PLANET FORMATION CONCLUDES WITH COLLISIONS OF PROTOPLANETS THAT LEAD TO A MYRIAD OF PRESENT-DAY FEATURES IN OUR SOLAR SYSTEM INCLUDING THE LARGE CORE OF MERCURY THE EARTH S MOON AND THE PLUTO-CHARON SYSTEM. GIANT IMPACTS GENERATE A SIGNIFICANT AMOUNT OF BOUND AND ESCAPING DEBRIS; HOWEVER CURRENT PARAMETERIZED HYDRODYNAMIC STUDIES ONLY DESCRIBE THE LARGEST ONE OR TWO REMNANTS IN MINIMAL DETAIL. THESE STUDIES ALSO LACK KEY ANGLE SIZE-SCALE AND COMPOSITION DEPENDENCE OF GIANT IMPACT OUTCOMES NECESSARY FOR INFORMING CUTTING-EDGE N-BODY PLANETARY EVOLUTION MODELS. DUE TO THESE DEFICIENCIES CURRENT N-BODY CODES LACK THE ABILITY TO ACCOUNT FOR THE ORBITAL DAMPING OF TERRESTRIAL PLANETS AND THE MIXING OF MATERIAL BETWEEN PLANETARY BODIES. THE NATURE OF GIANT IMPACT DEBRIS IS PARAMOUNT IN UNDERSTANDING THE GENESIS OF SMALL BODY POPULATIONS SATELLITE SYSTEMS AND RE-IMPACTING BOLIDES. FOR EXAMPLE EVIDENCE OF DEBRIS FROM THE MOON-FORMING GIANT IMPACT WAS FOUND IN THE MAIN-BELT ASTEROID POPULATION. COLLISIONS WILL NOT ONLY PREFERENTIALLY EXCAVATE ICY OR ROCKY MANTLE MATERIAL BUT ESCAPING DEBRIS ON HELIOCENTRIC ORBITS WILL SERVE AS A HEAT SOURCE IN THE FORM OF RE-IMPACTING BOLIDES FOR TENS IF NOT HUNDREDS OF MILLIONS OF YEARS. IT HAS ALSO BEEN SHOWN THAT NEARLY EQUAL AMOUNTS OF DEBRIS FROM THE MOON-FORMING IMPACT CAN BE DISTRIBUTED ONTO VENUS AS ONTO EARTH. THIS SUGGESTS GIANT IMPACT DEBRIS PLAYS AN INTIMATE ROLE IN THE DEVELOPMENT OF PLANETARY SURFACES AND THAT VOLATILE MANTLE MATERIAL CAN BE EFFECTIVELY TRANSPORTED THROUGHOUT THE SOLAR SYSTEM. I WILL DEVELOP A COMPREHENSIVE DESCRIPTION OF THE AFTERMATH OF GIANT IMPACTS WHERE THE DYNAMICAL PARAMETERS AND COMPOSITIONAL DIVERSITY OF BOTH THE LARGEST REMNANTS AND THE DEBRIS WILL BE OUTLINED. I WILL PAY PARTICULAR ATTENTION TO THE SCALE- AND ANGLE-DEPENDENCE OF EXCAVATED MANTLE MATERIAL INCLUDING THAT OF WATER AND SILICATES AND TO THE TRAJECTORY ON WHICH THIS DEBRIS ESCAPES. THIS WORK WILL LEVERAGE AN EXISTING SUITE MORE THAN 1500 HIGH-RESOLUTION SMOOTHED PARTICLE HYDRODYNAMICS (SPH) GIANT IMPACT SIMULATIONS DEVELOPED OVER SEVERAL YEARS. THIS DATABASE SPANS THE WIDEST RANGE OF PRE-IMPACT CONDITIONS TO DATE AND INCLUDES COMPOSITIONS AND SIZES ANALOGOUS TO BOTH INNER AND OUTER SOLAR SYSTEM OBJECTS. RESULTS WILL BE MADE PUBLICLY AVAILABLE IN AN ONLINE DATABASE TO ENCOURAGE CROSS-VERIFICATION OF GIANT IMPACT OUTCOMES IN OTHER SPH CODES USED IN THE COMMUNITY. PUBLISHED SCALING LAWS WILL BE DESIGNED SUCH THAT THEY ARE READILY ADOPTED INTO EXISTING PLANETARY EVOLUTION MODELS E.G. N-BODY PLANET FORMATION CODES.
$67,967FY2020National Aeronautics and Space AdministrationNASA
Arizona State University, Scottsdale AZ