| Piú votate - Mars Reconnaissance Orbiter (MRO) |
PSP_001420_2045_RED_browse-01~0.jpgSmall Channel in Tartarus Colles (EDM - Natural Colors; credits: Lunexit)66 visiteThe Channel between the Knobs has a variable depth as seen by the varying shadow lengths. The origin of the Channel is unknown, but it is probably NOT a Fluvial Channel because there are no obvious source or Deposit Regions; the Channel, therefore, is probably a Collapse Feature.
One portion of it, (see this EDM, approx. 375 meters across), contains a Bridge, and is probably a remnant of the original surface.
A depression that extends from the Channel Northwards — but which is not as deep as the majority of the Channel — might be in the process of collapsing and enlarging the Channel. MareKromium
(1 voti)
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PSP_001422_1750_RED_abrowse.jpgLayers in Gale Crater Central Mound (Natural Colors; credits: Lunexit)54 visiteThis image shows a portion of the Central Mound in the Gale Crater (Central Mound that is of interest to scientists because of the light-toned Layered Deposits that can be found inside it).
The Layered Deposits could have formed in a water environment if, for instance, a lake - once - filled the Crater. Alternatively, particles suspended in the Atmosphere, such as Dust or Volcanic Ashes, could have built up the Layers over time.
By using HiRISE images to see details in the Layers, such as how their thicknesses vary horizontally and vertically, scientists can narrow down the potential origins.
The paucity of Impact Craters on the Layered Deposits indicates that either the Deposits are very young, or more likely that they are being eroded up to the point where such (alleged) Impact Craters were erased.
Wind Erosion modified the Layers after they formed, creating both sharp corners and rounded depressions along the Surface.
A few meter-size Boulders are visible at the base of some steep Cliffs, but the really poor amount of visible Boulders elsewhere suggests that most of the erosion occurred (and it is still occurring) because of eolic processes (such as wind action) rather than downslope movement of material.MareKromium
(1 voti)
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ESP_014298_1375_RED_abrowse.jpgNereidum Montes (Natural Colors; credits: Lunexit)57 visitenessun commentoMareKromium
(1 voti)
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ESP_011873_1675_RED_abrowse.jpgLayering and Faulting in Candor Chasma (Natural Colors; credits: Lunar Explorer Italia)54 visitenessun commentoMareKromium
(1 voti)
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PSP_010630_2115_RED_abrowse-01.jpgCraters and possible "Pingo" in Mamers Vallis (edm - Natural Colors; credits: Lunar Explorer Italia)86 visite"At first this resembles a cinder cone volcano on Earth. However, when magnified, it reveals a feature [found in Arctic regions] on Earth called "Pingo". These are caused by ice protruding through the soil creating a positive-relief geologic feature. If you examine the smaller craters in the surrounding terrain you'll see a checkerboard pattern in each one. These closely resemble melted Pingos on Earth, again suggesting an area of Mars that was once rich with water."
While the student's suggestion that the mound-like structure is a Pingo is reasonable, there is yet no scientific consensus for the origin of these interesting structures.
Nota Lunexit: con tutto il rispetto per le brillanti intuizioni dei ragazzini "sponsorizzati" dalla NASA, l'idea del "Pingo" non stà - davvero - nè in cielo, nè in Terra. Eppure, come leggete, anche a queste boutades (perchè provengono da fanciulli - probabilmente - "quotati" a tutti i livelli), viene dato spazio. Poi però, se chiedi ai Signori di Pasadena o della University of Arizona, ad esempio, cosa potrebbe essere la Silver Sphere (o altri rilievi anomali simili, a parer nostro - e NON SOLO nostro - MOLTO più intriganti dello "pseudo Pingo")...Ecco che cala il silenzio più totale.
Che tristezza...MareKromium
(1 voti)
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ESP_012252_1245_RED_abrowse.jpgDust Devils Tracks (Natural Colors; credits: Lunar Explorer Italia)73 visiteThis image is located in a crater in the Hellespontus region that displays dunes and dust devil tracks.
The larger barchan-like dunes are surrounded by linear ripples and dark coarse material. The dunes are composed of basaltic sands that have accumulated in the troughs of the dunes. The dunes themselves run in a northeast to southwest direction. The steep west facing slip face indicates that the dune is controlled by a southeasterly direction and that the winds here tend to blow from left to right.
Both the sandy and rough textured surfaces are crisscrossed by the tracks of dust devils. These tracks form when dust devils abrade the surface exposing the underlying darker surface. The tracks appear to be clustered since dust devils frequently form in areas that have been previously scoured. The lighter tracks are older tracks that are fading or have been overprinted by other dust devils.
It is possible that the dunes are stable as many of the dust devils appear to be going to the southeast direction (based on scallop patterns- dust devil leaves behind dark circular patterns and erase the frost as it moves forward by local winds). This is an indication of change of wind especially since the dune field is in a crater.
MareKromium
(1 voti)
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ESP_011633_1195_RED_abrowse.jpgDunes (Natural Colors; credits: Lunar Explorer Italia)57 visitenessun commentoMareKromium
(1 voti)
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PSP_010437_1655_RED_abrowse.jpgSample of Southern Surface (Natural Colors; credits: Lunar Explorer Italia)84 visiteMars Local Time: 15:42 (middle afternoon)
Coord. (centered): 14,5° South Lat. and 253,6° East Long.
Spacecraft altitude: 251,9 Km (such as about 157,5 miles)
Original image scale range: 25,2 cm/pixel (with 1 x 1 binning) so objects ~ 76 cm across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 0,2°
Phase Angle: 62,3°
Solar Incidence Angle: 62° (meaning that the Sun is about 28° above the Local Horizon)
Solar Longitude: 143,3° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
(1 voti)
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PSP_010447_1525_RED_abrowse.jpgKashira Crater (Natural Colors; credits: Lunar Explorer Italia)68 visiteMars Local Time: 15:44 (middle afternoon)
Coord. (centered): 27,0° South Lat. and 342,2° East Long.
Spacecraft altitude: 257,4 Km (such as about 160,8 miles)
Original image scale range: 51,5 cm/pixel (with 1 x 1 binning) so objects ~ 1,54 mt across are resolved
Map projected scale: 50 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 0,3°
Phase Angle: 68,8°
Solar Incidence Angle:69° (meaning that the Sun is about 21° above the Local Horizon)
Solar Longitude: 143,7° (Northern Summer)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
(1 voti)
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ESP_011765_1780_RED_abrowse-01.jpgRipples in Meridiani Planum (edm - Natural Colors; credits: Lunar Explorer Italia)53 visitenessun commentoMareKromium
(1 voti)
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ESP_011635_1510_RED_abrowse.jpgRitchey Crater's Central Uplift (Natural Colors; credits: Lunar Explorer Italia)72 visiteThe Natural Color image of this observation includes some interesting features in and near the central uplift of Ritchey Crater.
At the top is an ancient streambed, above center are very bright rocks and minerals can be seen in the Central Uplift. Large impact craters are unstable when they are formed, because their Walls are so steep.
Gravity causes the Walls to collapse toward the center of the Crater, colliding to form an Uplift or Peak. This process of Central Uplift formation can bring rocks from deep in the Crater Walls up to the surface. The angular bright blocks near the center of this image show that this process breaks the wall rocks into fragments as the Central Uplift is formed.
Mars Local Time: 16:00 (middle afternoon)
Coord. (centered): 28,5° South Lat. and 309,1° East Long.
Spacecraft altitude: 264,8 Km (such as about 165,5 miles)
Original image scale range: 26,5 cm/pixel (with 1 x 1 binning) so objects ~79 cm across are resolved
Map projected scale: 25 cm/pixel
Map projection: EQUIRECTANGULAR
Emission Angle: 15,1°
Phase Angle: 46,9°
Solar Incidence Angle: 61° (meaning that the Sun is about 29° above the Local Horizon)
Solar Longitude: 194,0° (Northern Autumn)
Credits: NASA/JPL/University of Arizona
Additional process. and coloring: Lunar Explorer ItaliaMareKromium
(1 voti)
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PSP_009905_2650_RED.jpgNorth Polar Layered Deposits (NPLD) and Dunes in Chasma Boreale (natural colors; credits: Lunexit)60 visiteThis image shows a steep, layered slope and flatter, dune-covered plains in Mars’ North Polar Region. The layers are composed of varying contents of water ice and dust.
On Earth, icy layers like these in Greenland and Antarctica are important because they contain a record of past climate conditions. By looking at the detailed sequence of Polar Layers on Mars, scientists hope to be able to discover the types of variations that Mars’ climate may have experienced.
The lowest section in the stack of light layers is noticeably darker because of the presence of dark, sandy material. Erosion of this dark material is thought to provide the sand making up the large dunes on the plains.
Several exceptionally well-developed barchan (crescent-shaped) dune forms up to approximately 50 meters (160 feet) across are present in the center of the image.MareKromium
(1 voti)
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