The State and Future of Mars Polar Science and Exploration

Icarus, Vol. 144, No. 2, p. 210-242, 2000 

S.M. Clifford,
Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, Texas 77058, USA.
D. Crisp, S.E. Smrekar, R.W. Zurek, J.M. Cameron, J.A. Cutts, D.J. McCleese, J.J. Plaut
Jet Propulsion Laboratory, Pasadena, California 91109, USA.
D.A. Fisher
Terrain Science Division, Geological Survey of Canada, Ottawa, Ontario K1A 0E8, Canada.
K.E. Herkenhoff, W.M. Calvin, J.S. Kargel, H.H. Kieffer, K.L. Tanaka
U.S. Geological Survey, Flagstaff, Arizona 86001, USA.
P.C. Thomas
Department of Astronomy, Cornell University, Ithaca, New York 14853, USA.
D.D. Wynn-Williams
British Antarctic Survey, Natural Environmental Research Council, Cambridge CB3 0ET, United Kingdom.
J.R. Barnes
College of Oceanic and Atmospheric Sciences, Oregon State University, Oregon 97331, USA.
B.G. Bills, D.E. Smith, H.J. Zwally
Geodynamics Branch, NASA Goddard Space Flight Center, Greenbelt, Maryland 20771, USA.
E.W. Blake
Icefield Instruments Inc., Whitehorse, Yukon Canada, Y1A 5H4, Canada.
M.H. Carr
U.S. Geological Survey, Menlo Park, California 94025, USA.
P.R. Christensen, J.D. Farmer
Department of Geology, Arizona State University, Tempe, Arizona 85287, USA.
B.C. Clark
Lockheed Martin Astronautics, Denver, Colorado 8020, USA.
G.D. Clow
U.S. Geological Survey, Denver Federal Center, Denver, Colorado 80225, USA.
D. Dahl-Jensen, J. Larsen
Departement of Geophysics, The Niels Bohr Institute of Astronomy, Physics and Geophysics, University of Copenhagen.
W.B. Durham
Lawrence Livermore National Laboratory, University of California-Berkeley, Livermore, California 94550, USA.
F.P. Fanale
Hawaii Institute of Geophysics and Planetology, Honolulu, Hawaii 96822, USA.
F. Forget
Laboratoire de Météorologie Dynamique du C.N.R.S., Université de Paris 6, F-75252 Paris Cedex 05, France.
K. Gotto-Azuma
Nagaoka Institute of Snow and Ice Studies NIED, 187-16 Suyoshi Nagaoka Niigata, Japan.
R. Grard
European Space Agency/ESTEC, NL-2200 AG Noordwijk, The Netherlands.
R.M. Haberle, C.R. Stoker, A. Zent
Space Sciences Division, NASA Ames Research Center, Moffett Field, California 94035, USA.
W. Harrison
Geophysical Institute, University of Alaska-Fairbanks, 903 Koyukuk Drive, Fairbanks, Alaska 99775, USA.
R. Harvey
Department of Geological Sciences, Case Western Reserve University, Cleveland, Ohio 44106, USA.
A.D. Howard
Department of Environmental Science, University of Virginia, Charlottesville, Virginia 22903, USA.
A.P. Ingersoll, B. Murray
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, USA.
P.B. James
Department of Physics and Astronomy, University of Toledo, Ohio 43606, USA.
K. Lepper
Environmental Sciences Program, Department of Physics, Oklahoma State University, Oklahoma 74078, USA.
M.C. Malin
Malin Space Science Systems, Inc., San Diego, California 92191, USA.
J.F. Nye
Department of Physics, H.H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL, United Kingdom.
D.A. Paige
Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, California 90095, USA.
S.R. Platt
Snow and Ice Research Group, University of Nebraska-Lincoln, Lincoln, Nebraska 68583, USA.
N. Reeh
Danish Center for Remote Sensing, Technical University of Denmark, DK-2800 Lyngby Denmark.
J.W. Rice
Lunar and Planetary Laboratory, University of Arizona, Tucson, Arizona 85721, USA.
E. Mosley-Thompson
Byrd Polar Research Center, Ohio State University, Columbus, Ohio 43210, USA.
T. Thorsteinsson
Alfred-Wegener-Institut für Polar- und Meeresforschung, Columbusstrasse, D-27568 Bremerhaven, Germany.
S.E. Wood
Department of Atmospheric Sciences, University of Washington, Seattle, Washington 98195, USA.
M.T. Zuber
Department of Earth Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.

ABSTRACT.
As the planet's principal cold traps, the martian polar regions have accumulated extensive mantles of ice and dust that cover individual areas of ~10⁶ km² and total as much as 3-4 km thick. From the scarcity of superposed craters on their surface, these layered deposits are thought to be comparatively young-preserving a record of the seasonal and climatic cycling of atmospheric CO₂, H₂O, and dust over the past ~10⁵-10⁸ years. For this reason, the martian polar deposits may serve as a Rosetta Stone for understanding the geologic and climatic history of the planet - documenting variations in insolation (due to quasiperiodic oscillations in the planet's obliquity and orbital elements), volatile mass balance, atmospheric composition, dust storm activity, volcanic eruptions, large impacts, catastrophic floods, solar luminosity, supernovae, and perhaps even a record of microbial life. Beyond their scientific value, the polar regions may soon prove important for another reason - providing a valuable and accessible reservoir of water to support the long-term human exploration of Mars. In this paper we assess the current state of Mars polar research, identify the key questions that motivate the exploration of the polar regions, discuss the extent to which current missions will address these questions, and speculate about what additional capabilities and investigations may be required to address the issues that remain outstanding.