A SPECTROPHOTOMETRIC STUDY OF COMET DUST: WINDOWS INTO THE EARLY SOLAR SYSTEM

OVERVIEW: COMETS FORM OUR MOST DIRECT LINK TO THE EARLIEST STAGES OF THE FORMATION AND EVOLUTION OF THE SOLAR SYSTEM. THE ABUNDANCES AND SPATIAL DISTRIBUTION OF MAJOR GAS SPECIES (H2O CO2 CO) AND THE MAJOR DUST SPECIES (SILICATE AND CARBONACEOUS) IN COMET COMAE PROVIDE DIRECT INSIGHT INTO THE CHEMISTRY AND INTERNAL COMPOSITION OF PRIMITIVE BODIES. COMETS AND ASTEROIDS DELIVERED THESE MATERIALS AND PRE-BIOTIC PRECURSORS TO THE TERRESTRIAL PLANET ZONE DURING THE PERIOD OF HEAVY BOMBARDMENT POTENTIALLY CATALYZING LIFE. EVALUATING THE CHARACTERISTICS OF REFRACTORY MATERIALS ICES AND VOLATILES OF COMETS ENHANCES UNDERSTANDING OF THE ORIGIN AND EVOLUTION OF OUR SOLAR SYSTEM AND THE POTENTIAL FOR LIFE ELSEWHERE. PROCESSES THAT OCCURRED IN OUR PROTOPLANETARY DISK MUST BE TAKING PLACE AT SOME LEVEL IN THE YOUNGEST OF THESE EXOPLANETARY SYSTEMS ALTHOUGH THE DETAILS WILL DIFFER. THE NARRATIVE TALE GLEANED THROUGH THE STUDY OF COMETS IS AN ACCOUNT OF OUR ORIGINS.