| Piú viste - Titan: The "Foggy" Moon |
Titan-PIA06220.jpgA New Continent on Titan (from 130.000 up to 146.000 Km)59 visiteCaption NASA originale:"This view of Titan uncovers new territory not previously seen at this resolution by Cassini's cameras. The view is a composite of 4 nearly identical wide-angle camera images, all taken using a filter sensitive to wavelengths of infrared light centered at 939 nnmts. The individual images have been combined and contrast-enhanced in such a way as to sharpen surface features and enhance overall brightness variations. Some of the territory in this view was covered by observations made by the Cassini synthetic aperture radar in October 2004 and February 2005. At large scales, there are similarities between the views taken by the imaging science subsystem cameras and the radar results, but there also are differences. For example, the center of the floor of the approximately 80-kilometer-wide (50-mile) crater identified by the radar team in February (near the center in this image, see PIA07368 for the radar image) is relatively bright at 2.2 centimeters, the wavelength of the radar experiment, but dark in the near-infrared wavelengths used here by Cassini's optical cameras. This brightness difference is also apparent for some of the surrounding material and could indicate differences in surface composition or roughness".
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Titan-PIA06222_modest.jpgThe Eastern Region of Titan59 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-2-PIA06230.jpgTitan in three different wavelenghts: the natural Titan (2)59 visiteCaption NASA originale:"This natural color composite was taken during the Cassini spacecraft's April 16, 2005, flyby of Titan. It is a combination of images taken through three filters that are sensitive to red, green and violet light.
It shows approximately what Titan would look like to the human eye: a hazy orange globe surrounded by a tenuous, bluish haze. The orange color is due to the hydrocarbon particles which make up Titan's atmospheric haze. This obscuring haze was particularly frustrating for planetary scientists following the NASA Voyager 1 and 2 mission encounters in 1980-81. Fortunately, Cassini is able to pierce Titan's veil at infrared wavelengths (see also PIA06228). North on Titan is up and tilted 30° to the right".
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Titan-Atmosphere-IMG001498-br500.jpgComplex Hydrocarbons in Titan's upper atmosphere59 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-PIA07878-Titan_sOddSpot.jpgThe "Odd-Spot" on Titan (detail mgnf)59 visiteLa 'Nuvola Permanente': una nuova ed incredibile scoperta su Titano che apre nuovi orizzonti ai panorami di pseudo-certezze che la maggior parte dei Ricercatori si stavano costruendo relativamente a questa "Terra in fieri" (una bella definizione per Titano, nata dopo che sono stati visionati i frames relativi ai primi passaggi ravvicinati della Sonda Cassini e dopo il landing dell'Huygens Probe).
Alla NASA hanno già fatto delle ipotesi; qualcuna plausibile - un uragano permanente - e qualche altra, diciamo così... , un pò "forzata" - tipo la vetta luminosa di una mega-montagna.
E se fosse un 'pennacchio' di fumo, ceneri e polveri - spesso e denso - proveniente da un vulcano attivo (il 'cuore caldo' del Pianeta...)?
E' così improponibile pensare ad un vulcano e, quindi, ad un Pianeta geologicamente attivo?!?
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Titan-Volcano-01-PIA07961.jpgThe Titanian Volcano (2)59 visiteCaption NASA originale:"Details of the circular feature, that scientists think is an ice volcano, which could be a source of methane in Titan's atmosphere, show up at wvlgts larger than 1,3 microns (1 micron is one-millionth of a meter; 1 meter is 39"). The first 6 panels are images of the feature taken in 6 infrared windows. Images made up of two colors (ratio images) are represented in order to visualize compositional variations, which appear to be slight. The last panel is a color composite image (red, 2,75 micron; green, 2 micron; blue, 1,6 micron). These images were acquired with Cassini's VIMS. Titan, Saturn's largest moon, is the only known moon to have a significant atmosphere, composed primarily of Nitrogen, with CH4 (about 2/3%) as the largest remaining component. One goal of the Cassini mission is to find an explanation for what is replenishing and maintaining this atmosphere".
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Titan-Volcano-03-PIA07962.jpgThe Titanian Volcano (4)59 visiteCaption NASA originale:"This HR infrared image was (...) obtained by Cassini's VIMS and shows a bright, circular feature (8,5° Lat.; -143,5° Long.) with two elongated wings extending westwards".
Dunque: anche se i commenti NASA sono veramente 'minimalisti' (ai limiti del ridicolo), sembra ormai chiaro che su Titano esiste una 'fornace attiva' di un qualche tipo. Al di là delle riflessioni che già si potrebbero avviare sulla incompletezza della nostra Scienza e sulle conseguenti stupidaggini dette e scritte in passato a proposito di questo Pianeta, possiamo dire che siamo davanti, in ogni caso, ad un'evidenza incontestabile del fatto che Titano è un mondo 'geologicamente vivo e vegeto'. Vi sembra questa una notizia da poco?
Adesso, a nostro parere, tutti noi (Ricercatori e Scienziati) abbiamo una buona base fattuale per fare autocritica ed iniziare a rivedere le nostre cognizioni in materia di Scienze Planetarie e Dinamiche Evolutive dei corpi celesti ma...avremo l'umiltà per farlo?!?
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Titan-Cryovolcanism-02.jpgCryovolcanism on Titan? (3)59 visiteInsomma: è più "credibile" che la nostra Scienza sia ancora fortemente limitata ed il nostro Sapere ancora - purtroppo - molto lontano dal potersi definire capace di interpretare con assoluta accuratezza una buona parte dei fenomeni che accadono nel nostro (piccolo) Sistema Solare e quindi nell'Universo oppure dobbiamo arrenderci all'idea che ormai 'abbiamo capito tutto' (o 'quasi tutto'...) e che ogni fenomeno è spiegabile facendo ricorso ad una macchina fotografica, ad uno spettrometro ad infrarossi ed a qualche altro aggeggio elettronico dalla sigla impossibile a pronunciarsi?
Scienza non è solo calcolo ma è anche (e forse soprattutto...) riflessione, umiltà, senso comune, capacità di meravigliarsi, capacità di dire - talvolta - "non sappiamo, non abbiamo idea di che cosa stiamo guardando".
Pensateci sopra...
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Titan-Lakes-South_Polar_Lake-01-PIA06241-PCF-LXTT-IPF-000.jpgOntario Lacus and the South Polar Regions of Titan59 visiteCaption NASA originale:"Although it is far too cold for blossoming flowers, summer does bring storm clouds and presumably rain to Titan's south polar region.
The observed persistence of convective storm activity in the region during the Southern Titan Summer has led scientists to speculate that the dark, footprint-shaped feature near the upper left could be a past or present reservoir for Titan's methane rains".
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Titan-PIA07729.jpgTitan, from about 213.000 Km (natural colors)59 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-PIA07774.jpgCrescent Titan59 visiteWith its thick, distended atmosphere, Titan's orange globe shines softly, encircled by a thin halo of purple light-scattering haze. Images taken using blue, green and red spectral filters were used to create this enhanced-color view; the color images were combined with an ultraviolet view that makes the high-altitude, detached layer of haze visible.
The ultraviolet part of the composite image was given a purplish hue to match the bluish-purple color of the upper atmospheric haze seen in visible light.
Small particles that populate high hazes in Titan's atmosphere scatter short wavelengths more efficiently than longer visible or infrared wavelengths, so the best possible observations of the detached layer are made in ultraviolet light.
The images in this view were taken by the Cassini narrow-angle camera on May 5, 2005, at a distance of approx. 1,4 MKM (about 900.000 miles) from Titan and at a phase angle of 137°.
Image scale is 8 Km (5 miles) per pixel.
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Titan-W00013114.jpgThe first clouds of the New "Titan" Year59 visiteOriginal caption:"W00013114.jpg was taken on January 15, 2006 and received on Earth January 16, 2006. The camera was pointing toward Titan that, at the time, was approximately 25.495 Km away, and the image was taken using the CB3 and CL2 filters.
This image has not been validated or calibrated".
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