1. Preservation of Evidence of Ancient Environments and Life on Mars
Mars today
Early Mars ?
The pace of discovery in space is quickening, spurred on by new technologies.
The costs and capabilities of robotic space exploration have changed dramatically since the dawn of the space age.
Robotic spacecraft allow us to explore the age old questions about the universe…..
How did life begin? Does life exist elsewhere? Do habitable conditions exist elsewhere?
David J. Des Marais
NASA Ames Research Center

2. Preservation: topics Noachian-Hesperian environments & processes
Persistence of ancient aqueous environments
Nature of deposits in Noachian aqueous environments
Phyllosilicate deposits & organic matter concentrations
Preservation potential of the four “finalist” MSL sites

4. Importance of Age

5. Meridiani Planum and the Global Hydrology of Mars
Importance of Elevation B A B A
detected evaporite deposits
Andrews-Hanna et al. (2007)

6. Stream Systems
Stepinski & Luo, LPSC41, 2010

7. Gusev Crater ~180 km diameter Apollinaris Patera (volcano) Northern
Lowlands
Southern
Highlands x
Ma’Adim
Vallis
Gusev Crater
~180 km diameter

8. Orbiter view (MRO HiRISE) Husband Hill and Inner Basin ground view (MER Pancam)

9. Importance of Age and Depth in Crust

10. Oyama Crater & Mawrth Vallis
bedrock exposures have a light tone;
some dark-toned materials in this area are also bedrock (commonly but not always a caprock above light-toned rocks)
“Mawrth mouth”
Mawrth Vallis
regolith covers bedrock in the ‘intermediate gray’ areas – some of that regolith is considered to be eolian-deposited dust and/or crusted eolian dust (e.g., Presley and Arvidson 1987)
candidate MSL field site
note Oyama formed in light-toned bedrock
Oyama
(107 km diam)
Mawrth Vallis
MGS MOC red wide angle mosaic
Mawrth Vallis
The name “Oyama” was approved by the IAU 26 March 2010.
Named for Vance I. Oyama, Viking Gas Exchange Experiment PI.
MSL Science Team Field Site Discussions – Mawrth
Note: Candidate landing ellipse size and shape is approximate. 10

11. Pilbara Craton and Hamersley Range, W. Australia

13. Mars Global Surveyor MOLA Topography

14. Marine Chlorophyll Abundances (Low Moderate High)

16. Key Factors:
Paleo-productivity
Sedimentary redox
Mineralogy
Lithification
Later alteration

17. Pilbara Craton and Hamersley Range, W. Australia

18. Preservation of Evidence about Ancient Mars
Noachian-Hesperian environments and processes
Persistence of ancient aqueous environments
Noachian deposits in aqueous environments
Phyllosilicate-rich deposits and organic matter contents
Preservation potential of the four “finalist” MSL sites
Age of deposits: mid-Noachian to early Hesperian
Water persistence: effects of elevation and geologic age
Allochthonous vs autochthonous phyllosilicates
Redox state of deposit
Lithification: rate and extent