A MULTIDISCIPLINARY APPROACH TO UNRAVEL PHOTON AND ELECTRON PROCESSES AND THEIR INTERACTION WITH THE COMA OF 67P/CHURYUMOV- GERASIMENKO SCIENCE GOALS THE OBJECTIVE OF THIS PROPOSAL IS TO CONDUCT A MULTI-INSTRUMENT ANALYSIS OF ROSETTA OBSERVATIONS THAT WILL UNTANGLE THE DIFFERING EFFECTS OF PHOTON AND ELECTRON PROCESSES. AURORAL EMISSION FROM ELECTRON IMPACT PROCESSES CAN PROVIDE A REMOTE WINDOW ON THE PHYSICAL PROPERTIES OF PLASMA AND NEUTRAL GASES SURROUNDING SMALL BODIES (GALAND&CHAKRABARTI 2002; ROTH ET AL. 2014). SURPRISINGLY ROSETTA FOUND THAT OUTSIDE 2 AU PRE-PERIHELION ATOMIC AND MOLECULAR EMISSION FEATURES IN THE INNER COMA WERE PREDOMINANTLY CAUSED BY DISSOCIATIVE ELECTRON IMPACT EXCITATION (FELDMAN ET AL. 2015). WHEN THE COMET CAME WITHIN 2 AU OF THE SUN FLUORESCENT EMISSION BECAME THE DOMINANT PROCESS AS WATER DENSITIES IN THE INNER COMA COULD EFFECTIVELY COOL THE ELECTRON POPULATION BELOW THE THRESHOLD ENERGY OF THE RELEVANT ELECTRON IMPACT DISSOCIATIVE EXCITATION PROCESSES (BODEWITS ET AL. 2016). THE COMET WAS ALSO SUBJECTED TO SOLAR TRANSIENT EVENTS THAT INCREASED ATOMIC EMISSION FEATURES A PROCESS WITH IMPLICATIONS ON THE CHEMISTRY AND PHYSICAL PROPERTIES OF THE COMA THAT ARE NOT YET FULLY UNDERSTOOD (EDBERG ET AL. 2016 NOONAN ET AL. 2018). FURTHER QUANTITATIVE INTERPRETATION OF THE ALICE AND OSIRIS IMAGES OF THE COMA HAS BEEN HAMPERED BY LIMITED LABORATORY MEASUREMENTS OF EXCITATION CROSS SECTIONS FOR ELECTRON IMPACT REACTIONS WITH THE GASES PRESENT IN COMETARY COMAE. TO BETTER UNDERSTAND THE MORPHOLOGY OF THE EMISSION OBSERVED BY ALICE AND OSIRIS IT IS NECESSARY TO CORRELATE THE DISTRIBUTION OF THE NEUTRAL GAS AND ELECTRONS IN THE COMA. METHODOLOGY WE WILL COMBINE AND CORRELATE IN-SITU MEASUREMENTS OF THE CHARACTERISTICS OF THE ELECTRON POPULATION BY THE RPC INSTRUMENTS WITH THE TEMPERATURES OF WATER WITH DETAILED EMISSION MAPS OF FRAGMENT SPECIES (OH OH+ OI CI ..) ACQUIRED BY ALICE AND OSIRIS. WHEN THE COMET APPROACHED THE SUN ITS PRODUCTION RATES (AND THUS LOCAL DENSITIES OF SPECIES) INCREASED BY TWO ORDERS OF MAGNITUDES PROVIDING US WITH A WIDE SAMPLE OF PHYSICAL ENVIRONMENTS. FURTHERMORE THE COMA EXPERIENCED MULTIPLE SHORT-LIVED EVENTS THAT PROVIDE NATURAL LABORATORIES TO STUDY PHYSICAL AND CHEMICAL PROCESSES IN THE COMA SUCH AS COMET OUTBURSTS (TEMPORAL ENHANCEMENT OF LOCAL DENSITY) CORONAL MASS EJECTIONS AND CO-ROTATING INTERACTION REGIONS (SOLAR WIND INTENSITY ELECTRON DENSITY AND TEMPERATURE INCREASE) AND SOLAR FLARES (INCREASED HIGH ENERGY EMISSION FROM THE SUN). WE WILL USE THESE EVENTS AS NATURAL LABORATORIES TO STUDY HOW PHYSICAL PROPERTIES AFFECT THE COMPOSITION AND CHEMISTRY IN THE COMA. FINALLY TO UNDERSTAND HOW THE EMISSION OF FRAGMENT SPECIES SEEN BY OSIRIS AND ALICE ARE RELATED TO THE PARENT MOLECULES (AS SEEN BY MIRO) WE WILL CONTINUE TO CONDUCT ELECTRON IMPACT EXPERIMENTS ON ABUNDANT COMA MOLECULES SUCH AS H2O CO2 O2 AND CO IN THE LAB. RELEVANCE OUR PROPOSAL IS DIRECTLY RELEVANT TO THE RDAP PROGRAM AS WE WILL ENHANCE THE SCIENTIFIC RETURN OF ROSETTA MISSION BY PLACING SEVERAL INSTRUMENTS OBSERVATIONS AND DATASETS (MEASURED BRIGHTNESSES ENERGY DISTRIBUTIONS AND DENSITIES) INTO CONTEXT WITH IDENTIFIED COMA PROCESSES. THE DIRECT COMBINATION OF THE RESULTS OF 4 INSTRUMENTS ON BOARD ROSETTA GOES ABOVE AND BEYOND PREVIOUSLY FUNDED EFFORTS WHICH PRIMARILY FOCUSED ON PLANNING ACQUISITION ARCHIVING AND PRELIMINARY DATA ANALYSIS. THIS PROJECT WILL ALLOW US TO PLACE ROSETTA RESULTS INTO THE CONTEXT OF THE LARGER BODY OF COMETS THAT CAN BE STUDIED FROM EARTH. ALL THESE PROPOSED ANALYSES CAN AND WILL BE ACCOMPLISHED WITH THE DATA AVAILABLE IN THE PDS.