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Mars Reconnaissance Orbiter (MRO)
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SubsurfaceIce-PIA12217.jpgSubsurface Ice (Natural Colors; credits: Lunexit)54 visiteThe High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter took these images of a fresh, 6-meter-wide (20-foot-wide) crater on Mars on Oct. 18, 2008, (left) and on Jan. 14, 2009. Each image is about 35 meters (115 feet) across.
This crater's depth is estimated to be 1,33 meters (4,4 feet).
Images (not shown here) taken by the Thermal Emission Imaging System camera on NASA's Mars Odyssey orbiter and by the Context Camera on the Mars Reconnaissance Orbiter show that the impact that excavated this crater occurred sometime between Dec. 22, 2008 and July 5, 2008.
The impact exposed water ice from below the Surface. It is the bright material visible in this pair of images. The change in appearance from the earlier image to the later one resulted from some of the ice sublimating away during the Martian Northern-Hemisphere Summer, leaving behind dust that had been intermixed with the ice. The thickening layer of dust on top obscured the remaining ice.
This crater is at 43,28° North Latitude and 164,22° East Longitude.MareKromium
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SubsurfaceIce-PIA12218.jpgSubsurface Ice (Natural Colors; credits: Lunexit)54 visiteThis 6-meter-wide (20-foot-wide) Impact Crater located in Mid-Latitude Northern Mars was created by an impact that occurred between Jan. 22, 2008, and Sept. 15, 2008, as bracketed by before-and-after images (not shown here).
The images shown here were taken by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter on Oct. 29, 2008, (left) and on Jan. 4, 2009. Each image is about 35 meters (115 feet) across.
The crater's depth is estimated to be 1,76 meters (5,8 feet).
The impact that dug the Crater excavated water ice from beneath the Surface. It is the bright material visible in this pair of images. A change in appearance from the earlier image to the later one resulted from some of the ice sublimating away during the Northern-Hemisphere Summer, leaving behind dust that had been intermixed with the ice. The thickening layer of dust on top obscured some of the remaining ice.
This crater is at 45,05° North Latitude and 164,71° East Longitude.MareKromium
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SubsurfaceIce-PIA12219.jpgSubsurface Ice (Natural Colors; credits: Lunexit)54 visiteThis 12-meter-wide (39-foot-wide) Impact Crater located in Mid-Latitude Northern Mars was created by an impact that occurred between July 3, 2004, and June 28, 2008, as bracketed by before-and-after images (not shown here).
The images shown here were taken by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter on Nov. 19, 2008, (left) and on Jan. 8, 2009. Each image is about 35 meters (115 feet) across.
The impact that dug the Crater excavated water ice from below the Surface. It is the bright material visible in this pair of images. This Crater is at 46,16° North Latitude and 188,51° East Longitude.MareKromium
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SubsurfaceIce-PIA12220.jpgMaterial excavated by a "Fresh Impact" is identified as Water Ice (Natural Colors; credits: Lunexit)54 visiteThe bright material conspicuous in this image was excavated from below the Surface and deposited nearby by a 2008 impact that dug a crater about 8 meters (26 feet) in diameter.
The extent of the bright patch was large enough for the Compact Reconnaissance Imaging Spectrometer for Mars, an instrument on NASA's Mars Reconnaissance Orbiter, to obtain information confirming the material to be water ice.
This image, covering an area 50 meters (164 feet) across, was taken on Nov. 1, 2008, by the High Resolution Imaging Science Experiment on the same Orbiter. The time frame for the crater-forming impact to have occurred was bracketed by before-and-after images (not shown) taken by the Thermal Emission Imaging System camera aboard NASA's Mars Odyssey Orbiter on Jan. 26, 2008, and by the Context Camera on the Mars Reconnaissance Orbiter on Sept. 18, 2008.
This Crater is at 55,57° North Latitude and 150,62° East Longitude (Vastitas Borealis Region). MareKromium
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Syrtis_Major_Planum-ESP_023089_1960_RED_abrowse-PCF-LXTT.jpgFeatures of Syrtis Major Planum (Absolute Natural Colors; credits for the additional process. and color: Dr Paolo C. Fienga - Lunexit Team)234 visiteMars Local Time: 14:06 (Early Afternoon)
Coord. (centered): 15,7° North Lat. and 74,2° East Long.
Spacecraft altitude: 277,8 Km (such as about 173,6 miles)
Original image scale range: 27,8 cm/pixel (with 1 x 1 binning) so objects ~ 55,6 cm across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 6,3°
Sun-Mars-Spacecraft (or "Phase") Angle: 39,7°
Solar Incidence Angle: 44° (meaning that the Sun is about 46° above the Local Horizon)
Solar Longitude: 320,1° (Northern Winter)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Dr Paolo C. Fienga - Lunar Explorer ItaliaMareKromium
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T-TRA_000827_1875_RED.jpgA long trough in Cerberus Fossae53 visiteThe prominent trough in this image is a segment of the Cerberus Fossae rift system. In geological terminology the trough is known as a graben, or down-dropped region bounded by faults. In this location the graben is about 300 m wide and 90 m deep. Bright, dust-covered, cratered plains surround the graben, and darker sediments blanket much of its floor. Dunes that vary in size and spacing occur within the darker sediments, and their shapes suggest that the wind typically blows from east to west. Light-toned, angular boulders pepper the darker sediments. They have broken away from the rocky walls of the graben and tumbled downhill. Over time this mass wasting has caused the cliffs to retreat, widening the trough. The somewhat lighter patches of cratered terrain on the graben floor were once level with the surrounding plains, but have since been lowered by faulting. Over time they may become obscured or buried by the darker sediments. High-standing ridges - remnants of the former surface - cast jagged shadows on the floor of the graben that reveal the rugged nature of the landscape in this region of Mars.
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T-TRA_000828_1805_RED.jpgYardangs in Medusa Fosse55 visiteThis image covers a portion of an outcrop of the Medusae Fossae Formation, a series of light-toned terrains in the Martian mid-latitudes. The Medusae Fossae has been and remains one of the most enigmatic features on Mars. The unit is characterized by wind-sculpted landforms, most notably eroded ridges known as yardangs. The composition of the Medusae Fossae is not known, but candidates include indurated (hardened) volcanic ash or remnants of dust-ice mixtures that formed in a different Martian climate. This HiRISE image reveals new details of the Medusae Fossae.
Three prominent yardangs are seen, at upper right, lower center right, and partially at lower right. They are aligned with their long axes pointing NW-SE, with tapered ends on the NW, consistent with erosion from a southeasterly wind. One or more hard rocky layers within the yardangs are visible, with the layers commonly segregated into discreet boulders. Isolated rocks are seen on the slopes and at the base of the yardangs, indicating that some formed from breakup of the layers. The rocks may be similar in composition to the softer, non-rocky parts of the yardangs, but simply more indurated. Alternatively, they may be compositionally distinct, challenging current hypotheses for the origin of the Medusae Fossae.
Light-toned ridges at center left have a gross morphology similar to that of barchanoid dunes, formed from wind-blown sand. If these are dunes or ripples, their orientation is consistent with the presumed wind direction that carved the yardangs. However, zooming in to full resolution reveals flat tops, grooves, and smaller, darker ripple forms to the northwest of the ridges. Therefore if these are dunes, they seem indurated.
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T-TRA_000828_2495_RED.jpgNorthern Plains54 visiteA network of shallow surface troughs and fissures coalesce into polygonal patterns that are ubiquitous throughout this image. Polygonal patterned ground of this nature is quite common in permafrost regions of Earth, where seasonal thermal contraction of ice-cemented soil produces a honeycomb network of subsurface cracks. Cracks of this nature can also be produced by desiccation (mud cracks) or lava cooling (columnar joints), though typically on a smaller scale. The diameter of these martian polygons are dominantly 10-20 meters, analogous to terrestrial permafrost. The individual troughs are frequently only a couple of meters or less wide, and easily resolved at HiRISE resolution. Other characteristics, such as small ridges on either side of the troughs and the distribution of rocks in and around each polygon is also readily apparent. Small rocks and occasional larger boulders are also seen scattered throughout the image. Rocks protruding above the surface soil can be seen to cast shadows (solar illumination is from the lower left), which can aid in the determination of the rock's size and height. This image is located near an area under consideration as a landing site for the Mars Scout mission, Phoenix, planned for 2008. Examination of many factors including surface texture (roughness and morphology) and the size distribution of rocks will aid in final landing site selection.
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T-TRA_000830_1440_RED_NigerVallis_01.jpgNiger Vallis56 visiteThis image shows a portion of the floor of Niger Vallis, an ancient Martian outflow channel. Niger Vallis originates on the flanks of the volcano Hadriaca Patera, and empties into the Hellas impact basin. Outflow channels are observed in many regions of the planet, and may have been carved by brief eruptions of liquid water from beneath the surface. Since Niger Vallis formed, impacts have cratered the channel floor, and fine-grained wind-blown debris has been transported across the surface, eroding and burying all but the freshest craters. The curved ridge in the scene may be the remnant of a large crater rim. At the high resolution of this image, a pattern of parallel dunes and ripples can be seen, as well as individual boulders as large as two meters across.
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T-TRA_000833_1800_RED.jpgMeridiani Planum53 visiteThis HiRISE image shows geologic "contacts", or boundaries, between light-toned and dark-toned material in Meridiani Planum, near the equator of Mars. Merdiani Planum is where the Mars Exploration Rover Opportunity is located, although this image covers an area that is more than 600 km to the east of the Opportunity site. The central portion of the image shows very smooth, dark plains that are typical of much of the Meridiani region. These plains are flanked by more rugged lighter-toned materials. The light-toned materials have been eroded to form dramatic pits, buttes and mesas. Based on the lengths of the shadows that they cast, some of the buttes and mesas are up to about 30 meters (~100 feet) tall. The light-toned material shows distinctive layering, suggesting that it may be composed of sedimentary rock. Scattered across the scene, especially in the light-toned materials where they are prominent in low spots and around some of the larger buttes and mesas, are dunes and other similar landforms created by martian winds.
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T-TRA_000834_1835_RED.jpgAram Chaos57 visiteAram Chaos is thought to be a degraded impact crater that was once filled with water and sedimentary units. The term "chaos" refers to the cracks and angled blocks formed perhaps by withdrawl of subsurface material. This sub-image covers only a small portion of Aram Chaos and illustrates the modification of the crater by fracturing, younger impact craters, and wind. A linear fracture cuts through the center of the image while a more sinuous depression filled with bright ripples or dunes is located towards the bottom of the image. Both depressions could have resulted from collapse associated with modification of the impact crater that created Aram Chaos or later disruption when water and sediment covered some of the crater floor. Impact craters of many shapes and sizes can be seen across the image, indicating a relatively older surface that has seen little modification since its formation. The bright ripples or dunes appear to cluster in low-lying topography, such as the sinuous depression and a larger impact crater in the lower right of the image, suggesting that wind has moved fine material along the surface until it becomes trapped in low spots where it collects to form ripples or dunes.
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T-TRA_000836_1740_RED_CandorChasma_01.jpgCandor Chasma55 visiteCandor Chasma is one of several large troughs that make up Valles Marineris, the largest canyon system in the Solar System. Much of Candor Chasma is filled with layered deposits, like those shown in this HiRISE sub-image. Layers only 1-2 meters thick can be resolved by HiRISE and provide details on the processes that emplaced and modified these sediments. The layered deposits could be volcanic, lacustrine, or eolian sediments that filled in some portions of the trough of Valles Marineris. The variations in brightness of the layers could represent compositional differences in the layers or the thickness of overlying debris, such as sand or dust. This area was targeted because minerals rich in sulfur were detected here by the OMEGA instrument on Mars Express. By using HiRISE images to look at specific geologic units that correspond to these locations of sulfate, it may be possible to determine the origin of the sediments, particularly those that contain the sulfates. The paucity of impact craters on the layered deposits suggests either a young age for the sediments or erosion has removed much of the upper layers to reveal a fresher-looking surface. Dark dunes and ripples indicate that wind has been, and still may be, moving debris across the sedimentary deposits.
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