Scientist: Dr. Jack Farmer|
by Veronica Ann Zabala
Q: What are your areas of research?
A: Microbial biosedimentology and paleontology, early biosphere evolution, astrobiology.
Q: How did you choose your current research?
A: I specialized in paleobiology and sedimentology in graduate school. I began to work with microbial ecosystems and to apply this knowledge to problems of early biosphere development during the early 80’s when I was at UCLA. I moved into applications to Mars exploration in the early-90’s, after beginning work as a research scientist at NASA Ames Research Center.
Q: How is your research related to studying Mars?
A: I have been interested in how to apply our knowledge of early biosphere evolution based on the fossil record of Earth to strategic planning for Mars exploration. We now have a record of life on Earth that goes back to the oldest rocks available for study. However, although life seems to exist about anywhere liquid water is available, preservation of fossil biosignatures is quite narrowly limited to only certain types of aqueous environments and their deposits. My research has been aimed at understanding the factors that control biosignature preservation and how that knowledge can be translated into an exploration strategy for Mars. When I began this research in the mid-90’s, only a few of us had actively thought about such things, and essentially no one had considered the implications for strategic planning. Out of that work came a new subdiscipline of astrobiology which I call exopaleontology. The past half dozen years have been quite productive for Mars exopaleontology with the application of basic principles to developing exploration strategies for Mars. Interest in the field was consolidated with the report of putative biosignatures in martian meteorite, ALH 84001 (still controversial!). With that development, the Mars Program also became more responsive. In practical terms, the exploration for past life is now a primary driver in the robotic program. I have had numerous opportunities the past 6 years to provide input into Mars mission planning through my involvement with numerous NASA mission planning activities.
Q: You are currently looking for future Mars landing sites: how is a landing site selected and what are the mission priorities?
A: The selection of landing sites is a crucial step for implementing the strategy for Mars astrobiology. If we land in the wrong place, we will not be able to access the most favorable past or present environments for life. The search involves the detection of sites where two things coincided: 1) conditions for persistence of life and 2) conditions for the capture and preservation of biosignatures. We know that the most fundamental requirement for life is liquid water, so the search for sites is first and foremost driven by the search for past or present water. But within aqueous environments, we also know that special conditions are required for the preservation of biosignatures. The two most important geological environments for biosignature preservation are 1) sites of rapid mineral precipitation (e.g. mineralizing springs, evaporative lakes, etc.) and 2) low energy, anoxic lake environments where fine-grained, clay-rich sediments (e.g. shales, water-lain volcanic ash, etc.) were deposited. Virtually all fossil microbial biosignatures found in the Precambrian record on Earth are found in these settings. In concert with the above requirements, the goal in our site selection research has been to locate and characterize the places on Mars where liquid water was present on the surface for prolonged periods and where geological environments were also favorable for the capture and prolonged preservation of fossil biosignatures. We approach the first step (question of liquid water) primarily through the identification and study of geomorphic features that represent surface modification (erosion or deposition) by flowing or standing bodies of water. This involves careful analysis and interpretation of Viking and, more recently, Mars Observer Camera (MOC) orbital imaging of the martian surface. The question of favorable geological conditions (environments) for biosignature preservation is more involved and requires the detection of certain classes of aqueously-formed minerals that are precise paleoenvironmental indicators. The Thermal Emission Spectrometer (TES) which is presently in orbit around Mars is providing a first global look at that type of information. Initial results suggest that certain sites where the geomorphology indicates that water was once present, were also sites of active aqueous mineral precipitation (specifically, specular hematite). But higher resolution mapping will be needed to really identify and map the distribution of other, potentially more important minerals like carbonates and sulfates. This will be possible with the T H E M I S instrument on the Mars Odyssey orbiter.
Q: What missions have you been involved with?
A: I was involved with landing site selection for Mars Pathfinder and the 2003 mission (I am a member of the NASA’s 2003 Landing Site Steering Committee). I was also a member of the science definition teams for the Mars 2001 and 2005 missions. Over the past year, I also participated in the recent re-vamping of the Mars Program architecture as Chair of the Life Subgroup for NASA’s Mars Exploration Program (now Payload) Advisory Group. Finally, I am a member of the Space Sciences Advisory Committee which advises NASA on how to develop and implement the agency’s strategic plan to explore the Solar System.
Q: How do the NASA cutbacks affect your research? What solutions do you have for the future of Mars Exploration?
A: Clearly, research requires funding. With cut-backs, the process always suffers. Perhaps the most limiting thing I have faced is overly cost constrained missions which require cut-backs in science payload and mission scope. This has been a persistent problem in the Mars Program since I have been involved, and has occurred for a variety of reasons. I think everyone shares the goal to establish a stable funding environment where full implementation of what are now very well-established science goals, will be assured. Otherwise the ongoing investment in research and strategic planning becomes an exercise in futility where we are called upon to “re-invent the wheel” every few years. I would say that the long-term solutions lie in Congress and the agency being willing to make a long-term commitment to implement the well-defined Program and science strategy by stabilizing the funding environment so that the missions are protected against erosion. I also think we need to continue to protect Research and Data Analysis Programs against cut-backs, and in fact find productive ways to expand those programs to expand the opportunities for more scientists, particularly those just being trained, to become involved in missions.
Q: Where can we get more information about what you do?
A: I would recommend ASU’s Astrobiology Program website (http://astrobiology.asu.edu/) which has a lot of links to other interesting sites.
Q: If you were among the first to go to Mars, what three items would you bring along with you?
A: A rock hammer, hand lens and a four-wheel drive mini-van!
Veronica Ann Zabala is an undergraduate student currently attending Arizona State University majoring in Geology. Veronica is the President of the Arizona State University and Phoenix Chapters of the Mars Society. She is currently analyzing the aeolian dynamics of Mars from interpretation of data from Mariner 9, Viking Orbiter and Mars Global Surveyor (MOC) images. Along with atmospheric circulation models, the determination of the aeolian history on Mars can be investigated to determine surface-atmosphere interactions and aid in the selection of future landing sites on Mars. GeoBum@prodigy.net