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M-106.jpgM 106 - Spiral Galaxy61 visite"...Optime positum est beneficium bene ubi meminit qui accipit..."
(P. Siro)
"...Un dono è ben fatto allorchè colui il quale lo riceve, non lo dimentica..." (trad. libera)MareKromium
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ESP_012271_0940_RED_abrowse.jpgSouth Polar "Swiss-Cheese Surface Features" (Natural Colors; credits: Lunar Explorer Italia)61 visiteThis image represents a Martian Terrain containing "Swiss Cheese" features. This Terrain is found only within the residue of the Southern Polar Cap, which comprises of mostly frozen CO2 and H2O.
These particular features are flat-floored, circular depressions that are believed to form from different rates in the seasonal changes of the CO2 and H2O ices. Varying rates in sublimation (when these ices change directly to vapors upon heat and back to deposited solids upon cooling) produces these rimmed depressions from the flat polar ice plane. It is hypothesized that the depression areas are made up of dry ice - such as Carbon Dioxide - and the material below consists of the water ice.
This Carbon Dioxide solid rises and slightly evaporates into the thin Atmosphere in the Summer while the water layer remains in place. As the South Pole cools with seasonal change, the "Swiss Cheese" formation is obtained with risen CO2 rimmed depressions and flat water mesas.
The Martian North Pole will evaporate all of its CO2 in the Summer; however the South Pole is colder and this may explain why this Terrain is only found in this area.
Some of the circular features in the full image show distinct cusps that point in the direction of the Pole. These cusps suggest insolation, a measure of solar radiation that is pushing the movement/formation of these depressions away from the Pole. There is also an observed lateral outward growth of the features at the rate of about 1-to-3 meters a year, indicating to scientists that the depressions must form in a CO2 medium.MareKromium
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ZO-Saturn_New_Moon-S2008-S1-PIA11503.jpgSaturn's New Moon S/2008 S161 visiteCaption NASA:"A bright arc within Saturn's faint G-Ring holds a tiny gift: a small moonlet is just visible as a short streak near the ansa of the G-Ring Arc in the top of two versions of the same image.
The second (bottom) version of the image has been brightened to enhance the visibility of the G-Ring. The other streaks in this version of the image are stars smeared by the camera's long exposure time of 26". This version of the image shows a gap in the G-Ring which was faintly visible in an earlier Cassini movie (see PIA08327).
This view looks toward the sunlit side of the Rings from about 1° below the Ring-Plane. The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on Jan. 28, 2009. The view was acquired at a distance of approx. 1,2 MKM (such as about 746.000 miles) from Saturn and at a Sun-Saturn-Spacecraft, or Phase, Angle of 27°.
Image scale is roughly 7 Km (a little more than 4 miles) per pixel".MareKromium
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APOLLO_15_-_AS15-84-11312_HR.jpgAS 15-84-11312 - Mount Hadley61 visitenessun commentoMareKromium
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APOLLO_15_-_AS15-84-11315_HR.jpgAS 15-84-11315 - Mount Hadley61 visiteCaption NASA:"144:47:51 MT - This frame ends Dave Scott's vertical sequence of pictures of the West Face of Mt. Hadley. It is probably the best picture of the "high water marks" at the base of the mountain".MareKromium
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APOLLO_15_-_AS15-84-11314_HR.jpgAS 15-84-11314 - Mount Hadley61 visitenessun commentoMareKromium
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Panoramic-AS15-84-11310-AS15-84-11315-3.jpgFrom AS 15-84-11310 until 11315 (Mount Hadley - Natural Colors enhanced; credits: Lunar Explorer Italia)61 visitenessun commentoMareKromium
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ESP_013071_1365_RED_abrowse.jpgCentral Peak Gullies (Natural Colors; credits: Lunar Explorer Italia)61 visitenessun commentoMareKromium
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ESP_012926_1365_RED_abrowse.jpgLohse Crater (Natural Colors; credits: Lunar Explorer Italia)61 visiteThis image is of the Eastern half of the Central Peak of Lohse Crater located in the Southern Hemisphere.
The crater itself is highly degraded and is roughly 80 miles in diameter. Of specific interest are the pristine looking Gullies that appear to have sourced from layers below the top of this uplifted region.
Smaller Gullies appear to emanate in all directions from the uplifted region, but of special interest is the larger Gully located on the northern most slope of the Central Peak. This Gully has a larger alcove and a better developed debris apron than surrounding Gullies. This implies that either this gully formed over a longer time period or that more fluid was involved in its formation.
Gullies are present on many slopes on Mars, especially between the latitudes of 30 and 70° in both Hemispheres. Gullies are formed by fluids and have three distinct parts to them: an eroded “alcove” at the top, a sometimes sinuous “channel” section, and finally a large “debris apron” where the material eroded by the Gully is deposited.MareKromium
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Antares_and_Sun.JPGStar-Size!61 visite"...Fortuna parvis momentis magnas rerum commutationes efficit..."
(Cesare)
"...Il Fato, in pochi istanti, può mutare la sorte (l'esito) di grandi imprese..."MareKromium
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Arcturus_and_Sun.jpgStar-Size!61 visite"...Fortuna immoderata (est): in bono atque in malo..."
(Laberio)
"...La Fortuna (il Fato) non ha (mai) misura: nè nel bene, nè nel male..."MareKromium
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ESP_013144_2075_RED_abrowse.jpgCollapse Features on the Flank of Elysium Mons (Natural Colors; credits: Lunar Explorer Italia)61 visiteThis image is of the Flanks of the "Shield Volcano" Elysium Mons. The volcano is considered to be the youngest within the Elysium Mons Province, which also contains the volcanoes Hecates Tholus and Albor Tholus.
Of course, "young" is a relative term. The last eruption of Elysium Mons could well have been a billion years or more ago.
This image shows a series of flat bottomed valleys along the flanks of Elysium Mons. There is considerable debate on exactly how these valleys form. In Hawaii, the classic example of Shield Volcanoes on Earth, similar valleys are carved by prodigious rainfall. While some rain may have fallen in the earliest epochs of Mars' Geologic History, the lack of small drainage networks shows that these Martian Channels were not carved by rain. However, Mudflows and Lava Flows could potentially erode the sides of the Volcano.
An important hint for the origin of the Valleys comes from the Chain of Pits visible in the Northern part of the image. These Pits form as the ground is pulled apart by Marsquakes. Thus it seems that many of these Valleys are first formed by movement along Faults. Then Mud and/or Lava Flows widen the sides of the Valley and give it a flat floor.MareKromium
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