032 DOI: 10.1029/2019gl085522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 12/18/2019] [Indexed: 06/12/2023]
Abstract
We have invented a new method for detecting solar particle events using data from the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO). Using a simple function of the total particle detection rates from four of CRaTER's six detectors, we can precisely identify solar energetic particle event periods in the CRaTER data archive. During solar-quiet periods we map the distribution of a mare-associated mixture of elements in the lunar regolith using this new method. The new map of the moon probably reflects an as-yet unknown combination of lunar albedo protons, neutrons, and gamma rays, and most closely resembles Lunar Prospector maps of gamma rays characteristic of thorium and iron. This result will lead to multiple follow-up studies of lunar albedo particles and may also contribute to the study of diurnally-varying hydrogenation of the lunar regolith.
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Affiliation(s)
- Jody K Wilson
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffet Field, California, USA
| | - Harlan E Spence
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffet Field, California, USA
| | - Nathan A Schwadron
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffet Field, California, USA
| | - Anthony W Case
- Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Mark D Looper
- The Aerospace Corporation, El Segundo, California, USA
| | - Andrew P Jordan
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
- Solar System Exploration Research Virtual Institute, NASA Ames Research Center, Moffet Field, California, USA
| | - Wouter de Wet
- Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Justin Kasper
- Michigan Institute for Research in Astrophysics, University of Michigan, Ann Arbor, Michigan, USA
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Prettyman TH, Yamashita N, Toplis MJ, McSween HY, Schörghofer N, Marchi S, Feldman WC, Castillo-Rogez J, Forni O, Lawrence DJ, Ammannito E, Ehlmann BL, Sizemore HG, Joy SP, Polanskey CA, Rayman MD, Raymond CA, Russell CT. Extensive water ice within Ceres' aqueously altered regolith: Evidence from nuclear spectroscopy. Science 2016; 355:55-59. [PMID: 27980087 DOI: 10.1126/science.aah6765] [Citation(s) in RCA: 148] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Accepted: 11/23/2016] [Indexed: 11/03/2022]
Abstract
The surface elemental composition of dwarf planet Ceres constrains its regolith ice content, aqueous alteration processes, and interior evolution. Using nuclear spectroscopy data acquired by NASA's Dawn mission, we determined the concentrations of elemental hydrogen, iron, and potassium on Ceres. The data show that surface materials were processed by the action of water within the interior. The non-icy portion of Ceres' carbon-bearing regolith contains similar amounts of hydrogen to those present in aqueously altered carbonaceous chondrites; however, the concentration of iron on Ceres is lower than in the aforementioned chondrites. This allows for the possibility that Ceres experienced modest ice-rock fractionation, resulting in differences between surface and bulk composition. At mid-to-high latitudes, the regolith contains high concentrations of hydrogen, consistent with broad expanses of water ice, confirming theoretical predictions that ice can survive for billions of years just beneath the surface.
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Affiliation(s)
- T H Prettyman
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USA.
| | - N Yamashita
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USA
| | - M J Toplis
- Institut de Recherche d'Astrophysique et Planétologie, CNRS, Université Paul Sabatier, Toulouse 31400, France
| | - H Y McSween
- Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN 37996-1410, USA
| | - N Schörghofer
- University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822, USA
| | - S Marchi
- Southwest Research Institute, Boulder, CO 80302, USA
| | - W C Feldman
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USA
| | - J Castillo-Rogez
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109-8099, USA
| | - O Forni
- Institut de Recherche d'Astrophysique et Planétologie, CNRS, Université Paul Sabatier, Toulouse 31400, France
| | - D J Lawrence
- Johns Hopkins University, Applied Physics Laboratory, Laurel, MD 20723, USA
| | - E Ammannito
- Earth Planetary and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1567, USA
| | - B L Ehlmann
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109-8099, USA.,Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - H G Sizemore
- Planetary Science Institute, 1700 East Fort Lowell, Suite 106, Tucson, AZ 85719-2395, USA
| | - S P Joy
- Earth Planetary and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1567, USA
| | - C A Polanskey
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109-8099, USA
| | - M D Rayman
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109-8099, USA
| | - C A Raymond
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109-8099, USA
| | - C T Russell
- Earth Planetary and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095-1567, USA
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Solomon SC, McNutt RL, Watters TR, Lawrence DJ, Feldman WC, Head JW, Krimigis SM, Murchie SL, Phillips RJ, Slavin JA, Zuber MT. Return to Mercury: A Global Perspective on MESSENGER's First Mercury Flyby. Science 2008; 321:59-62. [DOI: 10.1126/science.1159706] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Sean C. Solomon
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Ralph L. McNutt
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Thomas R. Watters
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - David J. Lawrence
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - William C. Feldman
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - James W. Head
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Stamatios M. Krimigis
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Scott L. Murchie
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Roger J. Phillips
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - James A. Slavin
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
| | - Maria T. Zuber
- Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, USA
- Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, USA
- Center for Earth and Planetary Studies, National Air and Space Museum, Smithsonian Institution, Washington, DC 20560, USA
- Planetary Science Institute, Tucson, AZ 85719, USA
- Department of Geological Sciences, Brown University, Providence, RI 02912, USA
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