| Risultati della ricerca nelle immagini - "Promethei" |
Craters-Unnamed_Crater_with_Pedestal-PIA08029.jpgUnnamed Pedestal Crater in Promethei Terra (Original NASA/MGS/MSSS b/w Frame)53 visiteCaption NASA originale:"This MGS-MOC image shows a Pedestal Crater in the Promethei Terra Region. The Ejecta from an impact crater is usually rocky. The rocks in the Ejecta help shield the Terrain beneath the Ejecta from being eroded away by Wind. Thus, over time, some Craters appear to be raised on Pedestals defined by their Ejecta Blankets, because Wind has stripped away tons and tons of surrounding material".
Location near: 65,4° South Lat. and 264,7° West Long.
Image width: ~3 Km (~1,9 mi)
Illumination from: upper left
Season: Southern Autumn
Nota: un altro (relativamente) famoso cratere con (o su) piedistallo si trova su Venere ed è conosciuto con il nome di Cratere Adivar.
|
|
ESP_020319_1470_RED_abrowse-PCF-LXTT.jpgIce-rich Lobate Debris-Aprons in Terra Promethei (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)153 visiteThis image shows a portion of a Lobate "Debris-Apron! along the bottom of a Hill in the Promethei Terra Region of Mars. This Region contains many such Mesas surrounded by Lobate Debris-Aprons that are thought to be ice-rich.
These Aprons have been interpreted as a variety of possible features including Rock Glaciers, ice-rich Mass Movements, or Debris-covered Glacial Flows. Recent radar data have shown them to be composed of nearly 100% pure ice.
Parallel Grooves and Ridges indicate the direction of flow.
Both the Debris-Apron and the Plains beyond it are blanketed with an ice-rich Mantle that is common throughout the Martian Mid-Latitudes. The Mantle Deposits are pitted and grooved perhaps due to the sublimation of ice. This Mantle is thought to have been deposited as snow around 10 million years ago during a period of high obliquity, when the Planet's Axis was more tilted and environmental conditions could have been more conducive to snowfall in these Regions.
Several small Impact Craters are visible on the Plains that appear to have been filled with Mantling Deposits that have subsequently been partially removed. These Craters give us clues to the erosional history of the Deposit.MareKromium
|
|
ESP_021915_1005-PCF-LXTT-0.jpgAeolian Features in Terra Promethei (Enhanced Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)182 visitenessun commentoMareKromium
|
|
ESP_021915_1005-PCF-LXTT-1.jpgPromethei Planum (CTX Frame n.1 - Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)210 visiteAcquisition Date: March, 31st, 2011
Mars Local Time (M.L.T.): 15:55 (Middle Afternoon)
Latitude (centered): 79,5° South
Longitude (East): 109,4°
Range to target site: 249,2 Km
Original image Scale Range: 49,9 cm/pixel (with 2 x 2 binning) so objects ~150 cm across are resolved
Map Projected Scale: 50 cm/pixel
Map projection: POLAR STEREOGRAPHIC
Emission Angle: 3,5°
Phase Angle: 57,4°
Solar Incidence Angle (S.I.A.): 60°, with the Sun about 30° above the Local Horizon
Solar Longitude: 264,8° - Northern AutumnMareKromium
|
|
ESP_021915_1005-PCF-LXTT-2.jpgPromethei Planum (CTX Frame n.2 - Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)205 visiteAcquisition Date: March, 31st, 2011
Mars Local Time (M.L.T.): 15:55 (Middle Afternoon)
Latitude (centered): 79,5° South
Longitude (East): 109,4°
Range to target site: 249,2 Km
Original image Scale Range: 49,9 cm/pixel (with 2 x 2 binning) so objects ~150 cm across are resolved
Map Projected Scale: 50 cm/pixel
Map projection: POLAR STEREOGRAPHIC
Emission Angle: 3,5°
Phase Angle: 57,4°
Solar Incidence Angle (S.I.A.): 60°, with the Sun about 30° above the Local Horizon
Solar Longitude: 264,8° - Northern AutumnMareKromium
|
|
PSP_005419_1380_RED_browse-00.jpgFlow-like Features in Promethei Terra (context frame)54 visiteThis image, part of the south-facing slopes of a massif in Promethei Terra in the Southern Highlands, shows flow-like features (tongue-shaped lobes, parallel ridges) that indicate movement of surface materials downhill and towards the South-West, following the regional slope.
The difference in elevation between the ridge (near the top or northern-most portion of the image) and the valley (to the South) is over 2200 meters (7,200 feet).
These flow-like features are reminiscent of those observed in terrestrial landslides and rock glaciers , in which the downhill movement of rocks and soils is facilitated by an agent (most commonly water in landslides, ice in glaciers) that acts as a lubricant and provides cohesion. Theoretical calculations predict that under current and recent Martian climate conditions, neither water nor ice would be stable near the surface for extended periods of time in this Region.
The temperatures are so low that water would freeze, and then quickly sublime, because the air is very thin and dry. Ice could, though, be stable at present approximately 1 meter (3 feet) or more below the surface.
MareKromium
|
|
PSP_005419_1380_RED_browse-01.jpgFlow-like Features in Promethei Terra (extra-detail mgnf)53 visiteThe subimage (approx. 390 x 260 meters) shows in detail some of the ridges developed in the slope deposits. Numerous fissures cut through the surface, forming polygons 5 to 10 mt (5,5 to 11 yards) across.
Such well-preserved polygons indicate that the downhill flow had stopped before they formed. Polygonal features similar to these are common in terrestrial periglacial regions such as Antarctica, where ice is present at or near the surface. Antarctica's polygons formed by repeated expansion and contraction of the soil-ice mixture due to seasonal temperature oscillations.MareKromium
|
|
PrometheiPlanum.jpgPromethei Terra (Natural Colors + MULTISPECTRUM; credits: ESA & Lunexit)53 visitePromethei Planum, an area seasonally covered with layer of ice more than 3500 mt thick layer of ice in the Martian South Polar Region, was the subject of the High Resolution Stereo Camera’s focus on 22 September 2005 as Mars Express was in orbit above the Red Planet.
Promethei Planum lies at approx. 76° South Lat. and 105° East Long.
An approx. 100 Km-large and 800 mt-deep impact crater is visible in the Northern part of the image. The crater’s interior is partly covered in ice.
In the centre of the image are structures that may have been created by basaltic lava flow from a volcano. This area is covered in ice. The dark dunes towards the bottom of the image are most likely made up of dust originating from this lava flow or volcanic ash.
A broad sheet of ice, which is an extension of the South Polar Ice Cap is located South of the lava flow. The steep flanks clearly show white, clean ice. The thickness of the ice is between 900 and 1100 mt.MareKromium
|
|
| 8 immagini su 1 pagina(e) |
|
