Geography of Mars Panel

Association of American Geographers
Las Vegas, NV, March 2009
[ Mars globe centered on Syrtis ]

Organizer and chair:

  • Christine M. Rodrigue, Geography, California State University, Long Beach

Presenters and Panelists

  • Christine M. Rodrigue - California State University, Long Beach
  • Mark Bishop - Planetary Science Institute
  • Stephen Tooth - Aberystwyth University
  • Maria Lane - University of New Mexico
  • Jason Dittmer - University College London

Session Abstract.

Geographers have become active contributors in the investigation of Mars and other extraterrestrial bodies, judging from author affiliations in research articles and conference presentations. Most of these are physical geographers or GIScientists, but Mars has also become a topic of human geographic work. The purpose of this panel is to bring together several interested individuals to initiate a Mars geographical research community. Panelists will summarize their own work with Mars and then, more generally, what they feel geography uniquely adds to an understanding of Mars. Discussion will explore possible forms for a Mars geographical community, ranging from a specialty group in the AAG and other societies to a network of geographers who can contribute specific expertise to particular research, educational, and policy projects.

Introduction to the Panel. -- Rodrigue

Geographers have become active contributors in the investigation of Mars and other extraterrestrial bodies, judging from author affiliations in research articles and conference presentations. They come with interests from across the discipline, and our panel today represents part of that range. We have physical geographers, represented today by Mark Bishop and Stephen Tooth, and human geographers, represented by Maria Lane and Jason Dittmer. I am an environmental geographer here to represent the regional geography of Mars and Mars in geographic education.

Each of us will discuss how we became involved with the study of Mars, what is specifically geographical about our work with Mars, what we think geographers may uniquely bring to the multidisciplinary investigation of our neighboring planet, and what Mars might bring to geography. The object is to see the range of interests Mars geographers have and begin developing a framework for this emerging discipline, the geography of Mars and, more broadly, extraterrestrial geographies. It is hoped that these discussions will lead to a formal network of extraterrestrial geographers, perhaps a specialty group within the AAG, and maybe a companion organization within LPSC. I have already established a Mars Geography Network web site at http://www.csulb.edu/geography/mars/ and a Google Group at http://groups.google.com/group/marsgeog/.

From a Hazards Project to the Regional Geography of Mars. -- Rodrigue

My own interest in Mars was a byproduct of my work in hazards. I do work on media rôles in shaping public hazards perceptions and setting policy agendas in risk management. I am interested in how risk assessment science and risk management policy interact and how risk management is impacted by public perceptions and activism. One of my projects was the controversy that flared up over the use of plutonium dioxide thermal generators on the Cassini-Huygens spacecraft and activist use of the then-new Internet to organize demonstrations and public pressure on the White House and Congress to abort the launch and later Earth flyby. In 2001, NASA became interested in my work and invited me to do a http://www.csulb.edu/~rodrigue/teleconpublic.html teleconference with five of its centers. They wanted to learn how better to manage somewhat similar controversies already brewing around the planned Mars Sample Return Lander, which was originally supposed to launch in 2008. They asked me to keep an eye on this controversy and to do a funded project later as launch approached. I agreed to do so and decided I had better become familiar with Mars as background to this planned study.

I began reading the research literature in JGR, Icarus, Science, and similar journals. Mars gradually became a real place for me, fascinating in the way it often entices one into thinking we understand landforms and processes from analogies with physical geography only to be pulled up short by a kind of "yes, but ..." quality. [ VIEWGRAPH: MOLA MAP ] If an ocean covered the Northern Lowlands, why then is its smooth, young floor andesitic, not basaltic? How are seemingly fluvial landscapes produced on a planet with such low atmospheric pressure that water can only alternate between ice and vapor? If water was so common in the early history of Mars, why is carbonate so sparse?

In the middle of all this, President Bush announced a new vision for space exploration, which ordered NASA to shift priorities from robotic explorations to preparing for human flight to the moon and Mars. As a result, the MSRL kept being delayed, and then it just vanished from the list of scheduled missions. With it went the project I was preparing.

Stranded with an increasingly detailed sense of Mars as a place, I decided to share my knowledge with our geography majors, rather than let it fade unused. Half the department was on sabbatical in 2006-07, so it became critical to offer a physical geography and GIScience course. Thus was born the Geography of Mars course and a new sense of urgency in learning about Mars!

One of my goals in the Geography of Mars class was to leave students with a vivid mental map of Mars and its major features. To do this, I developed a nested regionalization scheme inspired by the old orders of relief scheme so often seen in introductory physical geography textbooks. I'll discuss this in my paper on Thursday, in session 5451.

This very basic scheme represents an elementary geographical contribution to the study of Mars in that spatial contextualization is not well developed among the many case studies being done on Mars. I found it took me an awful lot of work to situate the case studies I read, which may be a peculiarly geographical discomfort. The orders of relief scheme, while referenced in introductory geography textbooks, no longer frames most research in geomorphology, and you never see it in introductory general geology textbooks. It was an idea useful for its time, 1916, when the surface of the US was perhaps as little known as Mars' is now. It is in that spirit that I think the orders of relief scheme may be useful now on Mars.

Noticing Other Geographers

While preparing for this class and working out this regional geography scheme, I began to notice that other geographers kept turning up among the authors on journal articles. I eventually began specifically recording their names and contact information, and the list grew to nearly 50 at last count! When I contacted everyone last summer, they, too, were blown away by the numbers of other geographers involved, and this panel is the result of that discussion. Unfortunately, many of our Mars geographer colleagues are at the Lunar and Planetary Science Conference, which is running simultaneously with the AAG this week.

The Geographic Contribution

What do geographers have to bring to the Mars research table? Obviously, our training in any of our subfields brings a strong sense of spatiality and regional context. So, many geographers on interdisciplinary teams work with GIS to interpret remotely sensed imagery and spectra. Another group of geographers I've noticed among authors bring their backgrounds in geomorphology to their teams, analyzing landforms that suggest fluvial processes involving overland and channelized flows, groundwater sapping, landslide and subsidence processes, glacial and periglacial processes, and æolian processes. The third group of geographers are human geographers interested in the intellectual history, politics, and cultural meaning of Mars exploration.

I think another rôle that we can play is bringing Mars and other planets into geographic education. Like other disciplines for which the other solar system bodies are on the edges of their traditional interests, such as geology and astronomy, geography needs to frame how the study of other planets fits into its mandate. It is clear that it presently fits three of the four geography definition clusters identified by Pattison in his classic 1963 statement: the spatial, the regional, and the physical. It is equally clear that the exploration agenda for Mars is even now bringing it within the compass of the human-environmental tradition in geography, too. The emergence of this fourth tradition may be what is drawing the attention of human geographers to Martian topics even now. So, bringing Mars into the geographic classroom might simply be an extension of our traditional concerns, and Mars geography classes could evolve into a valuable contribution of our departments to our institutions' curricula.

What Mars Offers to Geography

There is an opportunity cost, however, in bringing Martian content into ordinary geography classrooms: Discussion of the topic displaces some other topic that may be more canonical. Even so, Martian content can be used to enhance more canonical topics. Even as learning another language deepens your command of your own language, comparing Earth to Mars or other planets deepens our understanding of our home planet through counterpoint and contrast.

Mars (Planetary) Geography, Arid Lands Geomorphology, and Periglacial Environments. -- Bishop

I have a relatively long involvement with analog interpretation of planetary landforms and landscape. During the mid-1980's I pursued postgraduate work into the statistical and morphometric (classical methods) comparison of lunar craterform origin using terrestrial maar volcanoes and impact craters as benchmarks.

Following this I entered the field of æolian science where I examined the seasonal genesis and evolution of a small barchan dunefield in central Australia. This work was also an analog study and was devised to give a better understanding of æolian dynamics on Earth and Mars. However, it wasn't until recent years when I furthered my qualifications in GIS-based spatial statistics, and with the release of hi-resolution Mars imagery, did I fully realise the central röle that geographical data analysis could occupy for investigating landscape evolution and the measurement of surface and climate change for different planetary contexts.

Currently my work lies in the analog comparison of desert dune origin, maturity and evolution for the north polar region of Mars and major ergs of Earth such as the Ar Rub al Khali on the Arabian Peninsula, the Grand Ergs Oriental and Occidental of Algeria, and the Takla Makan, China. This work involves the understanding of the connections between glacial responses and climatic shifts through relatively recent geological time and the application to these of GIS-based spatial statistical models. Similarly, I am also involved with the deliberation of cone origin in the Tartarus Colles of low latitude Mars, and the geographic and geomorphic differences between this site and volcanoes and pingos on Earth. Again this work hinges on the röle of interpreting planetary-scale climatic change, and the distribution of volatiles in shaping the landscape and atmosphere using the tools of GISc.

What geography offers to the study of the planets and what the planets offer to geography

Geography gives to planetary science:

  1. Location or spatial context to events (all events have a geography although location is one of the least understood and investigated data types)

  2. A geographical bridge between:

    • the disciplines of physical geography (particularly geomorphology, climatology) and planetary science
    • the tool(s) of inquisition and data integration [GISc (remote sensing, geographic information systems, spatial statistics and GPS)]
    • field studies and `armchair' planetary science
    • geographic and attribute data
    • the modifiable areal unit problem (MAUP) and analysis
    • multi-disciplinary integration and collaboration

Planetary (Mars) science gives to geography:

    • an array of analogs for investigating the spatial and temporal evolution of planetary surfaces and atmospheres, inclusive of Earth
    • vast stores of (free) data
    • multi-disciplinary integration and collaboration
    • educational inspiration to future generations
    • a fresh perspective for both new and old ideas
In short, the opportunity exists for new and innovative investigations of planetary environments by using and adapting methods that are already well established within a geographer's skill set. From my viewpoint, the integration of geomorphology, climatology, remote sensing, geographical information systems, spatial statistical methods and GPS has created a multi- disciplined pathway for understanding planetary surfaces and atmospheres. This pathway by its very nature is geographical and from which a new paradigm, planetary geography, is emerging.

Mars, Earth, and Geomorphology. -- Tooth

This is an unprecedented era of data acquisition, with a rapidly expanding but diffuse volume of literature, some of which is published in traditional geomorphological outlets (e.g. Geomorphology, Geology) or the highest profile science journals (e.g. Science, Nature), but much of which is published in outlets unlikely to be consulted on a regular basis by many in the traditional geomorphological community (e.g. Icarus, Journal of Geophysical Research - Planets).

  1. Climate change and the history of aridity on Mars

    Key interrelated questions thus include: 1) which features of the Martian landscape are relics from the early wet climatic phase and which are the products of younger, arid climates?; 2) has the intensity of arid processes varied over time, resulting in periods of greater and lesser landsurface activity?; and 3) under the prevailing arid conditions, how active is the landsurface?

  2. How useful are Earth analogues for understanding the geomorphology of Mars?

    The search for analogous landforms or landscapes on Earth is fundamental to many Martian geomorphological studies

    It is more difficult to assess how the differences in Earth and Martian properties would influence the nature, magnitude, and frequency of geomorphological processes.

    At larger scales, the nature of some Martian landscapes is such that there may in fact be no suitable analogues on Earth.

  3. Process interpretations based on form

    The inherent dangers in such an approach will be clear to many geomorphologists familiar with the concept of equifinality, whereby different processes or different process combinations converge to the same (or similar) results (i.e., landforms or weathering features)

    1. Case study - amphitheatre-headed valleys

      Bedrock strength demands that seepage weathering precedes seepage erosion, and while this clearly can occur locally, the limited volumes of groundwater outflow would not be able to remove the large quantities of coarse debris that collapse onto the valley floor as the headwall retreats

    2. Case study - recent gullies

      Various imagery reveals that `bright gully' sediments have been deposited on Mars within the last few years. If source-region slopes are sufficiently steep, granular materials can exhibit fluid-like behaviour.

  4. Improvements in image resolution

    Mariner and Viking orbiters, which produced near-global coverage of the planet at resolutions typically between 200 and 300 m/pixel. Of necessity, process inferences were drawn from this rather meagre dataset. Two key lines of evidence cited as indicative of seepage erosion were:

    1. Apparent low Martian drainage densities of ~0.02/km (ie. a large drainage area per length of channel would be consistent with the relatively weak process of groundwater outflow-driven erosion) and

    2. Abundant valley networks that appeared to terminate at abrupt headwalls. More recent missions have provided higher resolution images (e.g., Mars Orbiter Camera on Mars Global Surveyor provides images at 1.4-6.0 m/pixel), increasing maximum estimated drainage densities to ~0.1/km, which approaches the range of drainage densities on Earth. These higher resolution images also show that instead of terminating at abrupt headwalls, many small tributaries in fact shallow gradually upvalley and merge progressively with their contributing uplands (Lamb et al., 2006 and references therein).

    Modifiable Areal Unit Problem???

  5. Arid modification of relic humid landscapes

    One of the key themes in Martian geomorphology is the long history of arid modification of landscapes formed under former, wetter conditions

    Many distinctive features on the Martian surface ( layered terrain in the Meridiani Planum region) are in part related to æolian deflation and deposition

    Spectacular fluvial landforms in the Elberswalde delta (e.g., sinuous distributary channels, overlapping depositional lobes, chute cutoffs, ridge-and-swale topography) now stand in inverted (positive) relief owing to preferential erosion and æolian deflation of the less resistant sediments surrounding the coarser-grained, possibly lithified, channel sedeiments

    In combination, such resurfacing processes have erased, buried or modified the form of many low-order tributaries and larger valleys, restricting the morphometry-based process inferences that can be made

  6. Interplay between (arid) geomorphological studies on Earth, Mars and other planetary bodies

    Are studies of Mars and other solid-surface, planetary bodies (e.g., large moons) just an interesting but essentially irrelevant curiosity, or can they contribute to the understanding of arid geomorphology, and geomorphology in general, on Earth?

    Planetary research has stimulated the search for and study of Earth analogues, thus contributing to improved understanding of arid landforms or landscapes that might otherwise have remained neglected or misinterpreted (e.g., amphitheatre-headed valleys).

    Satellite remote sensing has benefited geomorphology by encouraging a megascale approach to study

    The study of Mars and other planetary bodies stretches the imagination.

    Planetary science encourages one to `think big' (Sharpe, 1980) and to look for `outrageous' hypotheses of causationm because various large-scale landform assemblages and their formative processes are best understood in regional, hemispherical, or full planetary contexts, and this encourages one to think more about the workings of whole planet systems, as is evident in Mars-related research (e.g., Doran et al., 2004) and the emerging Earth System Science paradigm (e.g., Tooth, 2008; Macklin and Rice, 2008).

    If geomorphology is to become a complete science of landforms and landscapes, its subject matter is not appropriately limited to just the terrestrial portions of the Earth's surface. Much can be learned about geomorphology in general by comparison made possible by the discoveries from new worlds, such as unfamiliar or new processes and landforms with no Earth analogues

    Such wonder, excitement and enchantment is not just restricted to scientific circles but also extends into the wider public sphere, providing an ideal - but as yet underexploited - opportunity to promote geomorphology and physical geography.

  7. Research gaps

    Challenge now is to obtain a greater degree of chronological control to enable improved understanding of rates and timescales of planetary surface development

    There is also great potential for further interplay with Earth landscape studies that can be of mutual benefit

Historical/Cultural Research on Nineteenth Century Mars Science. -- Lane

Here is the general scope/direction of my intended comments:

  1. The changing cultural meanings of Mars science are as important as scientific/technological advances.

  2. Interpretive approaches drawn from science & technology studies can help us think about these cultural meanings.

  3. The "geography" of Mars science, in particular, may be a fruitful area of inquiry.

  4. My own historical-cultural research on late-nineteenth-century Mars science (for a forthcoming book with Chicago, Geographies of Mars) suggests numerous entrenched crosscurrents between geographical and "areographical" science that seemingly endure into the present.

The Geopolitics of Mars Exploration. -- Dittmer

Mars Panel Comments

  1. My interest stems from colonialism, geopolitics

    1. Fascination with ethics of colonialism in absence of life

    2. Not an expert on Mars - defer to panel, especially Maria, whose work first got me interested in this topic

  2. Connections to science fiction

    1. Longstanding tropes of projecting Earth onto Mars

      1. Post-Earth temporality
        • Similarities in formation process, former magnetic field, former plate tectonics, presence of water, volcanism
        • However, climate change 3.8 billion years ago

      2. Terraforming
        • Another way of projecting earth onto Mars in SF
        • Shaun Huston's analysis of Kim Stanley Robinson's trilogy: Environmental ethics, colonialism, identity and subjectivity
        • Colonialism and SF

    2. Current journalistic obsession with possibility of life on Mars

      1. Fuelled by 100 years+ of pulp fiction

      2. Heightens ethical questions raised in SF that will eventually be steam-rollered

    3. Resource competition and territorialisation (Astropolitik, Fraser Macdonald and the Corporal missile)

  3. Conclusions

    1. Over-focus in this discussion on Mars?

      1. Vast difficulties in human colonization (despite Bush)

      2. Will increasing understanding lead to waning in interest?

      3. Should include more theorization of geopolitics of near-earth space

    2. Titan: viewed by scientists as pre-Earth, waiting for sun's warmth

    3. Increase in technological capability might bring focus

This page maintained by C.M. Rodrigue
First placed on the web: 04/03/09
Last revised: 10/21/09