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Mars heavy ion precipitating flux as measured by Mars Atmosphere and Volatile EvolutioN
Author(s) -
Leblanc F.,
Modolo R.,
Curry S.,
Luhmann J.,
Lillis R.,
Chaufray J. Y.,
Hara T.,
McFadden J.,
Halekas J.,
Eparvier F.,
Larson D.,
Connerney J.,
Jakosky B.
Publication year - 2015
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2015gl066170
Subject(s) - mars exploration program , atmosphere of mars , solar wind , atmosphere (unit) , sputtering , astrobiology , atmospheric escape , flux (metallurgy) , exosphere , ion , population , atmospheric sciences , polar wind , precipitation , physics , gyroradius , martian , environmental science , plasma , materials science , magnetopause , meteorology , nuclear physics , thin film , demography , quantum mechanics , sociology , metallurgy
In the absence of an intrinsic dipole magnetic field, Mars' O + planetary ions are accelerated by the solar wind. Because of their large gyroradius, a population of these planetary ions can precipitate back into Mars' upper atmosphere with enough energy to eject neutrals into space via collision. This process, referred to as sputtering, may have been a dominant atmospheric loss process during earlier stages of our Sun. Yet until now, a limited number of observations have been possible; Analyzer of Space Plasmas and Energetic Atoms‐3/Mars Express observed such a precipitation only during extreme conditions, suggesting that sputtering might be not as intense as theoretically predicted. Here we describe one example of precipitation of heavy ions during quiet solar conditions. Between November 2014 and April 2015, the average precipitating flux is significant and in agreement with predictions. From these measured precipitating fluxes, we estimate that a maximum of 1.0 × 10 24 O/s could have been lost due to sputtering.