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Vasavada AR, Milavec TJ, Paige DA. Microcraters on Mars: Evidence for past climate variations. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/92je02942] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Strazzulla G, Leto G, Spinella F, Gomis O. Production of oxidants by ion irradiation of water/carbon dioxide frozen mixtures. ASTROBIOLOGY 2005; 5:612-21. [PMID: 16225434 DOI: 10.1089/ast.2005.5.612] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
We present new experimental results on the formation of oxidants, such as hydrogen peroxide, ozone, and carbonic acid, under ion irradiation of icy mixtures of water/carbon dioxide at different ratios and temperatures (16 and 80 K). Pure water ice layers and mixtures with carbon dioxide were irradiated by 200 keV He+ ions. We found that the CO(2)/H(2)O ratio progressively decreased to a value of about 0.1, the H(2)O(2) production increased with increasing CO(2) abundance at both 16 and 80 K, and the CO and H(2)CO(3) production increased with increasing CO(2) abundance at 16 K. At 80 K, the synthesis of CO was less efficient because of the high volatility of the molecule that partially sublimed from the target. The production of carbonic acid was connected with the production of CO(3). O(3) was detected only after ion irradiation of CO(2)-rich mixtures. The experimental results are discussed with regard to the relevance they may have in the production of an energy source for a europan or a martian biosphere.
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Affiliation(s)
- G Strazzulla
- INAF-Osservatorio Astrofisico, Via S. Sofia 78, I-95123 Catania, Italy.
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Hansen GB. Ultraviolet to near-infrared absorption spectrum of carbon dioxide ice from 0.174 to 1.8 μm. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2005je002531] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Bibring JP, Langevin Y, Poulet F, Gendrin A, Gondet B, Berthé M, Soufflot A, Drossart P, Combes M, Bellucci G, Moroz V, Mangold N, Schmitt B. Perennial water ice identified in the south polar cap of Mars. Nature 2004; 428:627-30. [PMID: 15024393 DOI: 10.1038/nature02461] [Citation(s) in RCA: 229] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Accepted: 03/05/2004] [Indexed: 11/09/2022]
Abstract
The inventory of water and carbon dioxide reservoirs on Mars are important clues for understanding the geological, climatic and potentially exobiological evolution of the planet. From the early mapping observation of the permanent ice caps on the martian poles, the northern cap was believed to be mainly composed of water ice, whereas the southern cap was thought to be constituted of carbon dioxide ice. However, recent missions (NASA missions Mars Global Surveyor and Odyssey) have revealed surface structures, altimetry profiles, underlying buried hydrogen, and temperatures of the south polar regions that are thermodynamically consistent with a mixture of surface water ice and carbon dioxide. Here we present the first direct identification and mapping of both carbon dioxide and water ice in the martian high southern latitudes, at a resolution of 2 km, during the local summer, when the extent of the polar ice is at its minimum. We observe that this south polar cap contains perennial water ice in extended areas: as a small admixture to carbon dioxide in the bright regions; associated with dust, without carbon dioxide, at the edges of this bright cap; and, unexpectedly, in large areas tens of kilometres away from the bright cap.
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Mitrofanov IG, Zuber MT, Litvak ML, Boynton WV, Smith DE, Drake D, Hamara D, Kozyrev AS, Sanin AB, Shinohara C, Saunders RS, Tretyakov V. CO2 snow depth and subsurface water-ice abundance in the northern hemisphere of Mars. Science 2003; 300:2081-4. [PMID: 12829779 DOI: 10.1126/science.1084350] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Observations of seasonal variations of neutron flux from the high-energy neutron detector (HEND) on Mars Odyssey combined with direct measurements of the thickness of condensed carbon dioxide by the Mars Orbiter Laser Altimeter (MOLA) on Mars Global Surveyor show a latitudinal dependence of northern winter deposition of carbon dioxide. The observations are also consistent with a shallow substrate consisting of a layer with water ice overlain by a layer of drier soil. The lower ice-rich layer contains between 50 and 75 weight % water, indicating that the shallow subsurface at northern polar latitudes on Mars is even more water rich than that in the south.
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Affiliation(s)
- I G Mitrofanov
- Space Research Institute, Russian Academy of Sciences, Moscow, 117997, Russia.
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Abstract
The Mars Odyssey Thermal Emission Imaging System (THEMIS) has discovered water ice exposed near the edge of Mars' southern perennial polar cap. The surface H2O ice was first observed by THEMIS as a region that was cooler than expected for dry soil at that latitude during the summer season. Diurnal and seasonal temperature trends derived from Mars Global Surveyor Thermal Emission Spectrometer observations indicate that there is H2O ice at the surface. Viking observations, and the few other relevant THEMIS observations, indicate that surface H2O ice may be widespread around and under the perennial CO2 cap.
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Affiliation(s)
- Timothy N Titus
- Branch of Astrogeology, U.S. Geological Survey, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA.
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Malin MC, Caplinger MA, Davis SD. Observational evidence for an active surface reservoir of solid carbon dioxide on Mars. Science 2001; 294:2146-8. [PMID: 11768358 DOI: 10.1126/science.1066416] [Citation(s) in RCA: 120] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
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 solid carbon dioxide. The erosion implies that this reservoir is not in equilibrium with the present environment and that global climate change is occurring on Mars.
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Affiliation(s)
- M C Malin
- Malin Space Science Systems, Post Office Box 910148, SanDiego, CA 92191-0148, USA
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Affiliation(s)
- D A Paige
- Department of Earth and Space Sciences, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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Schenk PM, Moore JM. Stereo topography of the south polar region of Mars: Volatile inventory and Mars Polar Lander landing site. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999je001054] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Kieffer HH, Titus TN, Mullins KF, Christensen PR. Mars south polar spring and summer behavior observed by TES: Seasonal cap evolution controlled by frost grain size. ACTA ACUST UNITED AC 2000. [DOI: 10.1029/1999je001136] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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11
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Herkenhoff KE, Vasavada AR. Dark material in the polar layered deposits and dunes on Mars. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1998je000589] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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12
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Mars CO2 Ice Polar Caps. ACTA ACUST UNITED AC 1998. [DOI: 10.1007/978-94-011-5252-5_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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13
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Hansen GB. The infrared absorption spectrum of carbon dioxide ice from 1.8 to 333 μm. ACTA ACUST UNITED AC 1997. [DOI: 10.1029/97je01875] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Jakosky BM, Henderson BG, Mellon MT. Chaotic obliquity and the nature of the Martian climate. ACTA ACUST UNITED AC 1995. [DOI: 10.1029/94je02801] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Paige DA, Keegan KD. Thermal and albedo mapping of the polar regions of Mars using Viking thermal mapper observations: 2. South polar region. ACTA ACUST UNITED AC 1994. [DOI: 10.1029/93je03429] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McCleese DJ, Haskins RD, Schofield JT, Zurek RW, Leovy CB, Paige DA, Taylor FW. Atmosphere and climate studies of Mars using the Mars Observer pressure modulator infrared radiometer. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92je00539] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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17
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Christensen PR, Anderson DL, Chase SC, Clark RN, Kieffer HH, Malin MC, Pearl JC, Carpenter J, Bandiera N, Brown FG, Silverman S. Thermal emission spectrometer experiment: Mars Observer mission. ACTA ACUST UNITED AC 1992. [DOI: 10.1029/92je00453] [Citation(s) in RCA: 230] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abstract
Full disk images of Mars have been obtained with the use of the Very Large Array (VLA) to map the radar reflected flux density. The transmitter system was the 70-m antenna of the Deep Space Network at Goldstone, California. The surface of Mars was illuminated with continuous wave radiation at a wavelength of 3,5 cm. The reflected energy was mapped in individual 12-minute snapshots with the VLA in its largest configuration; fringe spacings as small as 67 km were obtained. The images reveal near-surface features including a region in the Tharsis volcano area, over 2000 km in east-west extent, that displayed no echo to the very low level of the radar system noise. The feature, called Stealth, is interpreted as a deposit of dust or ash with a density less than about 0.5 gram per cubic centimeter and free of rocks larger than 1 cm across. The deposit must be several meters thick and may be much deeper. The strongest reflecting geological feature was the south polar ice cap, which was reduced in size to the residual south polar ice cap at the season of observation. The cap image is interpreted as arising from nearly pure CO(2) or H(2)O ice with a small amount of martian dust (less than 2 percent by volume) and a depth greater than 2 to 5 m. Only one anomalous reflecting feature was identified outside of the Tharsis region, although the Elysium region was poorly sampled in this experiment and the north pole was not visible from Earth.
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Abstract
Mars is believed to be lifeless, but it may be possible to transform it into a planet suitable for habitation by plants, and conceivably humans. The success of such an enterprise would depend on the abundance, distribution and form of materials on the planet that could provide carbon dioxide, water and nitrogen.
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Affiliation(s)
- C P McKay
- Space Science Division, NASA Ames Research Center, Moffett Field, California 94035, USA
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