title: Isotopes of nitrogen on Mars: Atmospheric measurements by Curiosity's mass spectrometer.
abstract: [1] The Sample Analysis at Mars (SAM) instrument suite on the Mars Science Laboratory (MSL) measured a Mars atmospheric14N/15N ratio of 173 ± 11 on sol 341 of the mission, agreeing with Viking's measurement of 168 ± 17. The MSL/SAM value was based on Quadrupole Mass Spectrometer measurements of an enriched atmospheric sample, with CO2and H2O removed. Doubly ionized nitrogen data at m/z 14 and 14.5 had the highest signal/background ratio, with results confirmed by m/z 28 and 29 data. Gases in SNC meteorite glasses have been interpreted as mixtures containing a Martian atmospheric component, based partly on distinctive14N/15N and40Ar/14N ratios. Recent MSL/SAM measurements of the40Ar/14N ratio (0.51 ± 0.01) are incompatible with the Viking ratio (0.35 ± 0.08). The meteorite mixing line is more consistent with the atmospheric composition measured by Viking than by MSL.
authors.affiliation: Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan Ann Arbor, Michigan, USA ; Astronomy Department, University of California Berkeley, California, USA.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Wong
authors.affiliation: Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan Ann Arbor, Michigan, USA.
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Atreya
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Paul N
authors.initials: PN
authors.lastname: Mahaffy
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Heather B
authors.initials: HB
authors.lastname: Franz
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Malespin
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Melissa G
authors.initials: MG
authors.lastname: Trainer
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Jennifer C
authors.initials: JC
authors.lastname: Stern
authors.affiliation: Code 699, NASA Goddard Space Flight Center Greenbelt, Maryland, USA.
authors.forename: Pamela G
authors.initials: PG
authors.lastname: Conrad
authors.affiliation: Department of Physics, Concordia College Moorhead, Minnesota, USA.
authors.forename: Heidi L K
authors.initials: HL
authors.lastname: Manning
authors.affiliation: School of Physics and Astronomy, University of Minnesota Minneapolis, Minnesota, USA.
authors.forename: Robert O
authors.initials: RO
authors.lastname: Pepin
authors.affiliation: School of Physics and Astronomy, University of Minnesota Minneapolis, Minnesota, USA.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Becker
authors.affiliation: NASA Ames Research Center Moffet Field, California, USA.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: McKay
authors.affiliation: Institute for Astronomy, University of Hawai'i at Mānoa Honolulu, Hawaii, USA.
authors.forename: Tobias C
authors.initials: TC
authors.lastname: Owen
authors.affiliation: Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México México City, México.
authors.forename: Rafael
authors.initials: R
authors.lastname: Navarro-González
authors.affiliation: NASA Johnson Space Center Houston, Texas, USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Jones
authors.affiliation: LASP, University of Colorado Boulder Colorado, USA.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Jakosky
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington Washington, District of Columbia, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Steele