Observations of metallic species in Mercury's exosphere

    Authors

    R. M. Killen; A. E. Potter; R. J. Vervack; E. T. Bradley; W. E. McClintock; C. M. Anderson;M. H. Burger

    Comments

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    Abbreviated Journal Title

    Icarus

    Keywords

    Mercury, Atmosphere; Mercury, Surface; STIMULATED DESORPTION; ATMOSPHERE; POTASSIUM; SODIUM; IONS; MOON; DISCOVERY; SURFACE; IMPACT; NA; Astronomy & Astrophysics

    Abstract

    From observations of the metallic species sodium (Na), potassium (K). and magnesium (Mg) in Mercury's exosphere, we derive implications for source and loss processes All metallic species observed exhibit a distribution and/or line width characteristic of high to extreme temperature - tens of thousands of degrees K The temperatures of refractory species, Including magnesium and calcium, indicate that the source process for the atoms observed in the tail and near-planet exosphere are consistent with ion sputtering and/or impact vaporization of a molecule with subsequent dissociation into the atomic form The extended Mg tall is consistent with a surface abundance of 5-8% Mg by number. if 30% of impact-vaporized Mg remains as MgO and half of the impact vapor condenses Globally, ion sputtering is not a major source of Mg, but locally the sputtered source can be larger than the impact vapor source We conclude that the Na and K in Mercury's exosphere can be derived from a regolith composition similar to that of Luna 16 soil (or Apollo 17 orange glass), in which the abundance by number is 0 0027 (0 0028) for Na and 0 0006 (0 0045) for K (C) Published by Elsevier Inc

    Journal Title

    Icarus

    Volume

    209

    Issue/Number

    1

    Publication Date

    1-1-2010

    Document Type

    Article

    Language

    English

    First Page

    75

    Last Page

    87

    WOS Identifier

    WOS:000281687800009

    ISSN

    0019-1035

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