Source of Acquisition NASA Goddard Space Flight Center z MESSENGER: Exploring Mercury's Magnetosphere James A. Slavin', Stamatios M. Krimigis2, Mario H. Acuiia', Brian J. Anderson2, Daniel N. Baker3, Patrick L. Koehn4, Haje Korth2, Stefan0 Livi2,Barry H. Mad2, Sean C. Solomon', and Thomas H. Zurbuchen4 'Laboratory for Solar and Space Physics, Goddard Space Flight Center, Greenbelt, MD 20771 Johns Hopkins Laboratory, Applied Physics Laboratory, Laurel, MD 20723 Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80303 Oceanic and Space Sciences Department, University of Michigan, Atmospheric, Ann Arbor, MI 48109 Department of Terrestrial Magnetism, Camegie Institution of Washington, Washington, DC 20015 Submitted to zyxwvutsrq Space Science Reviews, 2005 Dec 19,2005 Draft zyxwvuts , 1