Meet the
Scientist: Dr. Jack Farmer
by Veronica Ann Zabala
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Dr. Jack Farmer
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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?
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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.
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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.
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Stromatolites
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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
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