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The precipitation of keV energetic oxygen ions at Mars and their effects during the comet Siding Spring approach
Author(s) -
Gronoff Guillaume,
Rahmati Ali,
Wedlund Cyril Simon,
Mertens Christopher J.,
Cravens Thomas E.,
Kallio Esa
Publication year - 2014
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 - 10.1002/2014gl060902
Subject(s) - comet , atmosphere of mars , mars exploration program , atmosphere (unit) , atmospheric sciences , martian , physics , solar wind , ionosphere , ionization , meteoroid , flux (metallurgy) , electron precipitation , astrobiology , solar energetic particles , ion , environmental science , astronomy , coronal mass ejection , meteorology , plasma , magnetosphere , materials science , nuclear physics , quantum mechanics , metallurgy
Comet Siding Spring C/2013 A1 will pass Mars on 19 October 2014, entailing particle and dust precipitation in the Martian upper atmosphere and a potential dust hazard for orbiters. An estimate of the flux of energetic O + ions picked up by the solar wind from the cometary coma is shown, with an increase of the O + flux above 50 keV by 2 orders of magnitude. While the ionization of Mars' upper atmosphere by precipitating O + ions is expected to be negligible compared to solar EUV‐XUV ionization, it is of the same order of magnitude at 110 km altitude during the cometary passage, leading to detectable increases in ionospheric densities. Cometary O + pickup ion precipitation is expected to be the major nightside ionization source, creating a temporary ionosphere and a global airglow. These effects are dependent on the solar and cometary activities at the time of the encounter.