2011.5.12 D1 1
(2010 Sep.-2011 April) Titan s global crater population: A new assessment Neish & Lorenz, PSS in-press Distant secondary craters from Lyot crater, Mars, and implications for surface ages of planetary bodies Robbins & Hynek (2011) GRL Global distributions of large lunar craters: implications for resurfacing and impactor populations Head et al. (2010) Science Eminescu impact structure: Insight into the transition from complex crater to peak-ring basin on Mercury Shon et al., PSS in-press 2 2
Titan s global crater population: A new assessment Neish & Lorenz, PSS Cassini, (Lorenz et al., 2007) Cassini RADAR coverage Coverage(33 %) Titan Impact flux, 1 Ga, 200 Myr Crater size-frequency distributions of several planets 3 3
Titan s global crater population: A new assessment Neish & Lorenz, PSS Crater Impact rate Korycansky & Zahnle (2005) Arteieva & Lunine (2005), 1 Ga, 200 Ma Titan (Tobie et al., 2006) Crater size-frequency distribution and predicted crater distributions from two different impact rate models 4 4
Distant secondary craters from Lyot crater, Mars, and implications for surface ages of planetary bodies Robbins & Hynek, GRL Lyot crater crater, Lyot crater and its near-field secondaries crater (~5000 km), Lyot, 143 Cluster (5341 craters) Crater Crater Secondary crater clusters from Lyot 5 5
Distant secondary craters from Lyot crater, Mars, and implications for surface ages of planetary bodies Robbins & Hynek, GRL, 1719 cluster; 700 km( ~6R)-5200 km (46 R) cluster Lyot 143 clusters, 5341 (10-300 craters each; D>800m) Size-frequency distribution of secondary craters (SFD) (-5~-6), km,, 6 6
Global distributions of large lunar craters: implications for resurfacing and impactor populations Head et al., Science LRO crater, Resurfacing Impactor Global distribution of craters LRO (D 20km, 5185, 2 ) Slope map using LRO DTM 7 Orientale, Imbrium, Nectaris, Crater counting Impactor Orientale (3.8 Ga) Orientalecrater 7
Global distributions of large lunar craters: implications for resurfacing and impactor populations Head et al., Science Orientale Orientale basin and radial distribution of craters Impactor, Mare Orientale (3.8 Ga) Impactor Population Near Earth Asteroids Main Belt Asteroids Storm et al. (2005) Crater size frequency distribution 8 8
Eminescu impact structure: Insight into the transition from complex crater to peak-ring basin on Mercury Schon et al., PSS Peak-ring basin, Eminescu MESSENGER Eminescu crater and its peak ring Transition of crater morphology Complex crater Multi-ring basin (<1 Ga) MESSENGER Head (2010) Peak-ringmelt cavity Floorimpact melt 9 9
Eminescu impact structure: Insight into the transition from complex crater to peak-ring basin on Mercury Schon et al., PSS Crater sizefrequency distribution (SFD) of Eminescu (<1Ga) Crater floor deposit ejecta 10 Possible mechanism of peak ring basin formation (Head, 2010), Impact melt Peak-ring basin Head (2010) nested melt cavity model Melt cavity Peak shock stress zone Peak ring. Central peak. Melt cavitymelt, floor 10
Bibliography Titan s global crater population: A new assessment Neish, C. D. and Lorenz, R. D. Planet. Space Sci. in-press Distant secondary craters from Lyot crater, Mars, and implications for surface ages of planetary bodies Robbins, S.J., and Hynek, B. M. GRL 38, L5201 Global distributions of large lunar craters: implications for resurfacing and impactor populations Head, J. W. et al. (2010) Science 329, 1504-1507 Eminescu impact structure: Insight into the transition from complex crater to peak-ring basin on Mercury Schon S. C. et al., Planet. Space Sci. in-press 11 11