Common surface features of Mars

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The common surface features of Mars include dark slope streaks, dust devil tracks, sand dunes, Medusae Fossae Formation, fretted terrain, layers, gullies, glaciers, scalloped topography, chaos terrain, possible ancient rivers, pedestal craters, brain terrain, and ring mold craters.

Slope streaks[edit]

When occurring near the top of a dune, dark sand may cascade down the dune leaving dark surface streaks -- streaks that might appear at first to be trees standing in front of the lighter regions.

A new phenomenon known as slope streaks has been uncovered by the HiRISE camera on the Mars Reconnaissance Orbiter. These features appear on crater walls and other slopes, and they are thin and many hundreds of metres long. The streaks have been observed to grow slowly over the course of a year or so, always beginning at a point source. Newly formed streaks are dark in colour but fade as they age until white. The cause is unknown, but theories range from dry dust avalanches (the favoured theory) to brine seepage.[1]

Examples of dark slope streaks from various parts of Mars are shown below. Click on image to get a better view.

Dust devil tracks[edit]

Many areas on Mars experience the passage of giant dust devils. A thin coating of fine bright dust covers most of the Martian surface. When a dust devil travels by, it blows away the coating and exposes the underlying dark surface. These dust devils have been seen both from the ground and from orbit. They have even blown the dust off the solar panels of the two Rovers on Mars, thereby greatly extending their lives.[2] The twin Rovers were designed to last for 3 months; instead, they have lasted eleven years and are still going. The pattern of the tracks have been shown to change every few months.[3]

Layers[edit]

Many places on Mars show rocks arranged in layers. Rock can form layers in a variety of ways. Volcanoes, wind, or water can produce layers.[4]

A detailed discussion of layering with many Martian examples can be found in Sedimentary Geology of Mars.[5] Layers can be hardened by the action of groundwater. Martian ground water probably moved hundreds of kilometers, and in the process it dissolved many minerals from the rock it passed through. When ground water surfaces in low areas containing sediments, water evaporates in the thin atmosphere and leaves behind minerals as deposits and/or cementing agents. Consequently, layers of dust could not later easily erode away since they were cemented together.

,

Sand dunes[edit]

Many locations on Mars have sand dunes. An erg (or sand sea), made up of aeolian dune fields referred to as the Circumpolar Dune Field[6] surrounds most of the north polar cap.[7] The dunes are covered by a seasonal carbon dioxide frost that forms in early autumn and remains until late spring.[7] Many martian dunes strongly resemble terrestrial dunes but images acquired by the High-Resolution Imaging Science Experiment on the Mars Reconnaissance Orbiter have shown that martian dunes in the north polar region are subject to modification via grainflow triggered by seasonal CO2 sublimation, a process not seen on Earth.[8] Many dunes are black because they are derived from the dark volcanic rock basalt. Extraterrestrial sand seas such as those found on Mars are referred to as "undae" from the Latin for waves.

Gullies[edit]

Martian gullies are small, incised networks of narrow channels and their associated downslope sediment deposits, found on the planet of Mars. They are named for their resemblance to terrestrial gullies. First discovered on images from Mars Global Surveyor, they occur on steep slopes, especially on the walls of craters. Usually, each gully has a dendritic alcove at its head, a fan-shaped apron at its base, and a single thread of incised channel linking the two, giving the whole gully an hourglass shape.[9] They are believed to be relatively young because they have few, if any craters.

On the basis of their form, aspects, positions, and location amongst and apparent interaction with features thought to be rich in water ice, many researchers believed that the processes carving the gullies involve liquid water. However, this remains a topic of active research.

Main article: Martian gullies

Medusae Fossae Formation[edit]

The Medusae Fossae Formation is a soft, easily eroded deposit that extends for nearly 1,000 km along the equator of Mars. Sometimes the formation appears as a smooth and gently undulating surface; however, in places it is wind-sculpted into ridges and grooves.[10] Radar imaging has suggested that the region may contain either extremely porous rock (for example volcanic ash) or deep layers of glacier-like ice deposits amounting to about the same quantity as is stored in Mars' south polar cap.[11][12]

The lower portion (member) of Medusae Fossae Formation contains many patterns and shapes that are thought to be the remains of streams. It is believed that streams formed valleys that were filled and became resistant to erosion by cementaion of minerals or by the gathering of a coarse covering layer. These inverted stream beds are sometimes called sinuous ridges or raised curvilinear features. They may be a kilometer or so in length. Their height ranges from a meter to greater than 10 meters, while the width of the narrow ones is less than 10 meters.[13]

The wind has eroded the surface of the formation into a series of linear ridges called yardangs. These ridges generally point in the direction of the prevailing winds that carved them and demonstrate the erosive power of martian winds. The easily eroded nature of the Medusae Fossae Formation suggests that it is composed of weakly cemented particles, and was most likely formed by the deposition of wind-blown dust or volcanic ash. Layers are seen in parts of the formation. A resistant caprock on the top of yardangs has been observed in Viking,[14] Mars Global Surveyor,[15] and HiRISE photos.[16] Very few impact craters are visible throughout the area so the surface is relatively young.[17]

Yardangs[edit]

Yardangs are common in some regions on Mars, especially in what's called the "Medusae Fossae Formation." This formation is found in the Amazonis quadrangle and near the equator.[18] They are formed by the action of wind on sand sized particles; hence they often point in the direction that the winds were blowing when they were formed.[19] Because they exhibit very few impact craters they are believed to be relatively young.[17]

Main article: Yardangs on Mars

,

Fretted terrain[edit]

Fretted terrain is a type of surface feature common to certain areas of Mars and discovered in Mariner 9 images. It lies between two different surfaces. The surface of Mars can be divided into two parts: low, young, uncratered plains that cover most of the northern hemisphere, and high-standing, old, heavily cratered areas that cover the southern hemisphere and a small part of the northern hemisphere. Between these two zones is the fretted terrain, containing a complicated mix of cliffs, mesas, buttes, and straight-walled and sinuous canyons. Fretted terrain contains smooth, flat lowlands along with steep cliffs. The scarps or cliffs are usually 1 to 2 km high. Channels in the area have wide, flat floors and steep walls.[20] Fretted terrain is most common in northern Arabia, between latitudes 30°N and 50°N and longitudes 270°W and 360°W.[21] Parts of the fretted terrain are called Deuteronilus Mensae and Protonilus Mensae.

In fretted terrain, the land seems to transition from narrow straight valleys to isolated mesas. Most of the mesas are surrounded by forms that have been called a variety of names (circum-mesa aprons, debris aprons, rock glaciers, and lobate debris aprons).[22] At first they appeared to resemble rock glaciers on Earth, but scientists could not be sure. Eventually, proof of their true nature was discovered by radar studies with the Mars Reconnaissance Orbiter and showed that they contain pure water ice covered with a thin layer of rocks that insulated the ice.[23][24][25][26][27][28]

In addition to rock covered glaciers around mesas, the region has many steep-walled valleys with lineations—ridges and grooves—on their floors. The material comprising these valley floors is called lineated valley fill. In some of the best images taken by the Viking Orbiters, some of the valley fill appeared to resemble alpine glaciers on Earth. Given this similarity, some scientists assumed that the lineations on these valley floors might have formed by flow of ice in (and perhaps through) these canyons and valleys. Today, it is generally agreed that glacial flow caused the lineations.

Glaciers[edit]

Glaciers, loosely defined as patches of currently or recently flowing ice, are thought to be present across large but restricted areas of the modern Martian surface, and are inferred to have been more widely distributed at times in the past.[29][30]

Main article: Glaciers on Mars
Martian glacier moving down a valley, as seen by HiRISE under HiWish program.

|

Concentric crater fill[edit]

Concentric crater fill, like lobate debris aprons and lineated valley fill, is believed to be ice-rich.[31] Based on accurate topography measures of height at different points in these craters and calculations of how deep the craters should be based on their diameters, it is thought that the craters are 80% filled with mostly ice.[32][33][34][35] That is, they hold hundreds of meters of material that probably consists of ice with a few tens of meters of surface debris.[36][37] The ice accumulated in the crater from snowfall in previous climates.[38][39][40] Recent modeling suggests that concentric crater fill develops over many cycles in which snow is deposited, then moves into the crater. Once inside the crater, shade and dust preserve the snow. The snow changes to ice. The many concentric lines are created by the many cycles of snow accumulation. Generally snow accumulates whenever the axial tilt reaches 35 degrees.[41]

Mesas[edit]

Chaos terrain[edit]

Chaos terrain is believed to be associated with the release of huge amounts of water. The chaotic features may have collapsed when water came out of the surface. Martian outflow channels commonly begin with a Chaos region. A chaotic region can be recognized by a tangle of mesas, buttes, and hills, all chopped through with valleys which in places look almost patterned. Some parts of this chaotic area have not collapsed completely—they are still formed into large mesas, so they may still contain water ice.[42] Chaotic terrain occurs in numerous locations on Mars, and always gives the strong impression that something abruptly disturbed the ground. Chaos regions formed long ago. By counting craters (more craters in any given area means an older surface) and by studying the valleys' relations with other geological features, scientists have concluded the channels formed 2.0 to 3.8 billion years ago.[43]

Upper Plains Unit[edit]

Remnants of a 50-100 meter thick mantling, called the upper plains unit, has been discovered in the mid-latitudes of Mars. First investigated in the Deuteronilus Mensae region, but it occurs in other places as well. The remnants consist of sets of dipping layers in craters and along mesas.[44] Sets of dipping layers may be of various sizes and shapes—some look like Aztec pyramids from Central America.

This unit also degrades into brain terrain. Brain terrain is a region of maze-like ridges 3–5 meters high. Some ridges may consist of an ice core, so they may be sources of water for future colonists.

Some regions of the upper plains unit display large fractures and troughs with raised rims; such regions are called ribbed upper plains. Fractures are believed to have started with small cracks from stresses. Stress is suggested to initiate the fracture process since ribbed upper plains are common when debris aprons come together or near the edge of debris aprons—such sites would generate compressional stresses. Cracks exposed more surfaces, and consequently more ice in the material sublimates into the planet’s thin atmosphere. Eventually, small cracks become large canyons or troughs. Small cracks often contain small pits and chains of pits; these are thought to be from sublimation of ice in the ground.[45][46] Large areas of the Martian surface are loaded with ice that is protected by a meters thick layer of dust and other material. However, if cracks appear, a fresh surface will expose ice to the thin atmosphere.[47][48] In a short time, the ice will disappear into the cold, thin atmosphere in a process called sublimation. Dry ice behaves in a similar fashion on the Earth. On Mars sublimation has been observed when the Phoenix lander uncovered chunks of ice that disappeared in a few days.[49][50] In addition, HiRISE has seen fresh craters with ice at the bottom. After a time, HiRISE saw the ice deposit disappear.[51]

The upper plains unit is thought to have fallen from the sky. It drapes various surfaces, as if it fell evenly. As is the case for other mantle deposits, the upper plains unit has layers, is fine-grained, and is ice-rich. It is widespread; it does not seem to have a point source. The surface appearance of some regions of Mars is due to how this unit has degraded. It is a major cause of the surface appearance of lobate debris aprons.[46] The layering of the upper plains mantling unit and other mantling units are believed to be caused by major changes in the planet’s climate. Models predict that the obliquity or tilt of the rotational axis has varied from its present 25 degrees to maybe over 80 degrees over geological time. Periods of high tilt will cause the ice in the polar caps to be redistributed and change the amount of dust in the atmosphere.[52][53][54]

Latitude dependent mantle[edit]

Much of the Martian surface is covered with a thick ice-rich, mantle layer that has fallen from the sky a number of times in the past.[55][56][57] In some places a number of layers are visible in the mantle.

It fell as snow and ice-coated dust. There is good evidence that this mantle is ice-rich. The shapes of the polygons common on many surfaces suggest ice-rich soil. High levels of hydrogen (probably from water) have been found with Mars Odyssey.[58][59][60][61][62] Thermal measurements from orbit suggest ice.[63][64] The Phoenix (spacecraft) discovered water ice with made direct observations since it landed in a field of polygons.[65][66] In fact, its landing rockets exposed pure ice. Theory had predicted that ice would be found under a few cm of soil. This mantle layer is called "latitude dependent mantle" because its occurrence is related to the latitude. It is this mantle that cracks and then forms polygonal ground. This cracking of ice-rich ground is predicted based on physical processes.[67][68] [69][70][71][72][73]

,

Polygonal patterned ground[edit]

Polygonal, patterned ground is quite common in some regions of Mars.[74][75][76][77][78][79][80] It is commonly believed to be caused by the sublimation of ice from the ground. Sublimation is the direct change of solid ice to a gas. This is similar to what happens to dry ice on the Earth. Places on Mars that display polygonal ground may indicate where future colonists can find water ice. Patterned ground forms in a mantle layer, called latitude dependent mantle, that fell from the sky when the climate was different.[55][56][81][82]

,

Scalloped topography[edit]

Scalloped topography is common in the mid-latitudes of Mars, between 45° and 60° north and south. It is particularly prominent in the region of Utopia Planitia[83][84] in the northern hemisphere and in the region of Peneus and Amphitrites Patera[85][86] in the southern hemisphere. Such topography consists of shallow, rimless depressions with scalloped edges, commonly referred to as "scalloped depressions" or simply "scallops". Scalloped depressions can be isolated or clustered and sometimes seem to coalesce. A typical scalloped depression displays a gentle equator-facing slope and a steeper pole-facing scarp. This topographic asymmetry is probably due to differences in insolation. Scalloped depressions are believed to form from the removal of subsurface material, possibly interstitial ice, by sublimation. This process may still be happening at present.[87]

Ancient rivers?[edit]

There is great deal of evidence that water once flowed in river valleys on Mars. Pictures from orbit show winding valleys, branched valleys, and even meanders with oxbow lakes.[88] Some are visible in the pictures below.

Streamlined shapes[edit]

Streamlined shapes represent more evidence of past flowing water on Mars. Water shaped features into streamlined shapes.

Deltas[edit]

Pedestal crater[edit]

Pedestal craters are believed to be caused by a crater's ejecta protecting the material beneath it from eroding. The underlying material is probably ice-rich; hence these craters indicate where and how much ice was present in the ground.[89][90][91][92]

Main article: Pedestal crater

Halo Craters[edit]

Boulders[edit]

Brain terrain[edit]

Brain terrain is a feature of the Martian surface, consisting of complex ridges found on lobate debris aprons, lineated valley fill and concentric crater fill. It is so named because it suggests the ridges on the surface of the human brain. Wide ridges are called closed-cell brain terrain, and the less common narrow ridges are called open-cell brain terrain.[94] It is thought that the wide closed-cell terrain contains a core of ice, and when the ice disappears the center of the wide ridge collapses to produce the narrow ridges of the open-cell brain terrain.

Main article: Brain terrain

Ring mold craters[edit]

Ring mold craters are believed to be formed from asteroid impacts into ground that has an underlying layer of ice. The impact produces an rebound of the ice layer to form a "ring-mold" shape.

Main article: Ring mold crater

,

Rootless Cones[edit]

So-called "Rootless cones" are caused by explosions of lava with ground ice under the flow. The ice melts and turns into a vapor that expands in an explosion that produces a cone or ring. Featureslike these are found in Iceland, when lavas cover water-saturated substrates.[95][96][97]

Mud volcanoes[edit]

Some features look like volcanoes. Some of them may be mud volcanoes where pressurized mud is forced upward forming cones. These features may be places to look for life as they bring to the surface possible life that has been protected from radiation.

Lava flows[edit]

Linear Ridge Networks[edit]

Linear ridge networks are found in various places on Mars in and around craters.[98] Ridges often appear as mostly straight segments that intersect in a lattice-like manner. They are hundreds of meters long, tens of meters high, and several meters wide. It is thought that impacts created fractures in the surface, these fractures later acted as channels for fluids. Fluids cemented the structures. With the passage of time, surrounding material was eroded away, thereby leaving hard ridges behind. Since the ridges occur in locations with clay, these formations could serve as a marker for clay which requires water for its formation.[99][100][101]

Fractures forming blocks[edit]

In places large fractures break up surfaces. Sometimes straight edges are formed and large cubes are created by the fractures.

Defrosting[edit]

In the spring, various shapes appear because frost is disappearing from the surface, exposing the underling dark soil. Also, in some places dust is blown out of in geyser-like eruptions that are sometimes called "spiders." If a wind is blowing, the material creates a long, dark streak or fan.

Main article: Geyser (Mars)

See also[edit]

References[edit]

  1. ^ "Newly-Formed Slope Streaks". NASA. Retrieved 2007-03-16. 
  2. ^ "Mars Exploration Rover Mission: Press Release Images: Spirit". Marsrovers.jpl.nasa.gov. Retrieved 2012-01-16. 
  3. ^ https://web.archive.org/web/20111028015730/http://mars.jpl.nasa.gov/spotlight/kenEdgett.html. Archived from the original on October 28, 2011. Retrieved January 19, 2012.  Missing or empty |title= (help)
  4. ^ "HiRISE | High Resolution Imaging Science Experiment". Hirise.lpl.arizona.edu?psp_008437_1750. Retrieved 2012-08-04. 
  5. ^ Grotzinger, J. and R. Milliken (eds.). 2012. Sedimentary Geology of Mars. SEPM.
  6. ^ Massé, M.; Bourgeois, O; Le Mouélic, S.; Verpoorter, C.; Le Deit, L. (March 2011). "Distribution and Origin of Polar Gypsum on Mars" (PDF). 42nd Lunar and Planetary Science Conference. Lunar and Planetary Institute. Retrieved 2015-02-20. 
  7. ^ a b Schatz, Volker; H. Tsoar; K. S. Edgett; E. J. R. Parteli; H. J. Herrmann (2006). "Evidence for indurated sand dunes in the Martian north polar region" (PDF). Journal of Geophysical Research. 111 (E04006). Bibcode:2006JGRE..11104006S. doi:10.1029/2005JE002514. 
  8. ^ Hansen, C. J.; Bourke, M.; Bridges, N. T.; Byrne, S.; Colon, C.; Diniega, S.; Dundas, C.; Herkenhoff, K.; McEwen, A.; Mellon, M.; Portyankina, G.; Thomas, N. (4 February 2011). "Seasonal Erosion and Restoration of Mars' Northern Polar Dunes" (PDF). Science. 331 (6017): 575–578. Bibcode:2011Sci...331..575H. doi:10.1126/science.1197636. PMID 21292976. Retrieved 2015-02-20. 
  9. ^ Malin, M., Edgett, K. 2000. Evidence for recent groundwater seepage and surface runoff on Mars. Science 288, 2330–2335.
  10. ^ Fraser Cain (2005-03-29). "Medusa Fossae Region on Mars". Universetoday.com. Retrieved 2012-01-16. 
  11. ^ Shiga, David (1 November 2007). "Vast amount of water ice may lie on Martian equator". New Scientist Space. Retrieved 20 January 2011. 
  12. ^ Watters, T. R.; Campbell, B.; Carter, L.; Leuschen, C. J.; Plaut, J. J.; Picardi, G.; Orosei, R.; Safaeinili, A.; et al. (2007). "Radar Sounding of the Medusae Fossae Formation Mars: Equatorial Ice or Dry, Low-Density Deposits?". Science. 318 (5853): 1125–8. Bibcode:2007Sci...318.1125W. doi:10.1126/science.1148112. PMID 17975034. 
  13. ^ Zimbelman, James R.; Griffin, Lora J. (2010). "HiRISE images of yardangs and sinuous ridges in the lower member of the Medusae Fossae Formation, Mars". Icarus. 205 (1): 198–210. Bibcode:2010Icar..205..198Z. doi:10.1016/j.icarus.2009.04.003. 
  14. ^ Scott, David H.; Tanaka, Kenneth L. (1982). "Ignimbrites of Amazonis Planitia Region of Mars". Journal of Geophysical Research. 87 (B2): 1179–1190. Bibcode:1982JGR....87.1179S. doi:10.1029/JB087iB02p01179. 
  15. ^ Malin, MC; Carr, MH; Danielson, GE; Davies, ME; Hartmann, WK; Ingersoll, AP; James, PB; Masursky, H; et al. (March 1998). "Early views of the martian surface from the Mars Orbiter Camera of Mars Global Surveyor". Science. 279 (5357): 1681–5. Bibcode:1998Sci...279.1681M. doi:10.1126/science.279.5357.1681. PMID 9497280. 
  16. ^ Mandt, Kathleen E.; De Silva, Shanaka L.; Zimbelman, James R.; Crown, David A. (2008). "The origin of the Medusae Fossae Formation, Mars: Insights from a synoptic approach". Journal of Geophysical Research. 113 (E12): 12011. Bibcode:2008JGRE..11312011M. doi:10.1029/2008JE003076. 
  17. ^ a b http://themis.asu.edu/zoom-20020416a
  18. ^ SAO/NASA ADS Astronomy Abstract Service: Yardangs on Mars
  19. ^ http://www.esa.int/Our_Activities/Space_Science/Mars_Express/Yardangs_on_Mars
  20. ^ Strom, R.G.; Croft, S.K.; Barlow, N.G. (1992). "The Martian Impact Cratering Record". In Kieffer, H.H.; Jakosky, B.M.; Snyder, C.W.; Matthews, M.S. Mars. Tucson: University of Arizona Press. pp. 384–385. ISBN 978-0-8165-1257-7. 
  21. ^ "Catalog Page for PIA01502". Photojournal.jpl.nasa.gov. Retrieved 2012-01-16. 
  22. ^ http://www.lpi.usra.edu/meetings/lpsc2000/pdf/1053.pdf
  23. ^ Head, J.; Neukum, G.; Jaumann, R.; Hiesinger, H.; Hauber, E.; Carr, M.; Masson, P.; Foing, B.; Hoffmann, H.; Kreslavsky, M.; Werner, S.; Milkovich, S.; Van Gasselt, S.; Co-Investigator Team, The Hrsc; et al. (2005). "Tropical to mid-latitude snow and ice accumulation, flow and glaciation on Mars". Nature. 434 (7031): 346–50. Bibcode:2005Natur.434..346H. doi:10.1038/nature03359. PMID 15772652. 
  24. ^ Plaut, J.; et al. (2008). "Radar Evidence for Ice in Lobate Debris Aprons in the Mid-Northern Latitudes of Mars". Lunar and Planetary Science. XXXIX: 2290. 
  25. ^ Holt, J.; et al. (2008). "Radar Sounding Evidence for Ice within Lobate Debris Aprons near Hellas Basin, Mid-Southern Latitudes of Mars". Lunar and Planetary Science. XXXIX: 2441. 
  26. ^ Plaut Jeffrey J.; Safaeinili, Ali; Holt, John W.; Phillips, Roger J.; Head, James W.; Seu, Roberto; Putzig, Nathaniel E.; Frigeri, Alessandro; et al. (28 January 2009). "Radar evidence for ice in lobate debris aprons in the mid-northern latitudes of Mars" (PDF). Geophysical Research Letters. 36 (2): L02203. Bibcode:2009GeoRL..3602203P. doi:10.1029/2008GL036379. 
  27. ^ "Mars' climate in flux: Mid-latitude glaciers | Mars Today - Your Daily Source of Mars News". Mars Today. Retrieved 2012-01-16. 
  28. ^ "Glaciers Reveal Martian Climate Has Been Recently Active". Providence, RI: Brown University. April 23, 2008. Retrieved 2015-02-20. 
  29. ^ "The Surface of Mars" Series: Cambridge Planetary Science (No. 6) ISBN 978-0-511-26688-1 Michael H. Carr, United States Geological Survey, Menlo Park
  30. ^ Hugh H. Kieffer (1992). Mars. University of Arizona Press. ISBN 978-0-8165-1257-7. Retrieved March 7, 2011. 
  31. ^ Levy, J. et al. 2009. Concentric crater fill in Utopia Planitia: History and interaction between glacial "brain terrain" and periglacial processes. Icarus: 202. 462-476.
  32. ^ Levy, J., J. Head, D. Marchant. 2010. Concentric Crater fill in the northern mid-latitudes of Mars: Formation process and relationships to similar landforms of glacial origin. Icarus 2009, 390-404.
  33. ^ Levy, J., J. Head, J. Dickson, C. Fassett, G. Morgan, S. Schon. 2010. Identification of gully debris flow deposits in Protonilus Mensae, Mars: Characterization of a water-bearing, energetic gully-forming process. Earth Planet. Sci. Lett. 294, 368–377.
  34. ^ http://hirise.lpl.arizona.edu/ESP_032569_2225
  35. ^ Garvin, J., S. Sakimoto, J. Frawley. 2003. Craters on Mars: Geometric properties from gridded MOLA topography. In: Sixth International Conference on Mars. July 20–25, 2003, Pasadena, California. Abstract 3277.
  36. ^ Garvin, J. et al. 2002. Global geometric properties of martian impact craters. Lunar Planet. Sci: 33. Abstract # 1255.
  37. ^ http://photojournal.jpl.nasa.gov/catalog/PIA09662
  38. ^ Kreslavsky, M. and J. Head. 2006. Modification of impact craters in the northern planes of Mars: Implications for the Amazonian climate history. Meteorit. Planet. Sci.: 41. 1633-1646
  39. ^ Madeleine, J. et al. 2007. Exploring the northern mid-latitude glaciation with a general circulation model. In: Seventh International Conference on Mars. Abstract 3096.
  40. ^ http://hirise.lpl.arizona.edu/PSP_002917_2175
  41. ^ Fastook, J., J. Head. 2014. Concentric crater fill: Rates of glacial accumulation, infilling and deglaciation in the Amazonian and Noachian of Mars. 45th Lunar and Planetary Science Conference (2014) 1227.pdf
  42. ^ "Unraveling the Chaos of Aram | Mars Odyssey Mission THEMIS". Themis.asu.edu. Retrieved 2012-01-16. 
  43. ^ https://web.archive.org/web/20100120223952/http://themis.asu.edu/features/hydraotes. Archived from the original on January 20, 2010. Retrieved January 19, 2012.  Missing or empty |title= (help)
  44. ^ Carr, M. 2001.
  45. ^ Morgenstern, A., et al. 2007
  46. ^ a b Baker, D., J. Head. 2015. Extensive Middle Amazonian mantling of debris aprons and plains in Deuteronilus Mensae, Mars: Implication for the record of mid-latitude glaciation. Icarus: 260, 269-288.
  47. ^ Mangold, N. 2003. Geomorphic analysis of lobate debris aprons on Mars at Mars Orbiter Camera scale: Evidence for ice sublimation initiated by fractures. J. Geophys. Res. 108, 8021.
  48. ^ Levy, J. et al. 2009. Concentric
  49. ^ name=Press>Bright Chunks at Phoenix Lander's Mars Site Must Have Been Ice – Official NASA press release (19.06.2008)
  50. ^ a b http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080619.html
  51. ^ Byrne, S. et al. 2009. Distribution of Mid-Latitude Ground Ice on Mars from New Impact Craters: 329.1674-1676
  52. ^ Head, J. et al. 2003.
  53. ^ Madeleine, et al. 2014.
  54. ^ Schon, et al. 2009. A recent ice age on Mars: Evidence for climate oscillations from regional layering in mid-latitude mantling deposits. Geophys. Res. Lett. 36, L15202.
  55. ^ a b Hecht, M. 2002. Metastability of water on Mars. Icarus 156, 373–386
  56. ^ a b Mustard, J., et al. 2001. Evidence for recent climate change on Mars from the identification of youthful near-surface ground ice. Nature 412 (6845), 411–414.
  57. ^ Pollack, J., D. Colburn, F. Flaser, R. Kahn, C. Carson, and D. Pidek. 1979. Properties and effects of dust suspended in the martian atmosphere. J. Geophys. Res. 84, 2929-2945.
  58. ^ Boynton, W., and 24 colleagues. 2002. Distribution of hydrogen in the nearsurface of Mars: Evidence for sub-surface ice deposits. Science 297, 81–85
  59. ^ Kuzmin, R, et al. 2004. Regions of potential existence of free water (ice) in the near-surface martian ground: Results from the Mars Odyssey High-Energy Neutron Detector (HEND). Solar System Research 38 (1), 1–11.
  60. ^ Mitrofanov, I. et al. 2007a. Burial depth of water ice in Mars permafrost subsurface. In: LPSC 38, Abstract #3108. Houston, TX.
  61. ^ Mitrofanov, I., and 11 colleagues. 2007b. Water ice permafrost on Mars: Layering structure and subsurface distribution according to HEND/Odyssey and MOLA/ MGS data. Geophys. Res. Lett. 34 (18). doi:10.1029/2007GL030030.
  62. ^ Mangold, N., et al. 2004. Spatial relationships between patterned ground and ground ice detected by the neutron spectrometer on Mars. J. Geophys. Res. 109 (E8). doi:10.1029/ 2004JE002235.
  63. ^ Feldman, W., and 12 colleagues. 2002. Global distribution of neutrons from Mars: Results from Mars Odyssey. Science 297, 75–78.
  64. ^ Feldman, W., et al. 2008. North to south asymmetries in the water-equivalent hydrogen distribution at high latitudes on Mars. J. Geophys. Res. 113. doi:10.1029/2007JE003020.
  65. ^ Bright Chunks at Phoenix Lander's Mars Site Must Have Been Ice – Official NASA press release (19.06.2008)
  66. ^ "Confirmation of Water on Mars". Nasa.gov. 2008-06-20. Retrieved 2012-07-13. 
  67. ^ Mutch, T.A., and 24 colleagues, 1976. The surface of Mars: The view from the Viking2 lander. Science 194 (4271), 1277–1283.
  68. ^ Mutch, T., et al. 1977. The geology of the Viking Lander 2 site. J. Geophys. Res. 82, 4452–4467.
  69. ^ Levy, J., et al. 2009. Thermal contraction crack polygons on Mars: Classification, distribution, and climate implications from HiRISE observations. J. Geophys. Res. 114. doi:10.1029/2008JE003273.
  70. ^ Washburn, A. 1973. Periglacial Processes and Environments. St. Martin’s Press, New York, pp. 1–2, 100–147.
  71. ^ Mellon, M. 1997. Small-scale polygonal features on Mars: Seasonal thermal contraction cracks in permafrost. J. Geophys. Res. 102, 25,617-625,628.
  72. ^ Mangold, N. 2005. High latitude patterned grounds on Mars: Classification, distribution and climatic control. Icarus 174, 336–359.
  73. ^ Marchant, D., J. Head. 2007. Antarctic dry valleys: Microclimate zonation, variable geomorphic processes, and implications for assessing climate change on Mars. Icarus 192, 187–222
  74. ^ http://www.diss.fu-berlin.de/diss/servlets/MCRFileNodeServlet/FUDISS_derivate_000000003198/16_ColdClimateLandforms-13-utopia.pdf?hosts=
  75. ^ Kostama, V.-P., M. Kreslavsky, Head, J. 2006. Recent high-latitude icy mantle in the northern plains of Mars: Characteristics and ages of emplacement. Geophys. Res. Lett. 33 (L11201). doi:10.1029/2006GL025946. K>
  76. ^ Malin, M., Edgett, K. 2001. Mars Global Surveyor Mars Orbiter Camera: Interplanetary cruise through primary mission. J. Geophys. Res. 106 (E10), 23429–23540.
  77. ^ Milliken, R., et al. 2003. Viscous flow features on the surface of Mars: Observations from high-resolution Mars Orbiter Camera (MOC) images. J. Geophys. Res. 108 (E6). doi:10.1029/2002JE002005.
  78. ^ Mangold, N. 2005. High latitude patterned grounds on Mars: Classification, distribution and climatic control. Icarus 174, 336–359.
  79. ^ Kreslavsky, M., Head, J. 2000. Kilometer-scale roughness on Mars: Results from MOLA data analysis. J. Geophys. Res. 105 (E11), 26695–26712.
  80. ^ Seibert, N., J. Kargel. 2001. Small-scale martian polygonal terrain: Implications for liquid surface water. Geophys. Res. Lett. 28 (5), 899–902. S
  81. ^ Kreslavsky, M.A., Head, J.W., 2002. High-latitude Recent Surface Mantle on Mars: New Results from MOLA and MOC. European Geophysical Society XXVII, Nice.
  82. ^ Head, J.W., Mustard, J.F., Kreslavsky, M.A., Milliken, R.E., Marchant, D.R., 2003. Recent ice ages on Mars. Nature 426 (6968), 797–802.
  83. ^ Lefort, A.; Russell, P. S.; Thomas, N.; McEwen, A. S.; Dundas, C. M.; Kirk, R. L. (2009). "Observations of periglacial landforms in Utopia Planitia with the High Resolution Imaging Science Experiment (HiRISE)". Journal of Geophysical Research. 114 (E4). Bibcode:2009JGRE..11404005L. doi:10.1029/2008JE003264. 
  84. ^ Morgenstern, A; Hauber, E; Reiss, D; van Gasselt, S; Grosse, G; Schirrmeister, L (2007). "Deposition and degradation of a volatile-rich layer in Utopia Planitia, and implications for climate history on Mars" (PDF). Journal of Geophysical Research: Planets. 112 (E6): E06010. Bibcode:2007JGRE..11206010M. doi:10.1029/2006JE002869. 
  85. ^ Lefort, A.; Russell, P.S.; Thomas, N. (2010). "Scalloped terrains in the Peneus and Amphitrites Paterae region of Mars as observed by HiRISE". Icarus. 205 (1): 259. Bibcode:2010Icar..205..259L. doi:10.1016/j.icarus.2009.06.005. 
  86. ^ Zanetti, M.; Hiesinger, H.; Reiss, D.; Hauber, E.; Neukum, G. (2009). "Scalloped Depression Development on Malea Planum and the Southern Wall of the Hellas Basin, Mars" (PDF). Lunar and Planetary Science. 40. p. 2178, abstract 2178. Bibcode:2009LPI....40.2178Z. 
  87. ^ http://hiroc.lpl.arizona.edu/images/PSP?diafotizo.php?ID=PSP_002296_1215
  88. ^ Baker, V. 1982. The Channels of Mars. Univ. of Tex. Press, Austin, TX
  89. ^ http://hirise.lpl.eduPSP_008508_1870
  90. ^ Bleacher, J. and S. Sakimoto. Pedestal Craters, A Tool For Interpreting Geological Histories and Estimating Erosion Rates. LPSC
  91. ^ http://themis.asu.edu/feature_utopiacraters
  92. ^ McCauley, J. F. (1973). "Mariner 9 evidence for wind erosion in the equatorial and mid-latitude regions of Mars". Journal of Geophysical Research. 78 (20): 4123–4137. Bibcode:1973JGR....78.4123M. doi:10.1029/JB078i020p04123. 
  93. ^ Levy, J. et al. 2008. Origin and arrangement of boulders on the martian northern plains: Assessment of emplacement and modification environments> In 39th Lunar and Planetary Science Conference, Abstract #1172. League City, TX
  94. ^ Levy, J., J. Head, D. Marchant. 2009. Concentric crater fill in Utopia Planitia: History and interaction between glacial "brain terrain" and periglacial mantle processes. Icarus 202, 462–476.
  95. ^ S. Fagents1,A., P. Lanagan, R. Greeley. 2002. Rootless cones on Mars: a consequence of lava-ground ice interaction. Geological Society, Londo. Special Publications: 202, 295-317.
  96. ^ http://www.psrd.hawaii.edu/June01/lavaIceMars.html
  97. ^ Jaeger, W., L. Keszthelyi, A. McEwen, C. Dundas, P. Russell, and the HiRISE team. 2007. EARLY HiRISE OBSERVATIONS OF RING/MOUND LANDFORMS IN ATHABASCA VALLES, MARS. Lunar and Planetary Science XXXVIII 1955.pdf.
  98. ^ Head, J., J. Mustard. 2006. Breccia dikes and crater-related faults in impact craters on Mars: Erosion and exposure on the floor of a crater 75 km in diameter at the dichotomy boundary, Meteorit. Planet Science: 41, 1675-1690.
  99. ^ Mangold et al. 2007. Mineralogy of the Nili Fossae region with OMEGA/Mars Express data: 2. Aqueous alteration of the crust. J. Geophys. Res., 112, doi:10.1029/2006JE002835.
  100. ^ Mustard et al., 2007. Mineralogy of the Nili Fossae region with OMEGA/Mars Express data: 1. Ancient impact melt in the Isidis Basin and implications for the transition from the Noachian to Hesperian, J. Geophys. Res., 112.
  101. ^ Mustard et al., 2009. Composition, Morphology, and Stratigraphy of Noachian Crust around the Isidis Basin, J. Geophys. Res., 114, doi:10.1029/2009JE003349.

Recommended reading[edit]

  • Lorenz, R. 2014. The Dune Whisperers. The Planetary Report: 34, 1, 8-14
  • Lorenz, R., J. Zimbelman. 2014. Dune Worlds: How Windblown Sand Shapes Planetary Landscapes. Springer Praxis Books / Geophysical Sciences.
  • Grotzinger, J. and R. Milliken (eds.). 2012. Sedimentary Geology of Mars. SEPM.

External links[edit]