Mars Reconnaissance Orbiter (MRO)
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PSP_010047_1745_RED-01.jpgStar-like shaped Hill in Terra Tyrrhena (edm - possible True Colors; credits: Lunar Explorer Italia)53 visite...Pubblichiamo questo extra-detail magnification (edm) girando a Voi la domanda postaci dal nostro Caro Amico "Cano00": questa striscia di puntini (si direbbero dei mini-segmenti scuri) allineati, che cos'è? E' un intrigantissimo rilievo superficiale, oppure è un image-artifact?
Ed in ogni caso: COMPLIMENTI a Cano00 per l'occhio (straordinario) che ha avuto!...MareKromium
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PSP_010052_1560_RED.jpgFeatures of Eberswalde Crater (natural colors; credits: Lunexit)53 visiteEberswalde Crater is an approx. 65-Km diameter, closed Basin Crater. It contains a delta, which indicates that flowing water was present for an extended period of time in the past.
Parts of the Crater have inverted channels that have higher relief because a more resistant material was deposited in the channel and therefore it was less susceptible to erosion than the surrounding area. The image also shows resistant knobs and mounds as well as a scoured surface.
The CRISM instrument on-board MRO has detected Phyllosilicates (Clays) in some of the bright layers here. On Earth, clays form in the presence of water, so this is more evidence that there was a persistent flow of water in Eberswalde.MareKromium
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PSP_010054_1765_RED.jpgPlain North-West of Tithonium Chasma (possible True Colors; credits: Lunar Explorer Italia)53 visiteMars Local Time: 15:34 (middle afternoon)
Coord. (centered): 3,6° South Lat. and 268,4° East Long.
Spacecraft altitude: 260,2 Km (such as about 162,6 miles)
Original image scale range: 52,1 cm/pixel (with 1 x 1 binning) so objects ~1,56 mt across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 0,3°
Phase Angle: 57,8°
Solar Incidence Angle: 58° (meaning that the Sun is about 32° above the Local Horizon)
Solar Longitude: 128,7° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
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PSP_010057_2040_RED.JPGUnnamed Crater with Ridges and DD Tracks (natural colors; credits: Lunexit)53 visiteThis image shows two features of interest on the floor of a large impact crater. The first is the set of roughly parallel ridges on the crater floor that point towards the crater center north of the image. These may be Inverted Stream Channels, where old streambeds became resistant to erosion due to cementation or simply deposition of large rocks. This is consistent with the slightly wavy, sinuous shape of the ridges, but these examples are not particularly well-preserved.
More recently, this site has become blanketed by dust, settling out after Global Dust Storms. This obscures much of the fine-scale geology, but allows HiRISE to see the effects of a recent process: Dust Devils. These have left the dark stripes across the surface by disturbing the dust cover. Most followed straight paths, but a few loops or turns are visible. Dust Devils may be an important factor in the Martian climate system because they lift dust into the atmosphere, helping to trigger larger Dust Storms.MareKromium
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PSP_010059_1640_RED.jpgOlivine Deposits (possible True Colors; credits: Lunar Explorer Italia)53 visiteMars Local Time: 15:38 (middle afternoon)
Coord. (centered): 16,1° South Lat. and 133,7° East Long.
Spacecraft altitude: 259,9 Km (such as about 162,5 miles)
Original image scale range: 26 cm/pixel (with 1 x 1 binning) so objects ~1,04 mt across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 3,2°
Phase Angle: 61,9°
Solar Incidence Angle: 64° (meaning that the Sun is about 26° above the Local Horizon)
Solar Longitude: 128,9° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
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PSP_010059_2580_RED.jpgSample of North Polar Outlier (possible True Colors; credits: Lunar Explorer Italia)59 visiteMars Local Time: 14:46 (early afternoon)
Coord. (centered): 77,9° North Lat. and 113,6° East Long.
Spacecraft altitude: 318,5 Km (such as about 199,1 miles)
Original image scale range: 31,9 cm/pixel (with 1 x 1 binning) so objects ~96 cm across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 1,7°
Phase Angle: 60,5°
Solar Incidence Angle: 62° (meaning that the Sun is about 28° above the Local Horizon)
Solar Longitude: 128,9° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
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PSP_010063_2135_RED.jpgIsmenius Lacus (possible True Colors; credits: Lunar Explorer Italia)54 visiteMars Local Time: 14:16 (early afternoon)
Coord. (centered): 33,2° North Lat. and 17,4° East Long.
Spacecraft altitude: 296,7 Km (such as about 185,5 miles)
Original image scale range: 29,7 cm/pixel (with 1 x 1 binning) so objects ~59,4 cm across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 6,9°
Phase Angle: 54,4°
Solar Incidence Angle: 47° (meaning that the Sun is about 43° above the Local Horizon)
Solar Longitude: 129,0° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
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PSP_010071_2615_RED.jpgGypsum-rich Dunes in Olympia Undae Region (natural colors; credits: Lunexit)58 visiteIn this enhanced-natural color image are dunes within the largest collection of dunes on Mars, Olympia Undae, near the margin of the North Polar Layered Deposits, Planum Boreum.
This section of Olympia Undae is particularly interesting because the dunes are rich in Gypsum (---> Gesso), a mineral that forms in the presence of water. The material comprising these dunes is thought to have eroded from geologic units near the base of the NPLD, but these units have poor to no gypsum content.
Therefore, water likely affected these dunes after the sand had eroded out from the NPLD. Several ideas have been proposed to explain the formation of Gypsum, including hydrothermal (hot water) activity and melting of water-ice in the NPLD.
While gypsum dunes on Earth (for example, at White Sands, New Mexico) are white (the color of Gypsum), these Martian Dunes are dark due to the presence of basaltic grains that lower the brightness of the dunes.
CRISM, another instrument on MRO, has found that the crests of the dunes are the most Gypsum-rich. So, what is the bright, polygonally-fractured material in the low spaces between the dunes?
Perhaps it is Polar Ice lying beneath, desiccated (dried) gypsum material whose fine grain size makes it difficult for CRISM to detect, or something else altogether.MareKromium
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PSP_010086_2615_RED.jpgInfilled Crater on the North Polar Layered Deposits (natural colors; credits: Lunexit)54 visiteThe Polar Deposits of Mars are among the most geologically active on the Planet today. This image illustrates several processes affecting the Polar Landscape both today and in the recent past.
Frost streaks cross this image from lower left to lower right and are a testament to the power of the wind to redistribute material in this Region. In the center of the image lies an impact crater about 130 meters across (425 feet). Craters on the Polar Deposits are rare because the very active surface processes remove them quickly. This particular crater is likely to have been formed less than 100.000 years ago, which is very recent in geologic terms.
Streaks of material emanating from the crater rim have been created as the ice and dust being transported across the surface by the wind encounters that obstacle.
Although its initial depth was probably about 25 m (80 ft), the crater has been infilled with ice and dust and is now quite shallow. However, in one portion of the crater (upper area), the fill material has been removed, creating a pit adjacent to the crater wall. This pit contains a fresh deposit of ice and may be in the beginning stages of being infilled again. These cycles of infilling and erosion will eventually erase the crater from the landscape.
Scientists can examine many of these craters at different stages in their lifespan, from the very fresh to the almost erased. Using these data we can make estimates of how active this part of the Martian Surface is today.
Of course we need to find these rare craters first! Craters this size are usually about 200 Km (approx. 125 miles) apart in this Region, with the intervening landscape being relatively featureless.MareKromium
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PSP_010090_1255_RED.jpgSpring over Russel Crater (natural colors; credits: Lunexit)57 visiteSpring is already starting to show its influence at the Russell Crater field of sand dunes. Channels down the face of the largest dune show dark spots where the sublimation of the seasonal carbon CO2 Ice Cap has begun.
This active process (where ice evaporates directly to gas) dislodges loose material, leaving dark streaks down steep slopes. The process starts when the Sun peeks above the horizon at the end of Antarctic Night.
Bright streaks may be loose frost cascading down steep slopes.MareKromium
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PSP_010100_2165_RED_abrowse.jpgEjecta Blanket (Natural Colors; credits: Lunar Explorer Italia)54 visiteThis image of a crater in the Utopian Region can be described as what happens when heat produced from an impact comes into contact with Mars’ icy Surface.
Since the Surface Temperature of Mars is well below the freezing point of water, Mars’ soil is a mixture of soil and permafrost. When this impact occurred, a great deal of energy in the form of heat was released onto the Surface, creating a melted feature in the bright icy soil. This melting and then refreezing of the ice (as the impact cooled) caused what is known as a "Periglacial Formation". This is depicted towards the middle of the image where the Ejecta Blanket lays.
This is likely a geologically newer surface since the only impacts disrupting the image are a few small craters that are mostly towards the bottom left-hand side of the full image.
The fact the Ejecta Blanket is still intact and not fully collapsed supports the idea that is it a newer surface feature as it has not been affected by erosional processes.MareKromium
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PSP_010169_2650_RED_abrowse-00.jpgDunes and other Surface Features in Chasma Boreale (ctx frame - possible True Colors; credits: Lunexit)62 visiteThis image shows dark sand dunes in Chasma Boreale. Chasma Boreale is a giant trough that cuts into the North Polar Ice Cap for about 570 Km (approx. 350 miles) forming a broad valley bordered by stacked layers of ice.
A portion of the North Polar Ice Cap is visible at the northern edge of the trough in the left portion of the image.
Many dark toned sand dunes march down the trough under the winds’ direction.
Coord.: 84,9° North Lat. and 331,8° East Long.
Spacecraft altitude: about 319 Km
M.L.T.: 13:35 (early afternoon)
Solar Incidence Angle: 67°MareKromium
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