title: Mars atmosphere. The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars.
abstract: The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. paul.r.mahaffy@nasa.gov.
authors.forename: P R
authors.initials: PR
authors.lastname: Mahaffy
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors.forename: C R
authors.initials: CR
authors.lastname: Webster
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Stern
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85281, USA. Center for Research and Exploration in Space Science and Technology, University of Maryland College Park, College Park, MD 20742, USA.
authors.forename: A E
authors.initials: AE
authors.lastname: Brunner
authors.affiliation: Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109-2143, USA.
authors.forename: S K
authors.initials: SK
authors.lastname: Atreya
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: P G
authors.initials: PG
authors.lastname: Conrad
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: S
authors.initials: S
authors.lastname: Domagal-Goldman
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Eigenbrode
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors.forename: G J
authors.initials: GJ
authors.lastname: Flesch
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors.forename: L E
authors.initials: LE
authors.lastname: Christensen
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Center for Research and Exploration in Space Science and Technology, University of Maryland College Park, College Park, MD 20742, USA.
authors.forename: H B
authors.initials: HB
authors.lastname: Franz
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. NASA Postdoctoral Program, Oak Ridge Associated Universities, Oak Ridge, TN 37831, USA.
authors.forename: C
authors.initials: C
authors.lastname: Freissinet
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Glavin
authors.affiliation: Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA.
authors.forename: J P
authors.initials: JP
authors.lastname: Grotzinger
authors.affiliation: NASA Johnson Space Flight Center, Houston, TX 77058, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Jones
authors.affiliation: Office of the President, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
authors.forename: L A
authors.initials: LA
authors.lastname: Leshin
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA. Goddard Earth Sciences Technology and Research (GESTAR)/Universities Space Research Association (USRA) NASA Goddard Space Flight Center Greenbelt, MD 20771, USA.
authors.forename: C
authors.initials: C
authors.lastname: Malespin
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: A C
authors.initials: AC
authors.lastname: McAdam
authors.affiliation: NASA Johnson Space Flight Center, Houston, TX 77058, USA.
authors.forename: D W
authors.initials: DW
authors.lastname: Ming
authors.affiliation: Universidad Nacional Autónoma de México, Ciudad Universitaria, México D.F. 04510, Mexico.
authors.forename: R
authors.initials: R
authors.lastname: Navarro-Gonzalez
authors.affiliation: NASA Johnson Space Flight Center, Houston, TX 77058, USA.
authors.forename: P B
authors.initials: PB
authors.lastname: Niles
authors.affiliation: Institute for Astronomy, University of Hawaii, Honolulu, HI 96822, USA.
authors.forename: T
authors.initials: T
authors.lastname: Owen
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: A A
authors.initials: AA
authors.lastname: Pavlov
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, USA.
authors.forename: A
authors.initials: A
authors.lastname: Steele
authors.affiliation: Planetary Environments Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Trainer
authors.affiliation: Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
authors.forename: K H
authors.initials: KH
authors.lastname: Williford
authors.affiliation: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
authors.forename: J J
authors.initials: JJ
authors.lastname: Wray