OBJECTIVES: THE AIM OF THIS PROPOSAL IS TO UNDERSTAND THE PROCESSES SURROUNDING THE GENERATION OF THE ANCIENT LUNAR DYNAMO. OUR MAJOR GOAL IS TO DETERMINE WHETHER MECHANICAL DRIVING DUE TO A PRECESSING MANTLE POSSIBLY IN COMBINATION WITH CONVECTION CAN EXPLAIN THE PALEOMAGNETIC RECORD. WE WILL ALSO DETERMINE THE IMPLICATIONS FOR INVESTIGATIONS OF LUNAR PALEOMAGNETIC POLES AND TRUE POLAR WANDER (TPW).METHODS: THIS STUDY WILL INVOLVE THREE TASKS TO INVESTIGATE THE DYNAMICS AND CONSEQUENCES OF A MANTLE-PRECESSION DRIVEN LUNAR DYNAMO: TASK 1: INVESTIGATIONS OF LUNAR DYNAMO MODELS DRIVEN ONLY BY MANTLE PRECESSION: THIS TASK WILL INVOLVE MODIFYING NUMERICAL DYNAMO CODES TO INCLUDE EFFECTS OF MANTLE PRECESSION AND CARRY OUT SUITES OF DYNAMO SIMULATIONS IN ORDER TO UNDERSTAND THE DYNAMICS OF MANTLE PRECESSION DRIVEN DYNAMOS. WE WILL THEN DEVELOP SCALING STUDIES FOR THE LUNAR MAGNETIC FIELD STRENGTH AND COMPARE OUR RESULTS TO THE LUNAR PALEOMAGNETIC RECORD. TASK 2: INVESTIGATIONS OF LUNAR DYNAMO MODELS DRIVEN BY A COMBINATION OF MANTLE PRECESSION AND CONVECTION: THIS TASK WILL INVOLVE COMBINING THE MANTLE-PRECESSION DRIVING DEVELOPED IN TASK 1 WITH STANDARD CONVECTIVE DRIVING IN A SUITE OF DYNAMO SIMULATIONS IN ORDER TO UNDERSTAND THE COMBINED DYNAMICS AND IMPLICATIONS FOR THE LUNAR DYNAMO. TASK 3: INVESTIGATIONS OF THE IMPLICATIONS OF THESE DYNAMO MODEL RESULTS FOR LUNAR PALEOPOLE STUDIES: IN THIS TASK WE WILL USE INFORMATION FROM THE DYNAMOS MODELS IN TASKS 1 AND 2 TO DETERMINE IF STANDARD PALEOPOLE CALCULATION TECHNIQUES THAT INVOLVE USING THE GEOCENTRICAXIAL- DIPOLE (GAD) HYPOTHESIS PRODUCE BIASES IN PALEOPOLE STUDIES FOR THE MOON. PERCEIVED SIGNIFICANCE/RELEVANCE TO NASA: THIS WORK WILL PROVIDE FUNDAMENTAL UNDERSTANDING OF THE LUNAR DYNAMO MECHANISM THAT PRODUCED THE LUNAR CRUSTAL REMANENT MAGNETIC FIELD. THIS IS IMPORTANT BECAUSE THE STRENGTH MORPHOLOGY AND STABILITY OF THE LUNAR SURFACE PALEOMAGNETIC FIELD IS NEEDED TO CONSTRAIN PROPERTIES OF THE MAGNETIZED CRUST SUCH AS THE THICKNESS AND MAGNETIC SUSCEPTIBILITY OF THE MAGNETIZED LAYER. THE MORPHOLOGY AND STABILITY OF THE LUNAR DYNAMO WILL ALSO AID STUDIES OF LUNAR PALEOPOLES IN DETERMINING WHETHER THE GEOCENTRIC AXIAL DIPOLE (GAD) HYPOTHESIS IS REASONABLE FOR PALEOMAGNETIC POLE STUDIES THAT ARE USED TO DETERMINE TPW ON THE MOON. IN ADDITION THE INVESTIGATION OF MECHANICAL DRIVING AND THE COMBINATION WITH CONVECTIVE DRIVING COULD HAVE POTENTIAL APPLICATIONS TO OTHER PLANETARY DYNAMOS. THIS STUDY IS RELEVANT TO NASA'S INTERESTS AND PROGRAMS SINCE IT INVOLVES INVESTIGATIONS OF PLANETARY INTERIORS AND NUMERICAL MODELING OF PHYSICAL PLANETARY PROCESSES. IN PARTICULAR THIS PROPOSAL IS RESPONSIVE TO THE "INTERIOR STRUCTURE" AND "PLANETARY MAGNETISM" CATEGORIES OF THE "SURFACES AND INTERIORS" ITEM ON PAGE 2 OF APPENDIX C.3 OF THE 2017 ROSES SOLICITATION SINCE IT DEALS WITH THE INTERIOR PROCESSES RESPONSIBLE FOR PRODUCING THE ANCIENT LUNAR MAGNETIC FIELD.