| Piú viste - Saturn: the "Ringed Beauty" and His Moons |
Stars-N00068672.jpgStar-trails & Cosmic Rays, from Cassini107 visitenessun commento
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Japetus-PIA08375~0.jpgSnow on Japetus' Mountains (Natural Colors; credits: Lunar Explorer Italia)107 visiteDopo aver effettuato la consueta colorizzazione Multispettrale ed in Colori Naturali, la nostra idea è che le chiazze bianche e dai riflessi blu che caratterizzano alcuni rilievi della misteriosa Luna Saturniana Giapeto debbano essere riferiti a ghiaccio d'acqua (la cui albedo e specifica colorazione lo rende inconfondibile).
Pronti a scusarci in caso di errore, rimettiamo la parola ai nostri Amici di Pasadena (che, sino ad oggi, sull'argomento in questione non si sono sbilanciati).MareKromium
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Tethys.pngTethys and the Sun (possible Natural Colors; credits for the additional process. and color.: Marco Faccin and E. Bonora)107 visitenessun commentoMareKromium
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Rhea-N00083837.jpgRhea (b/w)106 visitenessun commentoMareKromium
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Tethys-N00160998-119-EB-LXTT.jpgThe buttered and scarred "Face of Tethys" (Natural Colors; credits for the additional process. and color.: Elisabetta Bonora & Paolo C. Fienga - Lunexit Team)106 visitenessun commentoMareKromium
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Japetus-PIA08384-PCF-LXTT-IPF.jpgEngelier Crater (CTX Frame and EDM in Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)106 visiteThe NASA - Cassini Spacecraft captured, in the month of September of the AD 2007, the first High-Resolution glimpse of the bright Trailing Hemisphere of Saturn's moon Japetus. This Absolute Natural Color image-mosaic shows the entire Hemisphere of Japetus that was visible from the NASA - Cassini Spacecraft on the outbound leg of its encounter with the two-toned moon. Also shown here is the complicated Transition Region of Japetus (meaning the Region which is located in-between its Dark Leading Hemisphere and the Bright Trailing one). This Region, visible along the right side of the image, was observed in many of the images acquired by Cassini near the closest approach of the encounter.
Revealed here for the first time in detail are the Geologic Structures that mark the Trailing Hemisphere of Japetus. The Region appears to be Heavily Cratered, particularly in the North and South Polar Regions of the moon. Near the top of the mosaic, numerous Impact Features that hade been already caught in several frames obtained by the NASA - Voyager 2 Spacecraft during the Fly-By of Japetus that took place in the AD 1981, are well visible, including the Impact Craters Ogier and Charlemagne. However, the most prominent Topographic Feature in this view, in the bottom half of the mosaic, is the approx. 450-Km (such as about 280-miles) wide Engelier Impact Basin: one of at least 9 (nine) huge Impact Basins found on Japetus. In fact, the Engelier Impact Basin overlaps an older, similar-sized Impact Basin located to its South/East.
In many places of Japetus, the Dark Material (that is thought to be composed of Nitrogen-bearing Organic Compounds - called "Cyanides" -, as well as by Hydrated Minerals and other Carbonaceous Minerals) seems to "coat" the Equator-facing Slopes as well as the Floor of the Impact Basin. The distribution of this Dark Material as well as the variations in the color of the Bright Material that is spread all across the Trailing Hemisphere, will be crucial clues to solve (or, at least, ro clarify) if we really want to get a better understanding of the origin of Japetus' extremely peculiar bright-dark dual personality.
The view was acquired with the NASA - Cassini Spacecraft Narrow-Angle Camera on September 10, 2007, at a distance of about 73.000 Km (such as approx. 45.333 miles) from Japetus. This mosaic consists of 60 images covering 15 footprints across the Surface of Japetus. The view is an Orthographic Projection of the Saturnian moon that has been centered at 10,8° South Latitude, 246,5° West Longitude and which has a resolution of 426 meters (0,26 miles) per pixel. An Orthographic Projection (like this one) is something like the view that a distant observer would get by looking at a given Celestial Object through a telescope.
This frame (which is an Original NASA - Cassini Spacecraft false-color image mosaic published on the NASA - Planetary Photojournal with the ID n. PIA 08384) has been additionally processed, contrast enhanced, and then re-colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the bright Trailing Hemisphere of the Saturnian moon Japetus), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present on the Surface of Japetus, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: in the EDM (upper Right Side of the image-mosaic), a view of the Terrain located in the Transition Zone of Japetus. The Bright Material visible on the frozen Surface of Japetus is, most likely, Water Ice, while the Dark Material is, probably, a Carbonaceous Mineral.MareKromium
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AC-Anomaly-Saturn_s Sky.jpgA bright light in the Space of Saturn: Saturn overexposed (2)105 visiteQuesta immagine, ricevuta il giorno 13 Agosto 2004, appare identica a quella ricevuta il giorno 4 Agosto 2004. In teoria, dovrebbe essere Saturno (o il suo anello "E") "altamente sovraesposto". In pratica noi possiamo dire, con onestà, che la sovraesposizione di un corpo luminoso come Saturno dovrebbe dare esiti visivi completamente diversi da quelli che Vi mostriamo in questo frame.
Di che si tratta? Forse del Sole. Forse un'altra sorgente luminosa, molto più vicina. Noi non lo sappiamo, ma abbiamo chiesto lumi alla NASA.
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The_Rings-N00154629-35-EB-LXTT.gifAstrophysics in motion (a GIF-Movie by Elisabetta Bonora - Lunexit Team)105 visitenessun commentoMareKromium
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Dione-EB-MF-LXTT-IPF-2.jpgDione (Enhanced Natural Colors; credits for the additional process. and color.: Elisabetta Bonora and Marco Faccin)105 visitenessun commentoMareKromium
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Saturn-PIA21903-00.jpgThe End....105 visiteCaption NASA originale:"This view of Saturn looks toward thePplanet's Night Side, only lit by Sunlight reflected from the Rings.
A mosaic of some of the very last images captured by Cassini's cameras, shows the location where the Spacecraft would have entered the Planet's Atmosphere a few hours later. An annotated view (see the next frame) marks the entry site with an oval. While this area was on the Night Side of the Planet at the time, it would rotate into daylight by the time Cassini made its final dive into Saturn's Upper Atmosphere, ending its remarkable 13-year exploration of Saturn.
Images taken using red, green and blue spectral filters were combined to show the scene in Near Natural Colors. The images were taken with Cassini's wide-angle camera on Sept. 14, 2017, at a distance of approx. 394.000 miles (such as a little more than 634.000 Km) from Saturn.
The Cassini spacecraft ended its mission on Sept. 15, 2017".MareKromium
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Rhea-PIA12809-PCF-LXTT.jpgThe Heavily Fractured Surface of Rhea (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)104 visiteCaption NASA:"Icy Fractures on Saturn's moon Rhea reflect Sunlight brightly in this High-Resolution Mosaic created from images captured by NASA's Cassini Spacecraft during its March 2, 2010, Fly-By. This Fly-By was the closest one of Rhea up to then.
This mosaic of six images shows the Westernmost portion of the moon's "Wispy" Terrain. Among the interesting features depicted here is a very straight East-West Fracture near the top center of the mosaic that intersects two North-South Fractures. The large Crater at the bottom left of the mosaic is Inmar Crater (about 55 Km, or approx. 34 miles across).
The closest approach of the Spacecraft to Rhea during this encounter was of about 100 Km (approx. 62 miles). These images were obtained approximately 30 minutes later, at an altitude of about 16.000 Km (roughly 10.000 miles).
This mosaic shows part of the side of Rhea that always faces Saturn. The images were re-projected in an orthographic projection centered on Terrain at 7° North Latitude and 296° West Longitude. The mosaic itself shows Features centered on Terrain that is at 6° North Latitude and 293° West Longitude.
The images were taken with the Cassini Spacecraft narrow-angle camera. The view was obtained at a Sun-Rhea-Spacecraft, or Phase, Angle of about 2°. So, Cassini was almost directly between Rhea and the Sun as it acquired these images.
Image scale is roughly 85 meters (280 feet) per pixel".MareKromium
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Saturn-W00015413.jpgSea of Clouds (1)103 visiteCaption NASA:"W00015413.jpg was taken on May 22, 2006 and received on Earth on May 23, 2006. The camera was pointing toward Saturn that, at the time, was approximately 269.602 Km away.
The image was taken using the CB2 and CL2 filters".
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