Observational Evidence for an Active Surface Reservoir of Solid Carbon Dioxide on Mars

  title={Observational Evidence for an Active Surface Reservoir of Solid Carbon Dioxide on Mars},
  author={Michael C. Malin and Michael A. Caplinger and Scott D. Davis},
  pages={2146 - 2148}
High-resolution images of the south polar residual cap of Mars acquired in 1999 and 2001 show changes in the configuration of pits, intervening ridges, and isolated mounds. Escarpments have retreated 1 to 3 meters in 1 martian year, changes that are an order of magnitude larger than can be explained by the sublimation of water ice, but close to what is expected for sublimation of carbon dioxide ice. These observations support a 35-year-old conjecture that Mars has a large surface reservoir of… 
A Sublimation Model for Martian South Polar Ice Features
This work argues that a carbon dioxide ice layer about 8 meters thick is being etched away to reveal water ice underneath on Mars, consistent with thermal infrared data from the Mars Odyssey mission.
Water at the poles and in permafrost regions of mars
The poles and mid-latitudes of Mars contain abundant water in ice caps, thick sequences of ice-rich layers, and mantles of snow. The volume of the known reservoir is ≥5 x 106 km3, corresponding to a
Active Mars: A Dynamic World
Mars exhibits diverse surface changes at all latitudes and all seasons. Active processes include impact cratering, aeolian sand and dust transport, a variety of slope processes, changes in polar
Spiders: water-driven erosive structures in the southern hemisphere of Mars.
It is proposed that a number of the erosive features identified in Inca City, among them spiders, result from the seasonal melting of aqueous salty solutions.
Martian climatic events on timescales of centuries: Evidence from feature morphology in the residual south polar ice cap
Flat‐floored, quasi‐circular depressions on the southern residual cap of Mars have been observed to expand rapidly. Analysis of the size distribution combined with modeling of the growth process
Density of Mars' South Polar Layered Deposits
The results demonstrate that the deposits of south polar layered deposits are probably composed of relatively clean water ice and also refine the martian surface-water inventory.
Exposed Water Ice Discovered near the South Pole of Mars
The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap, indicating that surface H2O ice may be widespread around and under the perennial CO2 cap.


Evidence for recent groundwater seepage and surface runoff on Mars.
Gullies within the walls of a very small number of impact craters, south polar pits, and two of the larger martian valleys display geomorphic features that can be explained by processes associated with groundwater seepage and surface runoff.
The global topography of Mars and implications for surface evolution.
Elevations measured by the Mars Orbiter Laser Altimeter have yielded a high-accuracy global map of the topography of Mars. Dominant features include the low northern hemisphere, the Tharsis province,
Polar Volatiles on Mars—Theory versus Observation
The residual frost caps of Mars are probably water-ice and a permanent reservoir of solid CO2 is also probably present within the north residual cap, which may comprise a mass of CO2 some two to five times that of the present atmosphere of Mars.
Global seasonal variation of water vapor on Mars and the implications for permafrost
Observations of the global distribution and seasonal variation of the Martian atmospheric water vapor have been made from the Viking orbiters for a continuous period covering a complete Martian year.
Climatic variations on Mars: 2. Evolution of carbon dioxide atmosphere and polar caps
The long-term variations in the atmospheric pressure and the polar cap temperature of Mars resulting from the obliquity oscillations (presented by W. R. Ward, 1974) are discussed. In performing these
Mariner 9 observations of the south polar cap of Mars: Evidence for residual CO2 frost
The first spacecraft observations of the south residual polar cap of Mars were obtained by the Mariner 9 orbiter during the Martian southern summer season, 1971–1972. Analyses of Viking orbiter
The state and future of Mars polar science and exploration.
The current state of Mars polar research is assessed, the key questions that motivate the exploration of the polar regions are identified, the extent to which current missions will address these questions are discussed, and what additional capabilities and investigations may be required to address the issues that remain outstanding are speculated.
Annual Heat Balance of Martian Polar Caps: Viking Observations
The Infrared Thermal Mappers aboard the two Viking orbiters obtained solar reflectance and infrared emission measurements of the Martian north and south polar regions during an entire Mars year to determine annual radiation budgets and constrain spring season surface and atmospheric properties with the aid of a polar radiative model.
Topography of the polar layered deposits of Mars
Synthesis of polar topographic data derived from the Mariner 9 radio occultation, ultraviolet spectrometer, and television imaging experiments provides new information on the behavior of polar
Behavior of Carbon Dioxide and Other Volatiles on Mars
We have found that a rather simple thermal model of the Martian surface, in combination with current observations of the atmospheric composition, points strongly toward the conclusion that the polar