The study of exospheres can help us understand the long-term loss of volatiles from planetary bodies due to interactions of planets, satellites, and small bodies with the interplanetary medium, solar radiation, and internal forces including diffusion and outgassing. Recent evidence for water and OH on the Moon has spurred interest in processes involving chemistry and sequestration of volatile species at the poles and in voids. In recent years, NASA has sent spacecraft to asteroids including Vesta and Ceres, and ESA sent Rosetta to comet 67P/Churyumov–Gerasimenko and the asteroids Lutetia and Steins. Japan's Hayabusa spacecraft returned a sample from asteroid Itakowa, and OSIRIS-REX will return a sample from a primitive asteroid, Bennu, to Earth. In a surface-bounded exosphere, the gases are derived from the surface and thus reflect the composition of the body's regolith, although not in a one-to-one ratio. Observation of an escaping exosphere, termed a corona, is challenging. We have therefore embarked on a parametrical study of exospheres as a function of mass of the exospheric species, mass of the primary body and source velocity distribution, specifically thermal (Maxwell-Boltzmann) and sputtering. The goal is to provide a quick look to determine under what conditions and for what mass of the primary body the species of interest are expected to be bound or escaping and to quickly estimate the observability of exospheric species. This work does not provide a comprehensive model but rather serves as a starting point for further study. These parameters will be useful for mission planning as well as for students beginning a study of planetary exospheres.


    Access

    Access via TIB

    Check availability in my library


    Export, share and cite



    Title :

    Exospheric Escape: A Parametrical Study


    Contributors:

    Published in:

    Publication date :

    2017-06-27



    Type of media :

    Miscellaneous


    Type of material :

    No indication


    Language :

    English




    Exospheric Escape: A Parametrical Study

    Killen, Rosemary M. / Burger, Matthew H. / Farrell, William M. | NTRS | 2017


    Exospheric escape: A parametrical study

    Rosemary M Killen / Matthew H Burger / William M Farrell | NTRS | 2017



    Exospheric temperatures during solar cycle 22

    Badhwar, Gautam D. | NTRS | 1990


    On the Exospheric Temperature of Venus

    S. H. Gross / W. E. Mc Govern / S. I. Rasool | NTIS | 1967