Mars Reconnaissance Orbiter (MRO)
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ESP_017528_1830_RED_abrowse.jpgGully-like Landforms in Aram Chaos (Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)112 visiteThis observation shows erosional features on light-toned rocks in Aram Chaos, a crater near the Equator of Mars that has been nearly filled with sedimentary rocks.
In enhanced color, the sediments are very distinctive. The rocks show a sharp change in color partway down the slope, indicating a change in the properties of the rock, probably to a different composition.
The erosional features have Alcoves with Aprons downslope, and in some cases have hints of channels, potentially due to abrasion by falling debris.
These morphologies bear some resemblance to Gullies commonly found in the Mid-Latitudes, which are often thought to have formed due to erosion by liquid water from melting snow.
Near the Equator, however, snowmelt in Mars' recent climate is less likely.MareKromium
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ESP_017546_1965_RED_abrowse-PCF-LXTT.jpgFeatures of Amazonis Planitia (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)189 visiteMars Local Time: 15:10 (early afternoon)
Coord. (centered): 16,1° North Lat. and 205,7° East Long.
Spacecraft altitude: 283,3 Km (such as about 177,0 miles)
Original image scale range: 56,7 cm/pixel (with 2 x 2 binning) so objects ~ 1 mt and 70 cm across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 2,3°
Phase Angle: 47,3°
Solar Incidence Angle: 45° (meaning that the Sun is about 45° above the Local Horizon)
Solar Longitude: 81,9° (Northern Spring)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
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ESP_017581_1765_RED_abrowse.jpgExposed Light Material in Upland Region in Aureum Chaos (Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)128 visiteThe Plateau visible in this image is located within Aureum Chaos. Chaotic Terrains on Mars are blocky, fractured regions of flat-topped hills, plateaus, plains and depressions thought to have formed by the collapse of the heavily cratered uplands.
Large Outflow Channels appear to emerge from Aureum Chaos and other Chaotic Terrains leading researchers to posit that these large collapse regions were formed by the catastrophic release of ground water. Aureum Chaos is located just to the North-East of Valles Marineris adjacent to Margaritifer Terra, and it has a diameter of approximately 368 kilometers.
The steep-sided Plateau in this image has a sharp, undulating surface possibly etched out and eroded by persistent winds. These same winds may well have transported the resulting sediment to the surrounding plains helping to form the Dunes below. The Plateau slopes are steep and consist of a series of parallel bright, more resistant cliff forming layers and darker, less resistant slope material. A good way to see the differences in color between the plateau's bright layered deposits and the surrounding area is to look at some of the blocks that have fallen off the cliff onto the the dark sands below.
By studying areas of Mars such as this one, researchers hope to understand how the chaos regions formed and how their formation related to the release of ground water to form the outflow channels, if indeed the two are connected in this way.
Written by: Shawn Hart and Ginny GulickMareKromium
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ESP_017693_1795_RED_abrowse.jpgThermal Anomaly in Aeolis and Zephyria Regions (Saturated Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)129 visiteThis image is taken of an interesting Linear Surface Feature in the Aeolis and Zephyria regions. Using the daytime IR imaging data from the THEMIS instrument, this feature has a higher daytime temperature than its surroundings while also being relatively dark.
When viewed at full HiRISE resolution, this area contains Sand Ripples with some consolidated, Bedrock-like material poking through. These Bedrock Outcrops are more pronounced along the southern portion of the image and are most apparent in the region of the Thermal Anomaly. The Outcrops trend generally East-West and appear sculpted by aeolian erosion.
In the area of the Anomaly, the sand between these Outcrops has a darker tone and gradually blends with the lighter material to either side. This darker sand may be the reason why the material has a "hot" signature compared to its surroundings, because dark materials absorb sunlight more efficiently.
Features similar to the one in this image help researchers to characterize such features and to understand whether such exposures may indicate possible Hydrothermal Fissures, or perhaps be just an exposure of a darker underlying material.
Written by: Shawn Hart and Ginny GulickMareKromium
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ESP_017736_1550_RED-EB-PCF-LXTT1.jpg15-Km Diameter Unnamed Impact Crater (Absolute Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visitenessun commentoMareKromium
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ESP_017736_1550_RED-EB-PCF-LXTT2.jpgRolling Rocks (Absolute Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)55 visitenessun commentoMareKromium
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ESP_017888_1950_RED_abrowse.jpgOlympus' Lava Flows (Extremely Enhanced Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)54 visiteThe flanks of Olympus Mons are covered with Lava Flows (one on top of the other) Most of these Flows are relatively narrow, with a channel running down the middle. They appear similar to the Lava Flows found on Mt. Etna in Sicily (Italy).
However, in this image, we see these typical Flows partially covered by another, more recent one. This last one also shows a Central Channel, and it is about 10 times wider than the more typical Lava Flows. At the center of the HiRISE image the Channel disappears.
This is probably because the Channel was blocked here and Lava spilled out of it and covered a broad, fan-shaped, area. The eruption that produced this unusual flow was probably more vigorous and perhaps lasted longer than the more common ones.MareKromium
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ESP_017897_2045_RED_abrowse-PCF-LXTT.jpgMawrth Vallis (Absolute Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)55 visitenessun commentoMareKromium
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ESP_017900_2185_RED_abrowse.jpgUnnamed Impact Crater cut by Faults (Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visiteThis image reveals an interesting coincidence of two important Planetary Processes: Cratering by Impacts and Tectonism.
Here we have an Impact Crater (the large round feature, approx. 6,2 Km, or 3,9 miles, across) that intersects a series of Faults (the linear features). The Faults are seen to cut the circular Rim of the Impact Crater. Also, the impact did not destroy the adjacent faults. These observations tell us that the Fault was active after the impact occurred.
In addition, by measuring the distance of offset of the different pieces of the Crater Rim separated by the Fault Line (assuming that when the Crater formed, the Rim was continuous around its circumference), the amount of movement along the Fault can be estimated, laterally and vertically. Faults like these cause Troughs to form, called "Graben", of which the heavily shadowed one is a good example. The center (shadowed) section has been dropped downwards relative to the surrounding Terrain, forming the Trough.
It is also clear that parts of the Crater Rim are lower than others where the Graben intersects the Crater. The sides of the Graben (the Faults forming the Walls of the Trough) are sloped, so that the dropped-down part of the Crater Rim has also moved horizontally away from its higher part. The combined down-dropping and moving apart indicates that the land here is being stretched and pulled apart, called "extension". By measuring the amount of offset on all the Faults, we can estimate how much extension has occurred in this part of the Planet.
This location is especially helpful because, as mentioned above, we have a good knowledge of the “before-faulting” configuration of the land, in which the Crater Rim was continuous. Finally, it is interesting that there is no sign of the Fault on the Floor of the Crater – its Floor has not been faulted and no part is down-dropped and stretched apart as the Rim has been. This indicates that some infilling of the Crater (perhaps by Lava or Airborne Sediment) has likely occurred since the Fault was active, burying the trace of the Fault and representing a third stage of geologic history in this area.MareKromium
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ESP_017950_2205_RED_abrowse.jpgMore "Mud-Volcanoes" (?) in Acidalia Planitia (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)105 visiteMareKromium
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ESP_018011_2565_RED_abrowse.jpgBetween Abalos and Olympia Undae... (Absolute Natural Colors; credits: Dr Paolo C. Fienga - Lunexit Team)54 visiteThis HiRISE image shows some large Sand Dunes near the North Pole of Mars. The picture was taken in summertime, with only small patches of ice remaining on the Surface: this show up as bright, somewhat blue, spots on slopes that provide some shading from the Sun.
Geologists would classify these Dunes as "sand-starved" because the ground between the Dunes has almost no sand; in addition, this ground shows a pattern of cracks that is typical of icy permafrost undergoing through seasonal expansion and contraction.
It is also possible that some Subsurface Ice exists inside the Dunes themselves; if so, the Dunes are not currently moving, and the ice is acting as a "stabilizer".
This idea is supported by the observation that there are small Landslide Gullies being cut into the Dunes, something not seen if the Dunes are rejuvenated as they move in the wind. However, to test this idea this area has been repeatedly imaged by multiple cameras on different spacecrafts.
With meticulous care it will be eventually possible to determine just how much the Dunes have moved or changed over the past years.MareKromium
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ESP_018023_2145_RED-MF-LXTT.jpgMartian "Oklo" (an Image-Mosaic in Natural Colors; credits for the additional process. and color.: Drr Marco Faccin and Paolo C. Fienga - Lunexit Team)104 visitenessun commentoMareKromium
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