Primordial argon isotope fractionation in the atmosphere of Mars measured by the SAM instrument on Curiosity and implications for atmospheric loss. Issue 21 (6th November 2013)

• Record Type: Journal Article
• Authors: Atreya, Sushil K.; Trainer, Melissa G.; Franz, Heather B.; Wong, Michael H.; Manning, Heidi L. K.; Malespin, Charles A.; Mahaffy, Paul R.; Conrad, Pamela G.; Brunner, Anna E.; Leshin, Laurie A.; Jones, John H.; Webster, Christopher R.; Owen, Tobias C.; Pepin, Robert O.; Navarro‐González, R.
• Is Part Of: Geophysical research letters. Volume 40:Issue 21(2013:Nov.)
• Page Start: 5605
• Page End: 5609
• Publication Date: 2013-11-06
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2013GL057763
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>[1] The quadrupole mass spectrometer of the Sample Analysis at Mars (SAM) instrument on <italic>Curiosity</italic> rover has made the first high‐precision measurement of the nonradiogenic argon isotope ratio in the atmosphere of Mars. The resulting value of ³⁶Ar/³⁸Ar = 4.2 ± 0.1 is highly significant for it provides excellent evidence that "Mars" meteorites are indeed of Martian origin, and it points to a significant loss of argon of at least 50% and perhaps as high as 85–95% from the atmosphere of Mars in the past 4 billion years. Taken together with the isotopic fractionations in N, C, H, and O measured by SAM, these results imply a substantial loss of atmosphere from Mars in the posthydrodynamic escape phase.</p> </abstract>