2008 Annual Science Report
University of California, Berkeley Reporting | JUL 2007 – JUN 2008
The UC Berkeley-led BioMARS team continues its efforts to integrate information about the coupled hydrologic, geomorphic, and tectonic evolution of Mars and its mineralogical and geochemical composition with geomicrobiological data from Earth analog ecosystems to support the scientific framework for the search for evidence of past or current life on Mars. The project combines a strong field-based research effort coupled with modeling and/or laboratory work utilizing state-of-the-art technologies. This combination of approaches aims to constrain geological habitats on Mars, either past or present, with what we can learn about potential metabolisms for life there based on these Earth-analogs. The ultimate goal of this work is to suggest where and what we might look for to discover life, or its vestigial traces, on Mars.
We have carried out geomorphological studies aimed at investigating processes that potentially have shaped the Martian surface. We discovered that Box ... Continue reading.
On Mars and Earth, deep canyons with steep walls and no tributaries are found to terminate upstream in sharp amphitheater-shaped heads. For decades researchers have interpreted such features as being created by springs draining deep groundwater which undermine the head and advance it forward, with important implications for the history of climate on Mars. We have found through extensive field study of these features on Earth that such canyons are formed by waterfall erosion rather than by groundwater seepage. Hence, this morphology on Mars does not reliably indicate sustained groundwater discharge. This requires reconsideration of the interpretation of these features and of their significance as indicators of Mars environmental history.ROADMAP OBJECTIVES: 1.1
We investigate the possible origin and fate of oceans early in Martian history.ROADMAP OBJECTIVES: 1.1 2.1
We are analyzing spectral data of Mars including i) CRISM images for the presence of phyllosilicates and sulfates and ii) MER Gusev crater Pancam data of the bright salty soils. This also involves characterizing the spectral properties of i) phyllosilicates and sulfates having a variety of mineral structures, and ii) altered volcanic material containing phyllosilicates and sulfates.
Work this year on the bright salty soils found at Paso Robles and other sites in Gusev crater showed that this material is composed of the ferric minerals ferricopiapite, fibroferrite and/or ferristrunzite (Lane et al., 2008, Parente et al., 2008). Pancam multispectral visible/near-infrared (VNIR) images of Mars from Gusev crater are shown in Figures 2 and 3. Analysis of these Pancam data together with the mini-TES and Mössbauer data collected by MER enabled characterization of the minerals in the bright salty soils.
Our work analyzing the clay minerals at Mawrth Vallis, Mars, has shown the presence of a large clay deposit that suggests long-standing water on Mars (Bishop et al., 2008). The stratigraphy of the phyllosilicates indicates a complex and interesting aqueous chemistry.
During this year we also completed a study on alteration near Kilauea, Hawaii, where solfataric alteration of ash deposits is taking place and where orange-colored Fe-Ti-S-Si-bearing coatings are forming near vent sites on lava. We are in the process of preparing a manuscript for publication on this study.ROADMAP OBJECTIVES: 2.1
The interior evolution of Mars influences the evolution of its atmosphere through volcanic outgassing. The atmosphere in turns influences the stability of liquid water on or near the surface and the radiation environment on the surface — two key aspects of planetary habitability,ROADMAP OBJECTIVES: 1.1 2.1
Atmospheric chemistry has profound implications for the climate and habitability of Mars throughout its history. The presence and stability of greenhouse gases and aerosols, for example, may regulate climate or force climate change. Chemical reactions in the atmosphere initiated by light (“photochemistry”) may also produce gases or aerosols that serve as a shield against ultraviolet light (as stratospheric ozone does on earth) and possibly warm or cool the surface, which, in turn, has implications for the presence and stability of water on Mars. Thus, understanding the chemical composition and physical properties of possible Martian atmospheres over time is vital to the understanding of the opportunities and challenges for early life on Mars, as well as the importance of habitat features that provide radiation protection. In this project, we are investigating in laboratory experiments how quickly photochemistry can destroy and produce various greenhouse gases and aerosols and whether or not the aerosols may serve to warm or cool the surface. We are also investigating whether or not these photochemical reactions can produce carbon-rich aerosols that might be depleted in the stable isotope carbon-13 relative to carbon-12, and thus might be mistaken for an isotopic signature produced by biological processes after the aerosols settle out of the atmosphere and become incorporated into the martian rock record or meteorites that have made it to earth.ROADMAP OBJECTIVES: 1.1 1.2 3.1 6.1 7.1 7.2
This project explores robotic aids to astrobiology in the form of remotely controlled mobile agents with the ability to do human-like tasks in earth and mars like environments. Ethnographic studies are conducted to determine the microgeobiologist and geochemists abilities to use robotic interfaces to collect data and samples in liquid based and liquid-solid interface locations such as seeps, shallow water, surf-zone etc. Several robots are designed and constructed: Robots capable of achieving astrobiologist tasks (in situ testing, sample acquisition) Robots with high mobility to reach harsh environments (amphibious, acidic, saline) Astrobiologist-capable interfaces (long distance teleoperation, multi-modal)ROADMAP OBJECTIVES: 2.1 2.2 5.1 5.3
This project focuses on the geochemical and microbiological properties of iron (Fe) and sulfur (S) based lithotrophic microbial ecosystems. Recent aspects of this research have been supported by a Director’s Discretionary Fund (DDF) project entitled “Biogeochemical forensics of Fe-based microbial systems: defining mission targets and tactics for life detection on Mars”. The Banfield group is examining Fe concretions at the hypersaline Lake Tyrell in Victoria, Australia as analogs for those which formed at Meridiani Planum on Mars, as well as novel uncultivated, ultra-small Archaea in pyrite oxidation-based microbial communities at Iron Mountain, CA. The latter organisms have only a very small number of ribosomes per cell (ca. 92, compared to ca. 10,000 for E. coli in culture), which are positioned around the inside of the inner membrane. The size and highly organized internal structure of these organisms provide clues to the strategies of life at its lower size limits. The Emerson group is investigating natural populations and pure cultures of Fe(II)-oxidizing bacteria in an attempt to better understand how their physiology and ecology influences the mineralogy and geochemistry that are hallmarks of these organisms in the environment. A major focus of this work, in collaboration with the Luther group, has been to gain a better understanding the contribution that neutrophilic, oxygen-dependent Fe(II)-oxidizing bacteria make to Fe(II) oxidation kinetics both in situ and in the laboratory. Additional work has focused on the ultrastructure and behavior of a unique Fe-oxidizing bacterium, Mariprofundus ferrooxydans, isolated from a deep-sea hydrothermal vent that had extensive mats of Fe(II)-oxidizing bacteria. The Luther group has been examining a variety of environments where microbially-driven Fe(II) oxidation occurs, including areas where free sulfide is not present (creeks in VA and Chocolate Pots, Yellowstone National Park) and locations where free sulfide is present [local Delaware Inland Bays and the hydrothermal vents at Kilo-Moana (20°3’S, 176°8’W), located on the East Lau Spreading Centre (ELSC), in the Lau Basin, SW Pacific Ocean]. These studies demonstrate that it is possible to distinguish between abiotic and biotic mechanisms for Fe(II) oxidation using real time measurements. Roden’s group has examined microbial communities and biosignatures in several different Fe-dominated natural systems, including circumneutral pH groundwater Fe seeps in Tuscaloosa, AL; a Pliocene-age weathered volcanic tuff unit in Box Canyon, ID; hypersaline Lake Tyrell; and chemically-precipitated sediments in the Spring Creek Arm of the Keswick Reservoir downstream of the Iron Mountain acid mine drainage site in northern CA. We have also evaluated the composition and function of an anaerobic, nitrate-dependent Fe(II)-oxidizing enrichment culture which is capable of chemolithoautotrophic growth coupled to oxidation of the insoluble ferrous iron-bearing phyllosilicate mineral biotite.ROADMAP OBJECTIVES: 4.1 6.1 7.1 7.2
The isotopic composition of calcium is being investigated as a possible indicator the presence of past life on Mars. The research seeks to separate biological from non-biological effects, estimate the magnitude of the effects, and investigate terrestrial environments that may be analogues of early Martian surface environments. Unexpected results have led to evidence concerning the earliest stages of the formation of Mars.ROADMAP OBJECTIVES: 1.1 2.1 7.1
Carnegie Institution of Washington
Indiana University, Bloomington
Marine Biological Laboratory
Massachusetts Institute of Technology
Montana State University
NASA Ames Research Center
NASA Goddard Space Flight Center
Pennsylvania State University
University of Arizona
University of California, Berkeley
University of Colorado, Boulder
University of Hawaii, Manoa
University of Wisconsin
VPL at University of Washington