The precipitation of keV energetic oxygen ions at Mars and their effects during the comet Siding Spring approach. Issue 14 (28th July 2014)

• Record Type: Journal Article
• Authors: Gronoff, Guillaume; Rahmati, Ali; Wedlund, Cyril Simon; Mertens, Christopher J.; Cravens, Thomas E.; Kallio, Esa
• Is Part Of: Geophysical research letters. Volume 41:Issue 14(2014:Jul.)
• Page Start: 4844
• Page End: 4850
• Publication Date: 2014-07-28
• Subjects: Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2014GL060902
• Languages: English
• ISSNs: 0094-8276

Abstract

<abstract abstract-type="main" id="grl51915-abs-0001"> <title>Abstract</title> <p id="grl51915-para-0001">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.</p> </abstract>