| Ultimi arrivi - Titan: The "Foggy" Moon |
Titan-Craters-Unnamed_Craters-PIA10655.jpgTitanian Craters (Impact Craters?) - radio-image; credits: NASA56 visiteCaption NASA:"This side-by-side view shows a newly discovered impact crater (at left) compared with a previously discovered crater (at right). The new crater was just discovered by the Cassini Spacecraft's Radar Instrument during its most recent Titan flyby on May 12, 2008. This makes the fourth feature definitely identified as an impact crater so far on Titan -- fewer than 100 features are regarded as possible impacts. Compared with Saturn's other moons, which have many thousands of craters, Titan's surface is very sparsely cratered. This is in part due to Titan's dense atmosphere, which burns up the smaller impacting bodies before they can hit the surface. Geological processes, such as wind-driven motion of sand and icy volcanism, may also wipe out craters.
Both images are about 350 Km (approx. 217 miles) in width.
The crater on the right was discovered by Cassini in 2005 and is shown here for comparison. It is about 80 Km (approx. 50 miles) in diameter, with the radar illumination from above.
Called "Sinlap", this crater is estimated to be about 1300 meters (984 feet) deep.
The new feature pictured on the left, which has not been named yet, is bigger than the Sinlap Crater with a diameter of about 112 Km (approx. 70 miles).
The new crater is located at about 26° North Latitude and 200° West Longitude, in the bright Region known as Dilmun, about 1000 Km (approx. 600 miles) north of the Huygens Landing Site.
In its image, also illuminated from above, it appears slightly irregular, suggesting that it was modified after it was formed, perhaps by collapses of segments of its rim onto the floor.
The crater floor appears flat, and two small bright spots indicate a likely central peak complex.
The ejecta blanket (surrounding material) from this crater is less prominent than that of the Sinlap Crater.
The crater's more degraded character suggests it could be older than Sinlap (assuming that erosive processes are the same at both locations, which are at similar latitudes)".MareKromiumMag 24, 2008
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Titan-PIA10243.jpgUnder the Fog...106 visiteCaption NASA:"This graphic depicts a cross-section of the Saturnian moon Titan. Cassini scientists speculate there may be a layer of liquid water mixed with ammonia about 100 Km (approx. 62 miles) below the surface of Titan.
The assumption that Titan contains an internal ocean was generated from data gleaned from Cassini's Synthetic Aperture Radar during 19 separate passes over Titan between October 2005 and May 2007. Using data from the radar’s early observations, the scientists and radar engineers established the locations of 50 unique landmarks on Titan's surface. They then searched for these same lakes, canyons and mountains in the reams of data returned by Cassini in its later flybys of Titan. What they found was prominent surface features seemed to shift from their expected positions by up to 31 Km (about 19 miles). Since the features could not have really moved, the apparent shift told the scientists and engineers that Titan was spinning about its axis in a previously unsuspected manner. The pre-Cassini model of Titan's spin accounted for the gravitational fields of Saturn and other nearby planets and moons but omitted other smaller less well understood effects. Since the observed spin of Titan does not fit this model, other influences, such as the seasonal changes in the motion of its atmosphere must also be important. It is difficult to explain how such relatively low energy phenomena could have such a pronounced influence on Titan's spin unless the moon's icy crust was decoupled from its core by an internal ocean. If the crust were decoupled from the core, atmospheric fluctuation alone could account the observed spin".MareKromiumMar 21, 2008
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Titan-PIA09858.jpgTitan approaches Saturn (natural colors; credits: NASA)89 visiteCaption NASA:"Swathed in its thick blanket of atmosphere, frigid Titan approaches the brilliant limb of Saturn. This view was obtained just minutes after the wide-angle view, "Father and Son".
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were acquired with the Cassini spacecraft narrow-angle camera on Jan. 29, 2008 at a distance of approx. 2,3 MKM (such as about 1,4 MMs) from Titan.
Image scale is roughly 14 Km (about 8 miles) per pixel".MareKromiumMar 14, 2008
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Titan-PIA09846.jpgAlien Weather (False Colors; credits: Lunexit)106 visiteA bright streak of cloud graces the Northern Skies of Titan.
This is the second time the Cassini spacecraft's imaging cameras have spotted clouds at 60° North Latitude on Titan - the previous occasion being the Feb. 2007 observations during which the cameras saw the dark, hydrocarbon lakes that cover much of the North.
That cloud feature is visible at the bottom of the still image in Exploring the Wetlands of Titan. The circular, 400-Km wide impact feature Menrva can be seen near center.
North on Titan is up and rotated 26° to the right.
The image was taken with the Cassini spacecraft narrow-angle camera on Jan. 20, 2008 using a combination of spectral filters sensitive to wavelengths of polarized infrared light centered at 938 and 746 nanometers. The view was acquired at a distance of approx. 1,3 MKM (800.000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 58°. Image scale is roughly 8 Km per pixel. Due to scattering of light by Titan's hazy atmosphere, the sizes of surface features that can be resolved are a few times larger than the actual pixel scale".MareKromiumMar 01, 2008
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Titan-PIA09833-00.jpgTitan, from 213.000 Km (1 - RAW b/w; credits: NASA)57 visiteCaption NASA:"Titan's hazy orange globe hangs before the Cassini spacecraft, partly illuminated - a world with many mysteries yet to be uncovered.
North on Titan is up and rotated 30° to the right. The moon's North Pole tilts slightly away from the Spacecraft here.
This view was obtained at a distance of approx. 213.000 Km (such as about 133.000 miles) from Titan and at a Sun-Titan-Spacecraft, or phase, angle of 128°.
Image scale is roughly 13 Km (about 8 miles) per pixel".MareKromiumFeb 09, 2008
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Titan-PIA09833-01.jpgTitan, from 213.000 Km (2 - natural colors; credits: NASA)58 visiteCaption NASA:"Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were taken with the Cassini spacecraft wide-angle camera on Jan. 5, 2008". MareKromiumFeb 09, 2008
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Titan-PIA09833-02.jpgTitan, from 213.000 Km (3 - natural colors; credits: Lunexit)86 visitenessun commentoMareKromiumFeb 09, 2008
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Titan-Atmosphere-N00098823.jpgThe "Multi-Layered" Atmosphere of Titan (MULTISPECTRUM - Overexposed; credits for the additional process. and color.: Lunexit)58 visiteCaption NASA:"N00098823.jpg was taken on December 20, 2007 and received on Earth December 22, 2007. The camera was pointing toward TITAN that, at the time, was approx. 186.227 Km away, and the image was taken using the CL1 and UV3 filters. This image has not been validated or calibrated".MareKromiumDic 23, 2007
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Titan_and_Saturn-PIA08398.jpgIn-Transit...55 visiteThe murky orange disk of Saturn's moon Titan glides past -- a silent, floating sphere transiting Saturn.
Titan's photochemical smog completely obscures the surface in such natural color views. Its high-altitude hazes are visible against the disk of Saturn as they attenuate the light reflected by the Planet.
This view was acquired from less than 1° above Saturn's Ring-Plane.
Images taken using red, green and blue spectral filters were combined to create this natural color view. The images were obtained with the Cassini spacecraft narrow-angle camera on Aug. 1, 2007, at a distance of approx. 2,4 MKM (such as about 1,5 MMs) from Titan. Image scale is roughly 15 Km (about 9 miles) per pixel.MareKromiumOtt 17, 2007
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Titan-PIA08391.jpgHiding behind the Rings57 visiteCassini delivers this stunning vista showing small, battered Epimetheus and smog-enshrouded Titan, with Saturn's A and F-Rings stretching across the scene.
The color information in the colorized view is completely artificial: it is derived from red, green and blue images taken at nearly the same time and phase angle as the clear filter image. This color information was overlaid onto the previously released clear filter view in order to approximate the scene as it might appear to human eyes.
The prominent dark region visible in the A-Ring is the Encke Gap (about 325 Km, or 200 miles wide), in which the moon Pan and several narrow ringlets reside. Moon-driven features which score the A-Ring can easily be seen to the left and right of the Encke Gap.
A couple of bright clumps can be seen in the F-Ring.
Epimetheus is 116 Km (72 miles) across and giant Titan is 5.150 kilometers (3.200 miles) across.
The view was acquired with the Cassini spacecraft narrow-angle camera on April 28, 2006, at a distance of approx. 667.000 Km (about 415.000 miles) from Epimetheus and 1,8 MKM (about 1,1 MMs) from Titan. The image captures the illuminated side of the Rings. The image scale is roughly 4 Km (about 2 miles) per pixel on Epimetheus and about 11 Km (approx. 7 miles) per pixel on Titan.MareKromiumOtt 17, 2007
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Titan-W00036545.jpgThe "uneven" Haze of Titan (possible Natural Colors - elab. Lunexit)75 visiteNoi osserviamo le immagini e quindi ci poniamo domande. Eccone una, per noi e per Voi: può essere che sia la cosiddetta "super-rotazione" delle nuvole di Titano la (sola o, se non altro, la maggior) causa delle - evidenti - irregolarità che caratterizzano gli strati più alti della sua atmosfera? Avete opinioni al riguardo?
Scriveteci e/o commentate!MareKromiumOtt 04, 2007
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Titan-N00091161.jpgTitan57 visiteCaption NASA:"N00091161.jpg was taken on September 02, 2007 and received on Earth September 03, 2007. The camera was pointing toward TITAN that, at the time, was approximately 1.313.086 Km away, and the image was taken using the CL1 and UV3 filters. This image has not been validated or calibrated".MareKromiumSet 04, 2007
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