Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 1 MSL LANDING SITE CANDIDATE IN SOUTHWRST HOLDEN CRATER. M. C. Malin and K. S. Edgett Malin Space Science Systems San Diego, CA Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 1

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 2 Why Holden? Well exposed, layered rock Erosional Expression includes many shallow slopes without stair-stepping One of the best (among a very rare form of occurrence) of both light and dark layers (beware MER/Endurance lesson) Erosional expression (undermining and collapse of several layers acting as cap- rocks) suggests the presence of multiple lithologies Site may be too rugged to land on, but nearby fans (probably alluvial?) provide easier access as a “Go-TO” landing site, with the advantage that the fans themselves may also be of considerable interest

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 3 Areography Holden Crater is about 150 km in diameter The 20 km circle shown is centered at 26.66°S, 35.05°W (areograhic coordinates) Uzboi Vallis, a component of the Surinda, Runa, Uzboi Valles system between Nirgal and Ladon Valles, enters the crater from the SW

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 4 Relief The floor of Holden is about 2 km below the mean MOLA elevation Regional relief ( ~ 1000’s m is < 100’s m The fans slope to the east at about 2-2.5°. The fan lobes are ~ 100 m thick Local transverse relief on the surface of the fans is ~ 10’s m for of 100’s of m Local relief in the areas of layered rock outcrop is < 100 m, declivity of gentle layered slopes is a << 10°

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 5 Stratigraphy and Geologic History Holden impact occurred after Eberswalde to the north; target material may have been layered rock (occasional layered outcrops on uplands surrounding Holden and at some distance away) Layered material emplaced within Holden; then lithified Subsequent fluvial history eroded and buried layered rock Fluvial erosion of western wall (ridges of layered rock perpendicular to wall, subsequently embayed and buried by fans Uzboi Vallis breaches crater rim around this time and entrenches into layered rock at base of southwest wall The layered rock in SW Holden are NOT sediments from Uzboi

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 6 Habitability (?) Pros Closed, sedimentary basin Region with substantial evidence for both surface- and ground-water Sediments and sedimentray rock protected by overburden Cons Ancient Cyclic environmental change Almost 30° from equator (fairly strong seasonal illumination and thermal conditions)

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 7

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 8

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 9

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 10

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals. 11

Mars Global Surveyor Mars Orbiter Camera 8 May 2006 Confidential and Proprietary Material of MSSS. This document may contain information subject to the International Traffic in Arms Regulations (ITAR) or the Export Administration Regulations (EAR). This document may not be further exported, released, or disclosed to foreign nationals or any foreign entity without first obtaining the appropriate export approvals Why Holden? Well exposed, layered rock Erosional Expression includes many shallow slopes without stair- stepping One of the best occurrences of both light and dark layers Erosional expression suggests the presence of multiple lithologies Mexican Hat Rock, Utah