THE OVERALL OBJECTIVE OF THIS PROPOSAL IS TO CONSTRAIN FUNDAMENTAL PROPERTIES OF MARS' CORE EVOLUTION AND PAST DYNAMO ACTIVITY. THE CRUSTAL MAGNETIC FIELD OF MARS WAS GENERATED BY A DYNAMO IN ITS EARLY HISTORY. THE FIELD IS ANOMALOUS IN THAT IT IS MORE INTENSE IN THE SOUTHERN HEMISPHERE THAN THE NORTHERN HEMISPHERE. IN ADDITION THE INTENSITY IN CERTAIN REGIONS IS ABOUT 20 TIMES STRONGER THAN CRUSTAL FIELDS FOUND ON EARTH. EXPLANATIONS HAVE BEEN PROPOSED FOR THIS SPATIAL STRUCTURE INCLUDING A HEMISPHERIC MARTIAN DYNAMO THAT PRODUCES STRONGER FIELD INTENSITIES IN THE SOUTHERN HEMISPHERE OR POST-DYNAMO CRUSTAL DEMAGNETIZATION MECHANISMS. UNDERSTANDING THE ANCIENT MARTIAN DYNAMO IS IMPORTANT BECAUSE IT PLACES CONSTRAINTS ON MARS' THERMAL HISTORY AND BECAUSE THE RESULTING MAGNETIC FIELD MAY HAVE IMPLICATIONS FOR ATMOSPHERIC LOSS MECHANISMS. HERE WE PROPOSE TO USE DATA COLLECTED BY THE INSIGHT MISSION RELEVANT TO THE COMPOSITION STRUCTURE AND THERMAL STATE OF THE INTERIOR TO INFORM PARAMETER CHOICES IN NUMERICAL DYNAMO SIMULATIONS AND THERMAL EVOLUTION MODELS. THESE SIMULATIONS WILL ADDRESS OUTSTANDING QUESTIONS RELATED TO THE ENIGMATIC MARTIAN MAGNETIC FIELD INCLUDING THE POWER SOURCE FOR THE DYNAMO THE TIMING OF ITS ONSET AND DEMISE THE INTENSITY AND MORPHOLOGY OF THE RESULTING SURFACE MAGNETIC FIELD AND ITS REVERSAL PROPERTIES. RESULTS FROM THESE DYNAMO SIMULATIONS WILL ALSO INFORM MARTIAN TRUE POLAR WANDER STUDIES BY DETERMINING WHETHER A TIME-AVERAGED AXIAL DIPOLAR SURFACE FIELD (I.E. THE GAD HYPOTHESIS) IS REASONABLE FOR ANCIENT MARS. THE RESULTS ARE DIRECTLY RELATED TO THE MISSION'S SCIENCE GOAL A) "UNDERSTAND THE FORMATION AND EVOLUTION OF TERRESTRIAL PLANETS THROUGH INVESTIGATION OF THE INTERIOR STRUCTURE AND PROCESSES OF MARS". ALTHOUGH THE OBJECTIVES UNDER THIS GOAL DO NOT ADDRESS DYNAMO GENERATION DIRECTLY ALL THE GOAL A OBJECTIVES DIRECTLY INFORM DYNAMO STUDIES. ADDING DYNAMO INVESTIGATIONS TO THE MISSION IS THEREFORE A NATURAL EXTENSION AND WILL ENHANCE THE SCIENTIFIC RETURN FROM THE INSIGHT MISSION.