1. LPI-JSC Center for Lunar Science and Exploration 2011 Hydrocode Simulation of the Ries Crater Impact This work was conducted as part of a NASA Astrobiology project (David A. Kring, PI). The modeling team included Elisabetta Pierazzo Joseph N. Spitale David A. Kring

2. LPI-JSC Center for Lunar Science and Exploration 2011 Kring (2005) Ries Crater Complex Crater 24-26 km final crater diameter 12-16 km transient crater diameter The impact occurred 14 to 15 Ma The larger crater of a binary impact with a WSW to ENE trajectory; the other crater is called Steinheim

3. LPI-JSC Center for Lunar Science and Exploration 2011 Ries Target Sequence Ries Crater The target sequence is composed of 600 m of sedimentary lithologies and an underlying granitic basement A computer hydrocode called CTH was used to model the impact event. The Malmian limestone thickens from the north to the south. For the model, and average thickness of 150 m was utilized. Pierazzo, Spitale, & Kring (2001)

4. LPI-JSC Center for Lunar Science and Exploration 2011 Hydrocode Simulation of Ries Impact Pierazzo, Spitale, & Kring (2001) Movie of Impact

5. LPI-JSC Center for Lunar Science and Exploration 2011 Ries Target Sequence Pierazzo, Spitale, & Kring (2001) Ries Crater Four time-steps in the hydrocode simulation of the impact event The projectile is 1.6 km in diameter and strikes at an angle of 45º at a velocity of 15 km/s. The trajectory is from WSW to ENE (left to right), so a plume of ejecta is thrown down- range (to the right).

6. LPI-JSC Center for Lunar Science and Exploration 2011 Ries Target Sequence Ries Crater Schematic view of the Ries and Steinheim craters after the impact event Because a sea cross-cut the ejecta ENE of the crater, a lot of that material was eroded. The best preserved impact ejecta deposits occur to the south of the crater

7. LPI-JSC Center for Lunar Science and Exploration 2011 Reconstruction of Ries Transient Crater Transient crater Melt (dark gray zone) extended to a depth slightly greater than 2 km and was dominated by silicate basement lithologies The excavation depth (medium gray zone) approached 2 km The transient crater depth of disturbed rock (light gray zone) approached 5 km Fracturing of the crust extended to depths of about 6 km Kring (2005)

8. LPI-JSC Center for Lunar Science and Exploration 2011 References D.A. Kring (2005) Hypervelocity collisions into continental crust composed of sediments and an underlying crystalline basement: comparing the Ries (~24 km) and Chicxulub (~180 km) impact craters. Chemie der Erde 65, 1-46, invited review. E. Pierazzo, J.N. Spitale, and D.A. Kring (2001) Hydrocode modeling of the Ries impact event. Lunar and Planetary Science XXXII, Abstract #2106.