TY - JOUR AB - We model the formation of lunar complex craters and investigate the effect of preimpact porosity on their gravity signatures. We find that while preimpact target porosities less than ~7% produce negative residual Bouguer anomalies (BAs), porosities greater than ~7% produce positive anomalies whose magnitude is greater for impacted surfaces with higher initial porosity. Negative anomalies result from pore space creation due to fracturing and dilatant bulking, and positive anomalies result from destruction of pore space due to shock wave compression. The central BA of craters larger than ~215 km in diameter, however, are invariably positive because of an underlying central mantle uplift. We conclude that the striking differences between the gravity signatures of craters on the Earth and Moon are the result of the higher average porosity and variable porosity of the lunar crust. AU - Milbury,C AU - Johnson,BC AU - Melosh,HJ AU - Collins,GS AU - Blair,DM AU - Soderblom,JM AU - Nimmo,F AU - Bierson,CJ AU - Phillips,RJ AU - Zuber,MT DO - 10.1002/2015GL066198 EP - 9716 PY - 2015/// SN - 1944-8007 SP - 9711 TI - Preimpact porosity controls the gravity signature of lunar craters T2 - Geophysical Research Letters UR - http://dx.doi.org/10.1002/2015GL066198 UR - http://hdl.handle.net/10044/1/30046 VL - 42 ER -