BACKGROUND: PLANETARY REGOLITH IS THE MEDIUM BY WHICH WE INVESTIGATE THE EVOLUTION OF PLANETARY SURFACES. IT IS WHAT WE SENSE WITH REMOTE SENSING AND THE MATERIAL WE RETURN WHEN COLLECTING SAMPLES. THE DOMINANT FORCE SHAPING AND RE-SHAPING THE REGOLITH ON AIRLESS BODIES IN THE SOLAR SYSTEM IS IMPACT BOMBARDMENT. WE HAVE RECONSTITUTED THE PIONEERING LUNAR REGOLITH OVERTURN MODEL PRESENTED BY GAULT ET AL. (1974). KEY UPDATES ARE THE INCLUSION OF VARIABLE MATERIAL PROPERTIES AND SECONDARY IMPACTS. THESE UPDATES CONTRIBUTE AN IMPROVED UNDERSTANDING OF THE IMPACT PROCESSING OF THE LUNAR SURFACE AND BROADEN THE APPLICABILITY OF THE MODEL BEYOND ITS ORIGINAL INTENT. A PAPER PRESENTING THE UPDATED MODEL AND LUNAR APPLICATION INCLUDING SECONDARIES AND VALIDATION IS CURRENTLY IN REVIEW WITH ICARUS. THE PROJECT WILL PRODUCE NEW INSIGHTS FOR FOUR OBJECTS THROUGH APPLICATION OF THIS REJUVENATED REGOLITH EVOLUTION MODEL. THE THICKNESS OF THE LUNAR HIGHLANDS REGOLITH WILL BE MODELED TO PROVIDE AN ESTIMATE OF THE PRE-ORIENTALE IMPACT FLUX THAT WOULD BE REQUIRED TO GENERATE THE MEASURED REGOLITH. EXISTING ESTIMATES ARE BASED ON CRATER COUNTS; THE PROJECT WOULD SUPPLY INDEPENDENT INSIGHT. THIS NEW ESTIMATE IS RELEVANT BOTH TO THE INTENSITY OF THE FINAL BOMBARDMENT OF THE MOON AND INNER PLANETS AND TO THE AGE AT WHICH THE LUNAR CRUST SOLIDIFIED SUFFICIENTLY TO PRODUCE AN UNCONSOLIDATED FRAGMENTAL REGOLITH. THE PROJECT WILL ALSO UPDATE AND POSSIBLY ENTIRELY CHANGE A FUNDAMENTAL PARAMETER IN LUNAR GEOLOGY: THE THICKNESS OF THE HIGHLANDS REGOLITH. THE STARK DIFFERENCE BETWEEN THE ABUNDANCE OF ICE AT THE POLES OF MERCURY AND THE MOON HAS NO CURRENT EXPLANATION OTHER THAN MERCURY HAVING EXPERIENCED A RECENT SERENDIPITOUS LARGE ICY IMPACT. HOWEVER THE IMPACT FLUX AT MERCURY AT REGOLITH-PRODUCING SIZES IS SUBSTANTIALLY LOWER THAN AT THE MOON. OUR ANALYSIS WILL DETERMINE IF REGOLITH OVERTURN CAN EXPLAIN THIS UNRESOLVED PROBLEM IN SOLAR SYSTEM VOLATILES. CERES TOO POSSESSES ICE DEPOSITS IN PERMANENT SHADOW AND ITS LATITUDE DEPENDENT SHALLOW BURIED ICE DISTRIBUTION APPEARS TO BE CONSISTENT WITH THERMAL MODELS. HOWEVER THE MODEL DEPTH TO ICE NEAR THE POLES IS EXTREMELY SHALLOW AND THUS APPEARS TO BE READILY SUSCEPTIBLE TO DOMINANCE BY REGOLITH OVERTURN. THIS PROJECT WILL CLARIFY THE IMPORTANCE OF REGOLITH OVERTURN IN UNDERSTANDING SHALLOW ICE ON CERES. FINALLY EUROPA IS A LIKELY TARGET FOR SURFACE SAMPLING BY A LANDER TO SEEK EVIDENCE OF LIFE THROUGH CHARACTERIZATION OF ORGANIC MOLECULES. HOWEVER RADIATION RAPIDLY BREAKS DOWN ORGANIC MOLECULES MAKING SOME FORM OF SUBSURFACE SAMPLING DESIRABLE. THIS PROJECT WILL DETERMINE THE DEPTH TO MATERIAL THAT HAS NOT BEEN CYCLED TO THE RADIOLYTICALLY ALTERED SURFACE DIRECTLY RELEVANT TO UNDERSTANDING THE NATURE OF ANY EUROPA SAMPLE.