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Waite JH, Perryman RS, Perry ME, Miller KE, Bell J, Cravens TE, Glein CR, Grimes J, Hedman M, Cuzzi J, Brockwell T, Teolis B, Moore L, Mitchell DG, Persoon A, Kurth WS, Wahlund JE, Morooka M, Hadid LZ, Chocron S, Walker J, Nagy A, Yelle R, Ledvina S, Johnson R, Tseng W, Tucker OJ, Ip WH. Chemical interactions between Saturn’s atmosphere and its rings. Science 2018; 362:362/6410/eaat2382. [DOI: 10.1126/science.aat2382] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 09/10/2018] [Indexed: 11/03/2022]
Abstract
The Pioneer and Voyager spacecraft made close-up measurements of Saturn’s ionosphere and upper atmosphere in the 1970s and 1980s that suggested a chemical interaction between the rings and atmosphere. Exploring this interaction provides information on ring composition and the influence on Saturn’s atmosphere from infalling material. The Cassini Ion Neutral Mass Spectrometer sampled in situ the region between the D ring and Saturn during the spacecraft’s Grand Finale phase. We used these measurements to characterize the atmospheric structure and material influx from the rings. The atmospheric He/H2 ratio is 10 to 16%. Volatile compounds from the rings (methane; carbon monoxide and/or molecular nitrogen), as well as larger organic-bearing grains, are flowing inward at a rate of 4800 to 45,000 kilograms per second.
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2
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Jakosky BM, Slipski M, Benna M, Mahaffy P, Elrod M, Yelle R, Stone S, Alsaeed N. Mars' atmospheric history derived from upper-atmosphere measurements of 38Ar/ 36Ar. Science 2017; 355:1408-1410. [PMID: 28360326 DOI: 10.1126/science.aai7721] [Citation(s) in RCA: 155] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 03/06/2017] [Indexed: 11/02/2022]
Abstract
The history of Mars' atmosphere is important for understanding the geological evolution and potential habitability of the planet. We determine the amount of gas lost to space through time using measurements of the upper-atmospheric structure made by the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. We derive the structure of 38Ar/36Ar between the homopause and exobase altitudes. Fractionation of argon occurs as a result of loss of gas to space by pickup-ion sputtering, which preferentially removes the lighter atom. The measurements require that 66% of the atmospheric argon has been lost to space. Thus, a large fraction of Mars' atmospheric gas has been lost to space, contributing to the transition in climate from an early, warm, wet environment to today's cold, dry atmosphere.
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Affiliation(s)
| | - M Slipski
- University of Colorado, Boulder, CO, USA
| | - M Benna
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - P Mahaffy
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - M Elrod
- NASA/Goddard Spaceflight Center, Greenbelt, MD, USA
| | - R Yelle
- University of Arizona, Tucson, AZ, USA
| | - S Stone
- University of Arizona, Tucson, AZ, USA
| | - N Alsaeed
- University of Colorado, Boulder, CO, USA.,American University of Sharjah, Sharjah, United Arab Emirates
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3
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Jakosky BM, Grebowsky JM, Luhmann JG, Connerney J, Eparvier F, Ergun R, Halekas J, Larson D, Mahaffy P, McFadden J, Mitchell DF, Schneider N, Zurek R, Bougher S, Brain D, Ma YJ, Mazelle C, Andersson L, Andrews D, Baird D, Baker D, Bell JM, Benna M, Chaffin M, Chamberlin P, Chaufray YY, Clarke J, Collinson G, Combi M, Crary F, Cravens T, Crismani M, Curry S, Curtis D, Deighan J, Delory G, Dewey R, DiBraccio G, Dong C, Dong Y, Dunn P, Elrod M, England S, Eriksson A, Espley J, Evans S, Fang X, Fillingim M, Fortier K, Fowler CM, Fox J, Gröller H, Guzewich S, Hara T, Harada Y, Holsclaw G, Jain SK, Jolitz R, Leblanc F, Lee CO, Lee Y, Lefevre F, Lillis R, Livi R, Lo D, Mayyasi M, McClintock W, McEnulty T, Modolo R, Montmessin F, Morooka M, Nagy A, Olsen K, Peterson W, Rahmati A, Ruhunusiri S, Russell CT, Sakai S, Sauvaud JA, Seki K, Steckiewicz M, Stevens M, Stewart AIF, Stiepen A, Stone S, Tenishev V, Thiemann E, Tolson R, Toublanc D, Vogt M, Weber T, Withers P, Woods T, Yelle R. MAVEN observations of the response of Mars to an interplanetary coronal mass ejection. Science 2015; 350:aad0210. [PMID: 26542576 DOI: 10.1126/science.aad0210] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [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
Coupling between the lower and upper atmosphere, combined with loss of gas from the upper atmosphere to space, likely contributed to the thin, cold, dry atmosphere of modern Mars. To help understand ongoing ion loss to space, the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft made comprehensive measurements of the Mars upper atmosphere, ionosphere, and interactions with the Sun and solar wind during an interplanetary coronal mass ejection impact in March 2015. Responses include changes in the bow shock and magnetosheath, formation of widespread diffuse aurora, and enhancement of pick-up ions. Observations and models both show an enhancement in escape rate of ions to space during the event. Ion loss during solar events early in Mars history may have been a major contributor to the long-term evolution of the Mars atmosphere.
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Affiliation(s)
| | - J M Grebowsky
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J G Luhmann
- University of California at Berkeley, Berkeley, CA, USA
| | - J Connerney
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - F Eparvier
- University of Colorado, Boulder, CO, USA
| | - R Ergun
- University of Colorado, Boulder, CO, USA
| | - J Halekas
- University of Iowa, Iowa City, IA, USA
| | - D Larson
- University of California at Berkeley, Berkeley, CA, USA
| | - P Mahaffy
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J McFadden
- University of California at Berkeley, Berkeley, CA, USA
| | - D F Mitchell
- University of California at Berkeley, Berkeley, CA, USA
| | | | - R Zurek
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - S Bougher
- University of Michigan, Ann Arbor, MI, USA
| | - D Brain
- University of Colorado, Boulder, CO, USA
| | - Y J Ma
- University of California at Los Angeles, Los Angeles, CA, USA
| | - C Mazelle
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | | | - D Andrews
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - D Baird
- NASA/Johnson Space Center, Houston, TX, USA
| | - D Baker
- University of Colorado, Boulder, CO, USA
| | - J M Bell
- National Institute of Aerospace, Hampton, VA, USA
| | - M Benna
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Chaffin
- University of Colorado, Boulder, CO, USA
| | - P Chamberlin
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - Y-Y Chaufray
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - J Clarke
- Boston University, Boston, MA, USA
| | - G Collinson
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Combi
- University of Michigan, Ann Arbor, MI, USA
| | - F Crary
- University of Colorado, Boulder, CO, USA
| | - T Cravens
- University of Kansas, Lawrence, KS, USA
| | - M Crismani
- University of Colorado, Boulder, CO, USA
| | - S Curry
- University of California at Berkeley, Berkeley, CA, USA
| | - D Curtis
- University of California at Berkeley, Berkeley, CA, USA
| | - J Deighan
- University of Colorado, Boulder, CO, USA
| | - G Delory
- University of California at Berkeley, Berkeley, CA, USA
| | - R Dewey
- University of Colorado, Boulder, CO, USA
| | - G DiBraccio
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - C Dong
- University of Michigan, Ann Arbor, MI, USA
| | - Y Dong
- University of Colorado, Boulder, CO, USA
| | - P Dunn
- University of California at Berkeley, Berkeley, CA, USA
| | - M Elrod
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S England
- University of California at Berkeley, Berkeley, CA, USA
| | - A Eriksson
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - J Espley
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S Evans
- Computational Physics, Inc., Boulder, CO, USA
| | - X Fang
- University of Colorado, Boulder, CO, USA
| | - M Fillingim
- University of California at Berkeley, Berkeley, CA, USA
| | - K Fortier
- University of Colorado, Boulder, CO, USA
| | - C M Fowler
- University of Colorado, Boulder, CO, USA
| | - J Fox
- Wright State University, Dayton, OH, USA
| | - H Gröller
- University of Arizona, Tucson, AZ, USA
| | - S Guzewich
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - T Hara
- University of California at Berkeley, Berkeley, CA, USA
| | - Y Harada
- University of California at Berkeley, Berkeley, CA, USA
| | - G Holsclaw
- University of Colorado, Boulder, CO, USA
| | - S K Jain
- University of Colorado, Boulder, CO, USA
| | - R Jolitz
- University of California at Berkeley, Berkeley, CA, USA
| | - F Leblanc
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - C O Lee
- University of California at Berkeley, Berkeley, CA, USA
| | - Y Lee
- University of Michigan, Ann Arbor, MI, USA
| | - F Lefevre
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - R Lillis
- University of California at Berkeley, Berkeley, CA, USA
| | - R Livi
- University of California at Berkeley, Berkeley, CA, USA
| | - D Lo
- University of Arizona, Tucson, AZ, USA
| | | | | | - T McEnulty
- University of Colorado, Boulder, CO, USA
| | - R Modolo
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - F Montmessin
- Laboratoire atmosphères, milieux et observations spatiales (LATMOS)-CNRS, Paris, France
| | - M Morooka
- University of Colorado, Boulder, CO, USA
| | - A Nagy
- University of Michigan, Ann Arbor, MI, USA
| | - K Olsen
- University of Michigan, Ann Arbor, MI, USA
| | - W Peterson
- University of Colorado, Boulder, CO, USA
| | - A Rahmati
- University of Kansas, Lawrence, KS, USA
| | | | - C T Russell
- University of California at Los Angeles, Los Angeles, CA, USA
| | - S Sakai
- University of Kansas, Lawrence, KS, USA
| | - J-A Sauvaud
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - K Seki
- Nagoya University, Nagoya, Japan
| | - M Steckiewicz
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Stevens
- Naval Research Laboratory, Washington, DC, USA
| | | | - A Stiepen
- University of Colorado, Boulder, CO, USA
| | - S Stone
- University of Arizona, Tucson, AZ, USA
| | - V Tenishev
- University of Michigan, Ann Arbor, MI, USA
| | - E Thiemann
- University of Colorado, Boulder, CO, USA
| | - R Tolson
- North Carolina State University, Raleigh, NC, USA
| | - D Toublanc
- CNRS-Institut de Recherche en Astrophysique et Planétologie (IRAP), Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Vogt
- Boston University, Boston, MA, USA
| | - T Weber
- University of Colorado, Boulder, CO, USA
| | | | - T Woods
- University of Colorado, Boulder, CO, USA
| | - R Yelle
- University of Arizona, Tucson, AZ, USA
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4
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Bougher S, Jakosky B, Halekas J, Grebowsky J, Luhmann J, Mahaffy P, Connerney J, Eparvier F, Ergun R, Larson D, McFadden J, Mitchell D, Schneider N, Zurek R, Mazelle C, Andersson L, Andrews D, Baird D, Baker DN, Bell JM, Benna M, Brain D, Chaffin M, Chamberlin P, Chaufray JY, Clarke J, Collinson G, Combi M, Crary F, Cravens T, Crismani M, Curry S, Curtis D, Deighan J, Delory G, Dewey R, DiBraccio G, Dong C, Dong Y, Dunn P, Elrod M, England S, Eriksson A, Espley J, Evans S, Fang X, Fillingim M, Fortier K, Fowler CM, Fox J, Gröller H, Guzewich S, Hara T, Harada Y, Holsclaw G, Jain SK, Jolitz R, Leblanc F, Lee CO, Lee Y, Lefevre F, Lillis R, Livi R, Lo D, Ma Y, Mayyasi M, McClintock W, McEnulty T, Modolo R, Montmessin F, Morooka M, Nagy A, Olsen K, Peterson W, Rahmati A, Ruhunusiri S, Russell CT, Sakai S, Sauvaud JA, Seki K, Steckiewicz M, Stevens M, Stewart AIF, Stiepen A, Stone S, Tenishev V, Thiemann E, Tolson R, Toublanc D, Vogt M, Weber T, Withers P, Woods T, Yelle R. Early MAVEN Deep Dip campaign reveals thermosphere and ionosphere variability. Science 2015; 350:aad0459. [PMID: 26542579 DOI: 10.1126/science.aad0459] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [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 Mars Atmosphere and Volatile Evolution (MAVEN) mission, during the second of its Deep Dip campaigns, made comprehensive measurements of martian thermosphere and ionosphere composition, structure, and variability at altitudes down to ~130 kilometers in the subsolar region. This altitude range contains the diffusively separated upper atmosphere just above the well-mixed atmosphere, the layer of peak extreme ultraviolet heating and primary reservoir for atmospheric escape. In situ measurements of the upper atmosphere reveal previously unmeasured populations of neutral and charged particles, the homopause altitude at approximately 130 kilometers, and an unexpected level of variability both on an orbit-to-orbit basis and within individual orbits. These observations help constrain volatile escape processes controlled by thermosphere and ionosphere structure and variability.
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Affiliation(s)
- S Bougher
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA.
| | - B Jakosky
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J Halekas
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - J Grebowsky
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J Luhmann
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - P Mahaffy
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J Connerney
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - F Eparvier
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Ergun
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - D Larson
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - J McFadden
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Mitchell
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - N Schneider
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Zurek
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA
| | - C Mazelle
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - L Andersson
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - D Andrews
- Swedish Institute of Space Physics, Kiruna, Sweden
| | - D Baird
- NASA/Johnson Space Center, Houston, TX, USA
| | - D N Baker
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J M Bell
- National Institute of Aerospace, Hampton, VA, USA
| | - M Benna
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - D Brain
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - M Chaffin
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Chamberlin
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - J-Y Chaufray
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - J Clarke
- Department of Astronomy, Boston University, Boston, MA, USA
| | - G Collinson
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - M Combi
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - F Crary
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - T Cravens
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - M Crismani
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S Curry
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Curtis
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - J Deighan
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - G Delory
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - R Dewey
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - G DiBraccio
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - C Dong
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - Y Dong
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Dunn
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - M Elrod
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S England
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - A Eriksson
- Swedish Institute of Space Physics, Kiruna, Sweden
| | - J Espley
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - S Evans
- Computational Physics, Springfield, VA, USA
| | - X Fang
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - M Fillingim
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - K Fortier
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - C M Fowler
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - J Fox
- Department of Physics, Wright State University, Fairborn, OH, USA
| | - H Gröller
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - S Guzewich
- NASA/Goddard Space Flight Center, Greenbelt, MD, USA
| | - T Hara
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Y Harada
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - G Holsclaw
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S K Jain
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Jolitz
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - F Leblanc
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - C O Lee
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - Y Lee
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - F Lefevre
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - R Lillis
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - R Livi
- Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA, USA
| | - D Lo
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - Y Ma
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA, USA
| | - M Mayyasi
- Department of Astronomy, Boston University, Boston, MA, USA
| | - W McClintock
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - T McEnulty
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Modolo
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - F Montmessin
- Laboratoire Atmosphères, Milieux, Observations Spatiales /CNRS, Verrieres-le-Buisson, France
| | - M Morooka
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Nagy
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - K Olsen
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - W Peterson
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Rahmati
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - S Ruhunusiri
- Department of Physics and Astronomy, University of Iowa, Iowa City, IA, USA
| | - C T Russell
- Institute of Geophysics and Planetary Physics, University of California, Los Angeles, Los Angeles, CA, USA
| | - S Sakai
- Department of Physics and Astronomy, University of Kansas, Lawrence, KS, USA
| | - J-A Sauvaud
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - K Seki
- Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi, Japan
| | - M Steckiewicz
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Stevens
- Naval Research Laboratory, Washington, DC, USA
| | - A I F Stewart
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - A Stiepen
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - S Stone
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
| | - V Tenishev
- CLaSP Department, University of Michigan, Ann Arbor, MI, USA
| | - E Thiemann
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Tolson
- National Institute of Aerospace, Hampton, VA, USA
| | - D Toublanc
- CNRS/Institut de Recherche en Astrophysique et Planétologie, Toulouse, France. University Paul Sabatier, Toulouse, France
| | - M Vogt
- Department of Astronomy, Boston University, Boston, MA, USA
| | - T Weber
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - P Withers
- Department of Astronomy, Boston University, Boston, MA, USA
| | - T Woods
- Laboratory for Atmospheric and Space Physics, University. of Colorado, Boulder, CO, USA
| | - R Yelle
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ, USA
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5
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Andersson L, Weber TD, Malaspina D, Crary F, Ergun RE, Delory GT, Fowler CM, Morooka MW, McEnulty T, Eriksson AI, Andrews DJ, Horanyi M, Collette A, Yelle R, Jakosky BM. Dust observations at orbital altitudes surrounding Mars. Science 2015; 350:aad0398. [PMID: 26542578 DOI: 10.1126/science.aad0398] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [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
Dust is common close to the martian surface, but no known process can lift appreciable concentrations of particles to altitudes above ~150 kilometers. We present observations of dust at altitudes ranging from 150 to above 1000 kilometers by the Langmuir Probe and Wave instrument on the Mars Atmosphere and Volatile Evolution spacecraft. Based on its distribution, we interpret this dust to be interplanetary in origin. A comparison with laboratory measurements indicates that the dust grain size ranges from 1 to 12 micrometers, assuming a typical grain velocity of ~18 kilometers per second. These direct observations of dust entering the martian atmosphere improve our understanding of the sources, sinks, and transport of interplanetary dust throughout the inner solar system and the associated impacts on Mars's atmosphere.
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Affiliation(s)
- L Andersson
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA.
| | - T D Weber
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - D Malaspina
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - F Crary
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - R E Ergun
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - G T Delory
- Space Science Laboratory, University of California-Berkeley, Berkeley, CA 94720, USA
| | - C M Fowler
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - M W Morooka
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - T McEnulty
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - A I Eriksson
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - D J Andrews
- Swedish Institute of Space Physics, Uppsala, Sweden
| | - M Horanyi
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - A Collette
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
| | - R Yelle
- Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
| | - B M Jakosky
- Laboratory for Atmospheric and Space Physics, University of Colorado-Boulder, Boulder, CO 80303, USA
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6
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Abstract
Spectroscopy of Io's Pele plume against Jupiter by the Hubble Space Telescope in October 1999 revealed absorption due to S2 gas, with a column density of 1.0 +/- 0.2 x 10(16) per square centimeter, and probably also SO(2) gas with a column density of 7 +/- 3 x 10(16) per square centimeter. This SO2/S2 ratio (3 to 12) is expected from equilibration with silicate magmas near the quartz-fayalite-magnetite or wüstite-magnetite buffers. Condensed S3 and S4, probable coloring agents in Pele's red plume deposits, may form by polymerization of the S2, which is unstable to ultraviolet photolysis. Diffuse red deposits near other Io volcanoes suggest that venting and polymerization of S2 gas is a widespread feature of Io volcanism.
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Affiliation(s)
- J R Spencer
- Lowell Observatory, 1400 West Mars Hill Road, Flagstaff, AZ 86001, USA.
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