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Titan-PIA06138_modest.jpgTitan: the anomalous "circular" surface features are "camera artifacts"53 visiteCaption NASA originale from Planetary Photojournal:"The large, bottom image shows a complex interplay between dark and bright material on Titan's surface. This image was taken at a range of about 340.000 Km and the entire view is approximately 2.000 Km across. The surface appears to have been shaped by multiple geologic processes. Although a few "circular features" can be seen, there are no features that can be definitively identified as impact craters. The 3 smaller images show details of some of the features seen within the larger scene. The image on the upper right shows a scene approximately 500 Km across in which bright and dark bands of material span Et to Wt. The upper middle and upper right images show bright material surrounded by dark material in scenes approximately 300 Km across. The dark circular feature that appears at the top of each of the upper images is an artifact that was not removed by the preliminary image processing. There are no shadows or topographic shading visible in these images".
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Titan-PIA06139-PCF-LXTT-1.jpgTitan (Enhanced Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)182 visitenessun commentoMareKromium
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Titan-PIA06139.jpgTitan (false colors)53 visiteDa "NASA - Picture of the Day" del 28.10.2004:"Normally hidden by a thick, hazy atmosphere, tantalizing features on Titan's surface appear in this false-color view. The image was recorded as the Cassini spacecraft approached its first close flyby of Saturn's smog-shrouded moon on October 26. Here, red and green colors represent specific infrared wavelengths absorbed by Titan's atmospheric methane while bright and dark surface areas are revealed in a more penetrating infrared band. Ultraviolet data showing the extensive upper atmosphere and haze layers is seen as blue. Sprawling across the 5.000 Km wide moon, the bright continent-sized feature known as "Xanadu" is near picture center, bordered at the left by contrasting dark terrain.
Saturn orbiter Cassini and Titan lander Huygens plan further explorations, but for now the origin and nature of Titan's surface features remain unknown".
...Unknown, per ora, diciamo noi...
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Titan-PIA06151_modest.jpgTitan from about 810.000 Km54 visiteCaption NASA originale:"The bright and dark regions near the center of the frame are features on Titan's surface. The image has been processed to make features more visible. The surface contrast is degraded toward the edges of the disk due to the effects of Titan's smoggy atmosphere. The region seen here is similar to that seen during Cassini's first close flyby of Titan in October. The bright area toward the bottom of the image is the region dubbed "Xanadu." North is to the upper right.
The image was acquired at a distance of approximately 810.000 Km and the image scale is 4.8 Km per pixel". Ed ora una curiosità: guardate il bordo di Titano, in alto alla Vostra Dx, ad ore 2, c'è un rilievo rotondeggiante (una "cupola scura") perfettamente visibile. Non sembra un difetto della foto o un artifact derivante da vizio di processo e/o di compressione dell'immagine. E allora, secondo Voi, che cos'è?
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Titan-PIA06183.jpgThe "yellow face" of Titan (natural colors)53 visiteCaption NASA originale:"There is a slight difference in brightness from Northern to Southern hemisphere of Titan, a seasonal effect that was noted in NASA's Voyager spacecraft images, and is also clearly visible in some of the infrared images from Cassini (see http://photojournal.jpl.nasa.gov/catalog/PIA06121).
The Northern polar region is largely in darkness at this time.
This image was taken with the Cassini spacecraft wide angle camera through using red, green and blue spectral filters were combined to create this natural color view. The image was acquired at a distance of approximately 229.000 Km from Titan and at a phase, angle of 20°. Resolution in the image is about 14 Km per pixel".
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Titan-PIA06186.jpgTitan (almost) naked, from 2,5 MKM56 visiteCaption NASA originale:"Titan's surface and atmospheric features are shown here in this processed, visible-light image taken by Cassini. Cassini's visible-light spectral filter is sensitive to a broad range of light, from ultraviolet to near-infrared. Imaging scientists normally use a narrow-band filter centered at 938 nanometers to look at Titan's surface and cloud features. Most images of Titan taken between flybys are in visible light and are used to navigate the spacecraft. Views like these demonstrate that the surface, as well atmospheric features (such as the haze banding seen near the northern limb of Titan), can indeed be seen through this filter. Although the clear filter is not the best way to view the surface, this observation demonstrates that with sufficient processing, this filter can be used to keep track of cloud features during periods between flybys in order to provide a better understanding of the evolution of Titan's atmosphere as the moon nears spring in the northern hemisphere".
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Titan-PIA06220.jpgA New Continent on Titan (from 130.000 up to 146.000 Km)54 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 Titan55 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-PIA06980_modest.jpgTitan: a "Secret Dream" for the Oil Companies"?54 visiteTitano, a quanto è emerso sino ad ora, potrebbe davvero essere (o diventare) un "sogno" per le grandi Multinazionali Petrolifere del nostro Pianeta. Perchè? Osservate il grafico e leggete le note originali NASA...:"This graph shows data acquired by Cassini as it flew by Titan at an altitude of 1.200 Km on Oct. 26, 2004 - its closest approach yet to the Hazy Moon. The data is from Cassini's ion and neutral mass spectrometer, which detects charged and neutral particles in the atmosphere. The graph reveals a diversity of hydrocarbons in the high atmosphere above Titan, including benzene and diacetylene". Ora, una delle tante (e neanche tanto nascoste...) verità che giacciono alle spalle dell'esplorazione spaziale, è nella ricerca di fonti energetiche significative e sfruttabili. Titano sembra proprio essere un Pianeta costituito - prevalentemente - da idrocarburi. La domanda è: premesso che un interesse commerciale può esistere, come fare a sfruttare le risorse di Titano in maniera economicamente vantaggiosa?
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Titan-PIA06982_modest.jpgTitan from 1.200 Km54 visiteCaption NASA originale:"These images show the surface of Titan at two different infrared wavelengths. They were captured by the visual and infrared mapping spectrometer onboard Cassini as the spacecraft flew by at an altitude of 1200 Km - Cassini's closest approach yet to the Hazy Moon. The image on the left, taken at a wavelength of 2 microns, is the most detailed picture to date of the Titan's surface. It reveals complex landforms with sharp boundaries, which scientists are eager to further study. The image on the right was taken at a wavelength of 1 micron and shows approximately what a digital camera might see". Ad essere sinceri, da queste primissime immagini ravvicinate non riusciamo a distinguere praticamente nulla. Dobbiamo attendere che al Controllo Missione elaborino meglio le immagini giunte sino ad ora prima di lanciarci in nuove speculazioni relative alla configurazione effettiva della superficie di Titano. Abbiamo atteso anni, possiamo aspettare ancora qualche settimana...
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Titan-PIA06983_modest.jpgTitan (false colors) + the Huygens' probe landing site56 visiteCaption NASA originale:"This image taken by Cassini's visual and infrared mapping spectrometer clearly shows surface features on Titan. It is a composite of false-color images taken at three infrared wavelengths: 2 microns (blue); 2.7 microns (red); and 5 microns (green). A methane cloud can be seen at the south pole (top of image). This picture was obtained as Cassini flew by Titan at altitudes ranging from 100.000 to 140.000 Km (88.000 to 63.000 miles), less than two hours before the spacecraft's closest approach. The inset picture shows the landing site of Cassini's piggybacked Huygens probe".
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Titan-PIA06987_modest.jpgTwo Views of Titan's Haze54 visiteCaption NASA originale:"These images show 2 views of Titan's planet-wide stratospheric haze just before (left) and after (right) Cassini's first close encounter with the Shrouded Moon. The image on the left was taken on Oct. 25, 2004, through an ultraviolet filter, which is sensitive to scattering of sunlight by small haze particles. It shows the high-altitude haze at the North Pole (top) illuminated above a surface blanketed in darkness during this winter season. Numerous striations are visible in the haze, indicating either waves passing through the layer or the presence of multiple layers.
The image on the right was taken on Oct. 26, 2004 and shows Titan's night-side backlit by the Sun, after Cassini's closest approach to the moon. The haze layer ringing the planet is illuminated because the small particles scatter significant sunlight in the forward direction. Variations in haze concentration and thickness around the globe are also evident and seem to be symmetric around the north pole (upper left)".
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