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Titan-Huygens_Landing_Site-12-PIA07870-br500.jpgHuygens Landing Site54 visiteCaption NASA originale:"This stereographic projection of Descent Imager/Spectral Radiometer images from the European Space Agency's Huygens probe combines 60 images in 31 triplets, projected from a height of 3.000 mt (approx. 9.843 feet) above the black 'lakebed' surface. The bright area to the North (top of the image) and West is higher than the rest of the terrain and covered in dark lines that appear to be drainage channels.
The images were then stitched together using one of several projection algorithms (in this case 'stereographic') to produce a full mosaic. The images used to construct this mosaic were taken on Jan. 14, 2005. The Descent Imager/Spectral Radiometer is 1 of 2 NASA-funded instruments on the probe".
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Titan-Huygens_Landing_Site-13-PIA07871.jpgHuygens Landing Site54 visiteCaption NASA originale:"This mosaic from the Descent Imager/Spectral Radiometer camera on the European Space Agency's Huygens probe combines 17 image triplets, projected from an altitude of 800 mt (approx. 2.625 feet).
The area covered is approximately 1,3 Km across (North at the top of the image). The smallest visible objects visible are less than 5 mt across and the dark channels are 30 to 40 meters (approx. 98 to 131 feet) wide.
The images were then stitched together using one of several projection algorithms (in this case 'gnomonic') to produce a full mosaic. The images used to construct this mosaic were taken on Jan. 14, 2005".
Commento: a nostro parere si tratta di immagini complesse (e piuttosto confuse), estremamente difficili da interpretare in maniera convincente (almeno sulla base di ricostruzioni come queste due che Vi abbiamo proposto).
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Titan-Huygens_Landing_Site-14.jpgHuygens' landing site: best estimate63 visiteIn questa immagine il Centro Controllo Missione di Darmstadt ci fornisce la sua "migliore supposizione" (best estimate) sul punto in cui la Sonda Huygens potrebbe trovarsi adesso. Certo, la certezza assoluta sul punto di impatto non potremo averla mai, a meno che, un domani, non si vada direttamente su Titano a cercarla... Comunque sia, le ultime informazioni ricevute ed elaborate ci dicono che Huygens non è caduta nè dentro un mare od un lago di Titano, nè (propriamente) su una superficie rocciosa. La Sonda ESA, a quanto pare, si è adagiata su un'area fangosa, probabilmente in prossimità di un mare (di idrocarburi?).
Huygens, salvo l'occorrere di eventi imprevisti ed imprevedibili, trascorrerà i prossimi millenni esattamente nel punto dove è caduta, su un mondo affascinante - ancorchè gelido e lontano -, a circa - 180°C. La domanda è: andremo mai a riprenderla?!?...
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Titan-IMG001663-br500.jpgTitan from about 209.000 Km (FlyBy n. 6)54 visiteOriginal caption:"This is one of the first images returned from T6, such as the sixth Titan flyby. The image (W00010189.jpg) was taken on August 21, 2005 and received on Earth August 23, 2005. The camera was pointing toward Titan (approx. 209.379 Km away) and the image was taken using the CB3 and IRP90 filters. (...)".
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Titan-IMG001935-PCF-LXTT.jpgTitan during Fly-By n. 9 (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)172 visiteOriginal NASA caption:"This image was taken on December 26, 2005 and received on Earth December 27, 2005. The camera was pointing toward TITAN that, at the time, was approximately 57.509 Km (about 35.734 miles) away.
This image was taken using the CB3 and CL2 filters and has not been validated or calibrated".MareKromium
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Titan-IMG001935-br500.jpgTitan during Fly-By n. 9 (Original NASA/JPL/SSI RAW b/w Frame)58 visiteOriginal caption:"This image was taken on December 26, 2005 and received on Earth December 27, 2005. The camera was pointing toward TITAN that, at the time, was approximately 57.509 Km (about 35.734 miles) away.
This image was taken using the CB3 and CL2 filters and has not been validated or calibrated".
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Titan-IR-PIA07542.jpgInfrared Titan (from approx. 1,2 MKM)56 visiteCaption NASA originale:"Southeast of Xanadu (and above the center in this view) is a peculiar semi-circular feature informally referred to by imaging scientists as "The Smile". This surface feature is the brightest spot on Titan's surface, not only to the Imaging Science Subsystem Cameras, but also to the Visual and Infrared Mapping Spectrometer (VIMS), which sees the surface at even longer wavelengths. "The Smile" is about 560 Km (345 miles) wide.
At the landing site of the successful Huygens probe mission, brighter regions correspond to icy upland areas, while the darker regions are lowlands that possess a higher proportion of the organic byproducts of Titan's atmospheric photochemistry. Those results seem to confirm the long-standing hypothesis that Xanadu is a relatively high region of less contaminated ice. However, the cause of the even brighter Smile is a mystery that is still under study. Farther South, a field of bright clouds arcs around the Pole, moving at a few meters per second".
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Titan-IR.jpgIR Titan (credits: Dr M. Faccin - Lunexit Team)56 visitenessun commentoMareKromium
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Titan-Island-PIA09180.jpgTitanian Sea and Islands in it58 visiteCaption NASA:"This radar image, obtained by Cassini's radar instrument during a near-polar flyby on Feb. 22, 2007, shows a big island smack in the middle of one of the larger lakes imaged on Saturn's moon Titan. This image offers further evidence that the largest lakes are at the highest latitudes.
The island is about 90 Km (approx. 62 miles) by 150 Km (approx. 93 miles) across, about the size of Kodiak Island in Alaska or the Big Island of Hawaii.
The island may actually be a peninsula connected by a bridge to a larger stretch of land. As you go farther down the image, several very small lakes begin to appear, which may be controlled by local topography.
This image was taken in synthetic aperture mode at 700 mt (2300 feet) resolution. North is toward the left. The image is centered at about 79° North Lat. and 310° West Long".
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Titan-Islands-IMG001328-br500.jpgBright white Islands54 visiteCaption NASA originale:"(...) flow around bright 'islands'. The areas below and above the bright islands may be at different elevations". Riprendendo quanto dicevamo in sede di commento al frame precedente, una teoria abbastanza "esotica" - ma da non scartare aprioristicamente - ci dice che la superficie di Titano si è scaldata in epoche (relativamente) remote a seguito di un violentissimo impatto il quale, pur sconvolgendo il pianeta, ha prodotto non solo calore sufficiente a mantenere Titano "caldo" per ere, ma lo ha pure "geologicamente risvegliato".
Dunque su Titano, in accordo a questa teoria, dovremmo trovare svariate fornaci vulcaniche attive, sia superficiali, sia sotterranee. Questo, forse, è il segreto della "vitalità" di Titano.
Purtroppo, come Vi accennavamo, non abbiamo ancora nessuna prova per dare sostanza a questa teoria ma, in fondo, ogni scoperta nasce da un'ipotesi e questa specifica ipotesi, secondo noi, è azzardata, ma NON inverosimile (fonte: ESA).
Voi che ne dite?
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Titan-Lakes-Ontario_Lacus-00-PIA13172.jpgOntario Lacus68 visiteThis image of Ontario Lacus, the largest lake on the Southern Hemisphere of Saturn's moon Titan, was obtained by NASA's Cassini Spacecraft on Jan. 12, 2010.
North is up in this image. Objects appear bright in this radar image when they are tilted toward the Spacecraft or have rough surfaces. The lake surface appears dark because it is smooth. The Northern Shoreline features flooded River Valleys and Hills as high as about 1 Km (3000 feet).
A smooth, wave-sculpted Shoreline, like that seen on the S/Eastern side of Lake Michigan, can here be seen on the N/Eastern side of the lake.
Smooth lines parallel to the current shoreline could be formed by low waves over time, which were likely driven by winds sweeping in from the West or South-West.
The S/Eastern shore features a round-headed Bay intruding into the shore. The liquid-filled depressions appear to be relatively recent.
The middle part of the Western Shoreline shows the first well-developed Delta observed on Titan. The shape of the Delta shows that liquid flowing down from a higher plain has switched Channels on its way into the Lake, forming at least two lobes. Examples of this kind of Channel switching and wave-modified deltas can be found on Earth at the Southern end of Lake Albert between Uganda and the Democratic Republic of Congo in Africa and the remains of an ancient lake known as Megachad in the African country Chad.
Titan is the only other world in our Solar System known to have standing bodies of liquid on its Surface. Because Surface temperatures at the Poles average a chilly 90 Kelvin (about minus 300 degrees Fahrenheit), the liquid is a combination of Methane, Ethane and Propane, rather than water.
Ontario Lacus has a surface area of about 15.000 square Km (approx. 6000 square miles), slightly smaller than its terrestrial namesake, Lake Ontario.MareKromium
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Titan-Lakes-Ontario_Lacus-01-PIA13173.jpgOntario Lacus54 visiteThis is Ontario Lacus, the largest lake on the Southern Hemisphere of Saturn's moon Titan. It is based on overlapping radar images obtained by NASA's Cassini Spacecraft on June 22, 2009, July 8, 2009 and Jan. 12, 2010. The images were synthesized into stereoscopic images by the Cassini radar team.
The Northern Shoreline features low Hills, probably about 1 Km (3000 feet) in altitude, and flooded River Valleys. A smooth, wave-sculpted Shoreline, like that seen on the South-Eastern side of Lake Michigan, can be seen on the North-Eastern side of the Lake.
The South-Eastern shore features a round-headed bay intruding into the shore. The middle part of the Western Shoreline shows the first well-developed delta observed on Titan.
Topography has been vertically exaggerated by a factor of roughly 10 times. Titan's solid Surface and Atmosphere are portrayed in shades of brown, approximating their appearance as measured by the descent imager and spectral radiometer on board the Huygens probe, which landed on Titan in 2005. Scientists surmise the liquid Methane, ethane and propane in the lake would look black to the human eye, but this is a hypothesis based on the best available data.
The Sun was placed low on the horizon, at an angle similar to where it was during the Cassini Fly-Bys.MareKromium
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