Paper No. 3
Presentation Time: 2:10 PM
DESTINATION SOUTH POLE-AITKEN BASIN: SAMPLE RETURN, GEOLOGY OF THE MOON, AND RECORD OF SOLAR SYSTEM CATACLYSM
JOLLIFF, B.L., Earth and Planetary Sciences, Washington University, One Brookings Drive, Campus Box 1169, St. Louis, MO 63130, GADDIS, L.R., Astrogeology Team, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, SHEARER, Charles K., Institute of Meteoritics, Univ of New Mexico, Albuquerque, NM 87131, COHEN, Barbara, NASA Marshall Space Flight Center, 320 Sparkman Dr, Huntsville, AL 35812, HAGERTY, Justin J., United States Geological Survey, Astrogeology Science Center, 2255 N. Gemini Drive, Flagstaff, AZ 86001, HEAD, James W., Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI 02912, PETRO, Noah, Geodynamics Branch, NASA/GSFC, NASA/GSFC, Building 33, Code 698, Greenbelt, MD 20771, PIETERS, Carle M., Geological Sciences, Brown University, Box 1846, Providence, RI 02912, WARREN, Paul H., Institute of Geophysics, UCLA, Los Angeles, CA 90095 and ZEIGLER, Ryan A., Earth and Planetary Sciences, Washington University, Campus Box 1169, One Brookings Drive, St. Louis, MO 63130, blj@wustl.edu
The Moon’s South Pole-Aitken basin (SPA) is identified in NRC reports as a high priority for Solar System Exploration. As the largest and oldest clearly recognizable impact basin on the Moon, it holds a record of the early cataclysmic bombardment of the Moon and the inner Solar System at a critical time in the evolution of early habitable environments on Earth. The geochemical anomaly that is still associated with the SPA basin reflects components of the lower crust and possibly the upper mantle of the Moon. As such, its materials brought to the surface or incorporated into impact melt rocks hold keys to understanding the lower crust and crust-mantle transition, as well as the thermal evolution of the Moon. Volcanic glasses and basalts from this region of the Moon, far distant from the limited, sampled regions of the near side, will permit a better understanding of mantle heterogeneity that may be associated with global crustal compositional asymmetry.
New data provided by recent missions, including Kaguya, Chandrayaan, and LRO, reveal details of the topography, geomorphology, mineralogy, impact deposits, and volcanics that facilitate scientific site selection for sample return. We will describe the objectives and scientific rationale for site selection for the MoonRise mission concept to land in the interior of SPA basin, collect rock samples, and return them to Earth for analysis in terrestrial laboratories. Such samples will include crystalline impact materials that can be used to determine the age of SPA basin formation and of impacts that have occurred subsequently within the basin, thus providing key constraints on the bombardment chronology. These samples will provide ground truth for orbital data and context for interpretation of rock types and mineralogy across the basin, and thus a better understanding of giant impact-basin formation processes and effects. Potential landing sites will be discussed, highlighting new data obtained by recent missions.
