2012 Annual Science Report
Arizona State University Reporting | SEP 2011 – AUG 2012
Habitability of Water-Rich Environments, Task 4: Evaluate the Habitability of Ancient Aqueous Solutions on Mars
As a member of the MSL Science team, Prof. Farmer actively supported surface operations of the Mars Science Laboratory rover Curiosity at JPL throughout the first 90 days of the mission (ongoing). During this time he offered a videocon-based upper division/graduate level course from JPL each week. (GLG 455/598: Advanced Field Geology – The MSL Mission Live from Mars). Prof. Farmer also completed a Raman-based study of sulfate evaporites to assess the biosignature preservation potential of this important Mars analog rock type. The work was done in collaboration with J.W. Schopf at UCLA and was published last Spring in the journal, Astrobiology. With Dr. Steve Ruff (Research Assoc., ASU), Prof. Farmer continued terrestrial analog studies in Yellowstone National Park and at Mauna Loa, Hawaii, to understand sulfate- and silica-precipitating hydrothermal systems documented at Home Plate in the Columbia Hills of Gusev Crater, Mars in 2011.
Prof. Zolotov developed models to predict the clay mineralogy of Mawrth Vallis, a potential future landing site for Mars astrobiology. His work suggested that this region of Mars has experienced extensive acidic weathering under a low rock:water ratio. His work also provided insights into the nature of potentially habitable subsurface environments at Mawrth Vallis.
Both projects have achieved milestones in the exploration for habitable environments. Zolotov and collaborators modeled expected clay mineral assemblages at Mawrth Vallis, Mars. The model results did not match the empirical observations, but model predictions were partially reproduced by spectral observations from orbit, when large volumes of water were used. This result was consistent with strong acidic weathering of the Martian surface. Their models also provided new insights into the nature of subsurface habitable environments on Mars.
Farmer and his MSL team collaborators began surface operations at Gale Crater on August 6. The spacecraft landed at a site where geomorphology suggests that fluvial (river) processes were active in the past. The discovery of pebbly conglomerates, having well-rounded, well-sorted clasts at Bradbury Station landing site is consistent with this hypothesis. MSL continues to explore these possible alluvial fan deposits on the way to layered stratigraphic sequences at a site to the west called Glenelg, Eventually we will continue the search for ancient water at the base of Mt. Sharp. Along its traverse, Curiosity continues to deliver unprecedented results from its payload of instruments, which promises to re-write the textbooks.