SEVERAL PROPERTIES OF THE SOLAR SYSTEM INCLUDING THE WIDE RADIAL SPACING AND ORBITAL ECCENTRICITIES OF THE GIANT PLANETS CAN BE EXPLAINED IF THE EARLY SOLAR SYSTEM EVOLVED THROUGH A DYNAMICAL INSTABILITY FOLLOWED BY MIGRATION OF PLANETS IN THE PLANETESIMAL DISK. RECENTLY WE DEVELOPED THE LATEST GENERATION OF INSTABILITY/MIGRATION MODELS WHOSE INITIAL CONDITIONS ARE TIGHTLY LINKED TO OUR EXPECTATIONS FOR PLANET FORMATION IN THE PROTOPLANETARY NEBULA. THESE MODELS WERE SUBSEQUENTLY USED TO BETTER UNDERSTAND THE DYNAMICAL ORIGIN OF THE KUIPER BELT JUPITER TROJANS AND IRREGULAR SATELLITES. HERE WE PROPOSE TO CONTINUE THESE STUDIES WITH AN EYE TO DETERMINING HOW THE INSTABILITY/MIGRATION MODELS CAN BE CONSTRAINED FROM THE PRESENT SOLAR SYSTEM ARCHITECTURE. SPECIFICALLY WE PROPOSE TO STUDY THE FOLLOWING TWO THEMES: THEME 1: THE DYNAMICAL STRUCTURE OF THE KUIPER BELT IS A BLUEPRINT OF NEPTUNE'S ORBITAL HISTORY. MUCH OF THIS STRUCTURE CAN BE EXPLAINED IF NEPTUNE MIGRATED SMOOTHLY OR NOT OVER SEVERAL AU AND/OR IF NEPTUNE WAS SCATTERED TO AN ECCENTRIC ORBIT DURING PLANETARY INSTABILITY. THESE PROCESSES AND THEIR TIMESCALES ARE KEY TO OUR UNDERSTANDING OF THE KUIPER BELT. HERE WE PROPOSE TO STUDY THE DYNAMICS OF THE KUIPER BELT WITH THE AIM OF CONSTRAINING NEPTUNE'S MIGRATION AND THE DYNAMICAL STATE OF THE ORIGINAL PLANETESIMAL DISK. PARTICULAR ATTENTION WILL BE GIVEN TO THE ORIGIN OF THE SCATTERED DISK. WE WILL ALSO TEST THE 5TH GIANT PLANET HYPOTHESIS. THEME 2: IT HAS BEEN RECENTLY PROPOSED THAT THE ORBITAL ALIGNMENT OF DISTANT TRANS-NEPTUNIAN OBJECTS (TNOS) CAN BE INTERPRETED AS A GRAVITATIONAL SIGNATURE OF AN UNSEEN DISTANT PLANET IN THE SOLAR SYSTEM (HEREAFTER PLANET NINE). THE STUDIES TENTATIVELY SUGGESTED PLANET'S MASS ~10 EARTH MASSES A LARGE ORBIT (SEMIMAJOR AXIS A~700 AU) AND SIGNIFICANT ECCENTRICITY (E~0.6). ADDITIONAL CONSTRAINTS ON PLANET NINE WERE OBTAINED FROM THE CASSINI RADIO RANGING DATA. THE OBSERVATIONAL DETECTION OF PLANET NINE IS CHALLENGING BECAUSE THE EXISTING RESULTS DO NOT CONFINE PLANET NINE'S EXPECTED POSITION ON THE SKY SUFFICIENTLY WELL. HERE WE PROPOSE TO INVESTIGATE WHETHER THE PROPERTIES OF PLANET NINE CAN BE BETTER CONSTRAINED FROM ITS GRAVITATIONAL INFLUENCE ON DISTANT TNOS. WE WILL ALSO INCLUDE PLANET NINE IN A FORMATION MODEL TO UNDERSTAND HOW THE HYPOTHESIZED PLANET WOULD ACT DURING KUIPER BELT FORMATION AND WHETHER IT COULD HELP TO EXPLAIN THE HIGHLY INCLINED ORBITS OF SOME TNOS. RELEVANCE THE PROPOSED RESEARCH IS FUNDAMENTAL TO UNDERSTANDING THE FORMATION AND EARLY EVOLUTION OF THE SOLAR SYSTEM. THIS IS A CENTRAL THEME OF NASA'S STRATEGIC GOALS AND THE EMERGING WORLDS PROGRAM. SPECIFICALLY THE NRA FOR THE EMERGING WORLDS PROGRAM STATES THAT THE PROGRAM ``AIMS TO ANSWER THE FUNDAMENTAL SCIENCE QUESTION OF HOW THE SOLAR SYSTEM FORMED AND EVOLVED'' AND THAT THE PROGRAM OBJECTIVES INCLUDE ``FORMATION ACCRETION AND STABILITY OF SOLAR SYSTEM BODIES'' AND ``EARLY DYNAMICAL EVOLUTION OF THE SOLAR SYSTEM''. THE TYPES OF STUDIES THAT ARE SUPPORTED INCLUDE ``THEORETICAL INVESTIGATIONS''. HERE WE PROPOSE THEORETICAL INVESTIGATIONS OF THE FORMATION AND EARLY DYNAMICAL EVOLUTION OF THE KUIPER BELT AND THE PLANET NINE HYPOTHESIS. BOTH THESE THEMES ARE DIRECTLY RELEVANT TO THE NASA STRATEGIC GOALS AND RESEARCH OBJECTIVES AND TO THE EMERGING WORLDS PROGRAM IN PARTICULAR. OUR GOAL IS TO CONSTRAIN PLANETARY FORMATION PROCESSES AND THE EVENTS THAT HAVE TAKEN PLACE IN THE SOLAR SYSTEM OVER ITS HISTORY.