THE PROPOSED WORK WILL COMBINE MESSENGER (MERCURY SURFACE SPACE ENVIRONMENT GEOCHEMISTRY AND RANGING) DATA OF THE EXOSPHERE AND PLASMA ENVIRONMENT WITH MODELS OF THE INTERPLANETARY DUST ENVIRONMENT AND EXOSPHERE TO BETTER QUANTIFY THE ROLE OF EXOSPHERE DRIVERS SUCH AS THE SOLAR WIND AND METEOROID PARTICLES. SPECIFICALLY IN THIS PROPOSAL WE WILL BUILD UPON PREVIOUS WORK (CASSIDY ET AL. 2014; 2016; BURGER ET AL. 2012; 2014; MERKEL ET AL. 2017) AS WE TRY TO UNDERSTAND FOUR OUTSTANDING QUESTIONS: 1) HOW ARE THE DIFFERENCES BETWEEN MG AND CA IN MERCURY S EXOSPHERE GOVERNED BY METEOROID IMPACT VELOCITIES? 2) WHY IS THE NA ATMOSPHERE DIFFERENT BETWEEN THE TWO LEGS AND WHY DOES ITS PEAK FOLLOW THE COLD POLES (LONGITUDES OF 90 AND 270 )? 3) WHAT DOES THE POLAR ATMOSPHERE TELL US ABOUT PRECIPITATING SOLAR WIND IONS AND COMPOSITIONAL VARIATION? AND 4) GIVEN THAT MG AND CA EVIDENTLY RESPOND TO IMPACTS CAN WE USE MERCURY'S ATMOSPHERE AS A SENSITIVE WAY TO PROBE METEOROID POPULATIONS IN THE INNER SOLAR SYSTEM?