HYPERVELOCITY COLLISIONS WITHIN THE SOLAR SYSTEM REPRESENT A PRIMARY PROCESS IN THE ACCRETION AND MODIFICATION OF PLANETARY BODIES. IN ORDER TO UNDERSTAND WHAT METEORITES CAN TELL US ABOUT THE EARLY SOLAR SYSTEM WE MUST UNDERSTAND ALTERATION PROCESSES SUCH AS SHOCK METAMORPHISM. A RECORD OF IMPACT PROCESSES ON METEORITE PARENT BODIES IS CONTAINED IN THE SHOCK METAMORPHIC EFFECTS FOUND IN METEORITES. WE HAVE BEEN USING SHOCK EFFECTS IN L CHONDRITES TO ESTIMATE THE PRESSURE AND DURATION OF SHOCK EVENTS TO UNDERSTAND THE IMPACT THAT DISRUPTED THE L-CHONDRITE PARENT BODY 470 MILLION YEARS AGO. SEVERAL IMPORTANT QUESTIONS REMAIN: 1) WHAT HAPPENED TO CHONDRITIC MATERIAL THAT EXPERIENCED EXTREME PRESSURES (>S6) AND WHAT ARE THE SHOCK EFFECTS IN METEORITES BETWEEN S6 AND IMPACT MELTS? 2) HOW DO WE RECOGNIZE THESE HIGHLY SHOCKED SAMPLES IF THE COMMON SHOCK EFFECTS HAVE BEEN ANNEALED OUT? 2) ARE SHOCK EFFECTS AND IMPACT HISTORIES OF OTHER PARENT BODIES SIMILAR TO THOSE OF L CHONDRITES? 3) WHAT WERE THE IMPACT PROCESSES THAT CAUSE SHOCK METAMORPHISM IN OTHER PARENT BODIES? WE WILL ADDRESS THESE QUESTIONS BY APPLYING OUR EXPERTISE FROM STUDYING SHOCKED (S4- S6) L CHONDRITES TO A CAREFULLY SELECTED SET OF L LL H CK CHONDRITES AND MARTIAN METEORITES. ALL SAMPLES WILL HAVE SHOCK VEINS OR DOCUMENTED SHOCK EFFECTS. WE WILL STUDY SAMPLES THAT HAVE BEEN 39AR-40AR DATED IF POSSIBLE SO THAT WE CAN CORRELATE OUR SHOCK AND IMPACT RESULTS WITH IMPACT HISTORY AND DYNAMICS IN THE ASTEROID BELT. WE WILL USE A COMBINATION OF OPTICAL MICROSCOPY RAMAN SPECTROSCOPY SCANNING ELECTRON MICROSCOPY AND MICRO X-RAY DIFFRACTION TO CHARACTERIZE SHOCK EFFECTS HIGH-PRESSURE MINERALS AND MICROSTRUCTURES ASSOCIATED WITH SHOCK VEINS. WE WILL USE FOCUSED ION BEAM AND TRANSMISSION ELECTRON TO INVESTIGATE THE NANO-STRUCTURES OF THESE MATERIALS TO CONSTRAIN FORMATION MECHANISMS AND SHOCK CONDITIONS. WE WILL USE SHOCK PHYSICS AND THERMAL MODELING OF SHOCKMELT QUENCH TO ESTIMATE SHOCK DURATION AND P-T HISTORIES. FINALLY WE WILL USE AUTODYNE HYDROCODE CALCULATIONS TO EXPLORE THE RANGE OF IMPACT SCENARIOS THAT ARE CONSISTENT WITH THE SHOCK PRESSURE AND DURATION INFERRED FROM THE SAMPLES. THIS RESEARCH WILL ALLOW US TO APPLY WHAT WE HAVE LEARNED FROM THE HIGHLY SHOCKED (S6) L CHONDRITES TO OTHER METEORITES AND PARENT BODIES SO THAT WE CAN BETTER UNDERSTAND THE IMPACT HISTORY OF THE SOLAR SYSTEM. THIS RESEARCH WILL ALSO PROVIDE A BETTER UNDERSTANDING OF SHOCK EFFECTS IN METEORITES OVER A HIGHER RANGE OF SHOCK PRESSURES.