| Piú viste - Titan: The "Foggy" Moon |
Titan-Atmosphere-N00031071.jpgThe "Foggy" Limb of Titan57 visiteIl 4° fly-by di Titano si è compiuto e dalla Sonda Cassini, come al solito, ci arrivano una marea di frames completamente (o quasi) inesplicabili. Gli artifacts fotografici, come vedete in questo frame che abbiamo scelto fra tantissimi uguali, sono tanti (e la pulitura elettronica delle immagini avverrà solo in un futuro imprecisato); i rilievi della superficie di Titano - come ovvio - sono assolutamente impossibili da cogliere senza l'ausilio di attrezzature e tecniche all'avanguardia. Il risultato, purtroppo, è che noi non siamo in grado di dirVi nulla di "nuovo" su questa comunque affascinante Luna "Nebbiosa". La NASA, come sapete, esprime - di tanto in tanto - qualche commento a riguardo, ma il tutto si esaurisce (come per Marte) in grandi bolle di sapone: pillole di Scienza "usa & getta" che possono essere utili a dei Divulgatori (come noi, per esempio), ma che non servono quasi a nulla nel momento in cui si intendessero fare degli studi e delle ricerche un pò più profondi/e e dettagliati/e.
Peccato...
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Titan-PIA06222_modest.jpgThe Eastern Region of Titan57 visite(...) Best view to date of the Region east of Xanadu Regio. This mosaic (...) reveals new detail of dark expanses and the surrounding brighter terrain. Some of the features seen here are reminiscent of those seen elsewhere on Titan, but the images also reveal new features. In the center of the image (fig. A) lies a bright area completely surrounded by darker material. The northern boundary of the bright "island" is relatively sharp and has a jagged profile, resembling the now-familiar boundary on the western side of XanadU. The profile of the southern boundary is similar. Streamers of bright material extend southeastward into the dark terrain. At the eastern end of the bright "island" lies a region with complex interconnected dark and bright regions (see fig. B). To the south, the bright terrain is cut by fairly straight dark lines. Their linearity and apparently angular intersections suggest a tectonic influence, similar to features in seen in the bright terrain west of Xanadu. Toward the northeastern edge of the dark material a dark, circular spot in the middle of a bright feature (see figure C) is an approximately 80-kilometer-wide (50-mile) crater identified in the February 2005 radar data (see PIA07368 for the radar image).
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Titan-3-PIA06229.jpgTitan in three different wavelenghts: the strange Titan (3)57 visiteCaption NASA originale:"This false-color composite was created with images taken during the Cassini spacecraft's closest flyby of Titan on April 16, 2005.
It was created by combining 2 infrared images (taken at 938 and 889 nnmts) with a visible light image (taken at 420 nnmts). Green represents areas where Cassini is able to see down to the surface. Red represents areas high in Titan's stratosphere where atmospheric methane is absorbing sunlight. Blue along the moon's outer edge represents visible violet wavelengths at which the upper atmosphere and detached hazes are better seen.
A similar false-color image showing the opposite hemisphere of Titan was created from images taken during Cassini's first close flyby of the smoggy moon in October 2004 (see PIA06139). At that time, clouds could be seen near Titan's South Pole, but in these more recent observations no clouds are seen. North on Titan is up and tilted 30° to the right".
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Titan-4-PIA06227.jpgTitan in three different wavelenghts: is it always Titan?57 visiteCaption NASA originale:"All of these images were taken with the Cassini spacecraft wide angle camera on April 16, 2005, at distances ranging from approximately 173.000 to 168.200 Km (such as approx. 107.500 to 104.500 miles) from Titan and from a Sun-Titan-spacecraft angle of 56°.
Resolution in the images approximately 10 Km per pixel".
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Titan-Atmosphere-IMG001498-br500.jpgComplex Hydrocarbons in Titan's upper atmosphere57 visiteCaption NASA originale:"During its closest flyby of Saturn's moon Titan on April 16, the Cassini spacecraft came within 1.025 Km of the moon's surface and found that the outer layer of the thick, hazy atmosphere is brimming with complex hydrocarbons.
This figure shows a mass spectrum of Titan's ionosphere near 1.200 Km above its surface. The mass range covered goes from Hydrogen at 1 atomic mass unit per elementary charge (Dalton) to 99 Daltons. This mass range includes compounds with 1, 2, 3, 4, 5, 6 and 7 carbons as the base structure (as indicated in the figure label). The identified compounds include multiple carbon molecules and carbon-nitrogen bearing species as well".
Un'atmosfera "primordiale", dunque, ma teoricamente idonea per lo sviluppo di forme di vita 'prossime' (in termini di fondamenta chimiche e chimico/fisiche) alle nostre concezioni di 'forme vitali'.
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Titan-Volcano-02.jpgThe Titanian Volcano (3)57 visiteCaption NASA originale:"From infrared images that show variations in brightness and texture, a geological map of a 'possible Titanian volcano', has been obtained using Cassini's VIMS. This geologic map shows that the circular feature has what appear to be several series of flows, as shown by the black lines. The flows represent episodes of activity on the volcano. A dark central pit, called a caldera, is similar to vents (----> aperture da sfogo; crepacci che fungono da sfogo) that appear above reservoirs of molten material on Earth's volcanoes. The colors on the map represent the brightness of features. Yellow and light green represent bright patches. Blue represents dark patches. Red represents mottled (----> screziato, a chiazze) material. The yellow area is where the volcano lies".
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Titan-PIA07730.jpgTitan, from about 159.000 Km57 visiteThis processed image from Cassini's Aug. 22, 2005, flyby of Titan reveals mid-latitudes on the Moon's Saturn-facing side.
Provisional names recently have been applied to a number of features on Titan. Features within the Region seen here - long known informally as the "H" - now have names like Tsegihi, Aztlan and Quivira.
The bright 215-Km-wide feature provisionally named "Bazaruto Facula" is clearly visible right of center, with its dark, unnamed 80-Km-wide crater at its center.
This view was acquired with the wide-angle camera at a distance of approx. 159.000 Km from Titan using a spectral filter centered on infrared wavelengths at 939 nnmts. The image scale is 9 Km per pixel.
Previous observations indicate that, due to Titan's thick and very hazy atmosphere, the sizes of surface features that can be resolved are a few times larger than the actual pixel scale.
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Titan-PIA07729.jpgTitan, from about 213.000 Km (natural colors)57 visiteAs Cassini approached Titan on Aug. 21, 2005, it captured this natural color view of the moon's orange (nota: veramente, a parte i nostri occhi - che, come tutti sanno, possono sbagliare -, il software che utilizziamo per valutare la densità cromatica dei frames NASA che pubblichiamo e che ci permette altresì di identificare i 'colori maggiori' che sono presenti in essi ci dice che il colore dominante è il "giallo"...), global smog. Titan's hazy atmosphere was frustrating to NASA Voyager scientists during the first tantalizing Titan flybys 25 years ago, but now Titan's surface is being revealed by Cassini with startling clarity (...).
Images taken with the wide-angle camera using red, green and blue spectral filters were combined to create this color view. The images were acquired at a distance of approximately 213.000 Km from Titan and at a Sun-Titan-spacecraft, or phase, angle of 55°. Resolution in the image is about 13 Km per pixel.
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Titan-Dunes-PIA03567.jpgTitanian Dunes57 visiteOriginal caption:"Large areas of this Cassini synthetic aperture radar image of Titan are covered by long, dark ridges. They resemble the "cat scratches" seen in other places on Titan, but here they are longer and straighter. Spaced about 1 to 2 Km apart, they curve slightly around teardrop-shaped bright terrain, giving the impression of a Japanese garden of sand raked around boulders. The bright material appears to be high-standing rough material that the ridges bend around. This suggests that the ridges are dunes that winds have blown across the surface of Titan from left to right (roughly West to East).
This image was taken during the ninth Titan flyby on Oct. 28, 2005, (the fourth flyby for Cassini's synthetic aperture radar), at a distance of about 1300 Km (about 800 miles).
The image covers an area roughly 140 by 200 Km. It is located 13° South Lat. and 300° West Long.".
Nota: il vero mistero è 'dove' e 'come' la NASA abbia visto ed interpretato i rilievi in questione come possibili dune...
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Titan-Regions-Fensal_and_Aztlan_Region-PIA07634.jpgFensal-Aztlan Region57 visiteOriginal caption:"The H-shaped region Fensal-Aztlan is faintly visible on Saturn's murky moon Titan in this enhanced clear-filter view from Cassini.
While most of the light passing through the clear filters is visible light, a small portion of the light is in the treasured infrared windows that allow views down to the moon's frigid surface (nota: la NASA persiste nel definire Titano come un mondo "gelido". Forse è vero - a logica diremmo di si - ma i dati che possediamo non autorizzano ancora tale conclusione la quale, ovviamente, è ad oggi solo speculativa).
At the upper left, dark wavelike features in the atmosphere encircle the moon's North Pole.
The view shows principally the Saturn-facing Hemisphere on Titan; North is up and rotated 35° to the left.
The image was taken with the Cassini spacecraft narrow-angle camera on Oct. 7, 2005, at a distance of approximately 2,4 MKM (about 1,5 MMs) from Titan and at a phase angle of 33°. The image scale is 14 Km (about 9 miles) per pixel".
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Titan-W00012695.jpgTitans... (2)57 visiteOriginal caption:"W00012695.jpg 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 25.404 Km away.
Te image was taken using the CL1 and RED filters".
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Titan_and_Tethys-N00048632.jpgDancing in the dark: Tethys and Titan57 visitenessun commento
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