THE IMPORTANCE OF STUDYING WATER AND ORGANIC MOLECULES IS RELATED TO THEIR BIOLOGICAL RELEVANCE. THE ORIGIN OF WATER OCEANS AND PRE-BIOTIC ORGANIC MOLECULES ON EARTH AND THE ORIGIN OF AN ANCIENT OCEAN ON MARS1 IS UNSOLVED. THE TERRESTRIAL PLANETS FORMED IN A DRY REGION OF THE PROTO-PLANETARY DISK BY AGGREGATION OF ROCKY PLANETESIMALS; ICY AGGREGATES COULD FORM ONLY BEYOND THE FROST LINES. EVEN TODAY THE BULK EARTH IS COSMICALLY DRY (POOR IN HYDROGEN RELATIVE TO THE PROTOPLANETARY DISK). ABOUT 60 MA AFTER EARTH-ACCRETION THE MOON-FORMING IMPACT PROBABLY REMOVED ANY WATER THAT MAY HAVE OUTGASSED AFTER CORE FORMATION LEAVING THE HADEAN EARTH WATER-POOR AT ITS SURFACE. YET EARLY ZIRCONS PROVIDE EVIDENCE THAT OCEANS EXISTED BY 250 MA AFTER EARTH S FORMATION. HOW DID TERRESTRIAL PLANETS ACQUIRE THEIR WATER? BOMBARDMENT OF EARTH AND MARS BY ICY AND ROCKY PLANETESIMALS (REPRESENTED TODAY BY COMET NUCLEI AND ASTEROIDS) WAS COMMON FROM THEIR FORMATION THROUGH THE LATE HEAVY BOMBARDMENT2-7. BECAUSE WATER IS THE MOST ABUNDANT NATIVE ICE IN COMETARY NUCLEI WITH THE AGGREGATE CHON ICES COMPRISING A CLOSE SECOND WE WANT TO UNDERSTAND THE ROLE PRIMITIVE BODIES PLAYED IN DELIVERING WATER AND PRE-BIOTIC ORGANICS TO THE YOUNG INNER PLANETS8-10. INVESTIGATIONS OF COSMOGONIC INDICATORS ARE NECESSARY TO TEST THE HYPOTHESIS THAT SMALL ICY BODIES DELIVERED WATER AND PREBIOTIC ORGANICS TO EARLY EARTH AND MARS. ISOTOPIC RATIOS (E.G. WATER D/H 13/C12C 15N/14N) NUCLEAR SPIN TEMPERATURES AND CHEMICAL ABUNDANCES IN COMETS ARE KEY TO IDENTIFYING TEMPERATURES MOLECULAR ABUNDANCES AND PHYSICAL PROCESSES THAT OCCURRED 4.6 BILLION YEARS AGO IN THE COMET-FORMING REGIONS OF THE PROTO-PLANETARY DISK. OBSERVATIONS OF MARS WILL PROVIDE NEW DATA ON THE COMPOSITION GLOBAL DISTRIBUTION AND VARIABILITY OF CO2 AND TRACE GASES INCLUDING ISOTOPOLOGS. TOGETHER THE INTER-COMPARISON OF COSMOGONIC INDICATORS IN COMETS AND IN PLANETARY ATMOSPHERES THROUGH HIGH-RESOLUTION SPECTROSCOPIC STUDIES WILL ADDRESS THESE UNRESOLVED QUESTIONS.