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| Piú viste - Titan: The "Foggy" Moon |
Titan-Clouds-PIA13400.jpgTitanian Clouds (False Colors; credits: NASA/JPL/University of Arizona/University of Nantes/University of Paris Diderot)92 visiteCaption NASA:"This pair of false-color images, made from data obtained by NASA's Cassini Spacecraft, shows clouds covering parts of Saturn's moon Titan in yellow. Based on the way Near-InfraRed channels of light were color-coded, cloud cover appears yellow, while Titan's hazy Atmosphere appears magenta. The images show cloud cover dissolving from Titan's North Polar Region between May 12, 2008 (left), and Dec. 12, 2009 (right). The clouds in the second image appear around 40° South Latitude, still active late after Titan's Equinox.
Cassini's first observations of clouds near this Latitude occurred during Summer in the Southern Hemisphere. Equinox, when the Sun shone directly over the Equator, occurred in August 2009. It brought a changing of the seasons, as Titan moved out of Southern Summer into Northern Spring.
For the past 6 years, Cassini has observed clouds clustered in three distinct Latitude Regions of Titan: large clouds at the North Pole, patchy cloud at the South Pole and a narrow belt around 40° South. Now scientists are seeing evidence of seasonal circulation turnover at Titan. Clouds at the South Pole disappeared just before Equinox and the clouds in the North are thinning out. This activity agrees with models that predict cloud activity reversing from one Hemisphere to another.
During Winter in the Northern Hemisphere, Northern Polar Clouds of Ethane formed in Titan's Troposphere, the lowest part of the Atmosphere, from a constant influx of Ethane and Aerosols from a higher part of the Atmosphere known as the Stratosphere.
In the Southern Hemisphere, atmospheric gases enriched with Methane welled up from the Surface to produce Mid and High-Latitude Clouds.
The data for the images was detected by Cassini's Visual and InfraRed Mapping Spectrometer in Near-IR wavelengths. Scientists focused on three wavelengths of IR radiation that were particularly good for observing cloud signatures and assigned them red, green and blue channels.
Emissions in the 2 micron wavelength of light, colored red, detect the Titan Surface.
Emissions in the 2,11 micron wavelength, colored green, detect the lowest part of the Titan Atmosphere, or Troposphere.
Emissions at the 2,21 micron wavelength, colored blue, detect the hazy Stratosphere, a higher part of the Atmosphere.
The clouds appear yellowish because they lit up the channels designated red and green, but not the blue channel".MareKromium
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Titan-N00155044-52-56-60-64-71-EB-LXTT.jpgAlmost Full... (Absolute Natural Colors; credits for the additional process. and color.: Elisabetta Bonora - Lunexit Team)91 visitenessun commentoMareKromium
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Titan-River-PIA16197-PCF-LXTT-IPF.jpgTitanian River (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)91 visiteThis image, taken by the NASA - Cassini Spacecraft on September 26, 2012, during its 87th close Fly-By of Titan, shows a vast River System located in the High Northern Regions of this always more intriguing and fascinating Saturnian moon. As a matter of fact, this is the first time that an image coming from Outer Space has revealed what appears to be a true River System that is so vast and structured, anywhere other than on our Home Planet Earth. The River Valley crosses Titan's North Polar Regions and runs directly into the Ligeia Mare: one of the 3 (three) Great Seas that have been so far discovered in the High Northern Latitudes of Titan. This River (still unnamed, but, in a way, very similar to the famous Terrestrial River known as Nile) stretches for more than 200 miles (such as approx. 322 Km).
Scientists have deduced that the River should be filled with actual liquid substances, because (among other things) it appears very dark along its entire extent in this High-Resolution Radar Image: a data, this one, that is indicative of the fact that we are in presence of a smooth Surface. These liquid substances are, presumably, Ethane mixed with Methane, the former having been already positively identified in the AD 2008 by Cassini's Visual and InfraRed Mapping Spectrometer at the Lake known as Ontario Lacus (this one, however, located in Titan's Southern Hemisphere). Even though some short, local Meander (---> a bend in a sinuous watercourse), is visible, the relative straightness of the River Valley suggests that it follows the trace of at least one Fault-line, just like other large Rivers running into the Southern Margin of Ligeia Mare do. Such Faults may lead to the opening of Basins and, perhaps (and in the end), to the formation of the Giant Seas themselves. North is toward the top of the image.
This frame (which is an Original NASA - CASSINI Spacecraft Radio-Image published on the NASA - Planetary Photojournal with the n. PIA 16197), since it is just a Radio-Image of the Titanian Surface and NOT a real view of it, has been colorized, according to an informed speculation carried out by Dr Paolo C. Fienga (LXTT-IPF), in what they could reasonably be its possible Absolute Natural Colors (such as the colors that a human eye would perceive if someone were onboard the NASA - CASSINI Spacecraft and, once the thick layer of Titanian Hazes and Fogs shall have been completely overcome, looked down, towards the Surface of Titan itself), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.MareKromium
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Titan-PIA10503.jpgLooking for Clouds... (IR - natural - but enhanced - colors; credits: Lunexit)90 visiteCaption NASA:"The Cassini Spacecraft peeks through the murk of Titan's thick atmosphere in a search for clouds. Although there are no obvious cloud features in this view, bright cloud streaks have occasionally been seen by Cassini and Earth-based telescopes in the region seen here toward the bottom of Titan's disk. Repeated monitoring observations like this one help scientists build an understanding of Titan's weather and the various climate processes operating on this frigid, but remarkably Earth-like moon.
This view looks toward the Saturn-facing Side of Titan (5150 kilometers, or 3200 miles across). North is up and rotated 35° to the left.
The image was taken with the Cassini Spacecraft narrow-angle camera on Sept. 25, 2008 using a spectral filter sensitive to wavelengths of Infrared Light centered at 938 nanometers. The view was acquired at a distance of approx. 1,7 MKM (such as about 1 MMs) from Titan.
Image scale is roughly 10 Km (approx. 6 miles) per pixel".MareKromium
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Titan-Lakes-Unnamed_North_Polar_Lakes-05-PIA08741.jpgTitanian Northern Lakes (5)88 visiteCaption NASA originale:"This lake is part of a larger image taken by the Cassini radar instrument during a flyby of Saturn's moon Titan on Sept. 23, 2006.
It shows clear shorelines that are reminiscent of terrestrial lakes. With Titan's colder temperatures and hydrocarbon-rich atmosphere, however, the lake likely contain a combination of methane and ethane, not water.
Centered near 74° North Latitude and 65° West Longitude, this lake is roughly 20 by 25 Km (about 12 to 16 miles) across. It features several narrow or angular bays, including a broad peninsula that on Earth would be evidence that the surrounding terrain is higher and confines the liquid. Broader bays, such as the one seen at right, might result when the terrain is gentler, as for example on a beach".
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Titan-PIA09858.jpgTitan approaches Saturn (natural colors; credits: NASA)85 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".MareKromium
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Titan-N00154035-47-EB-LXTT.jpgCosmic Smile (Natural Colors; credits for the additional process. and color.: Elisabetta Bonora - Lunexit Team)85 visiteElisabetta Bonora - al pari di Big "G" e Titanio 44 - fa Lavori eccezionali da tempo. Purtroppo, però, alla NASA questi Lavori non piacciono.
Forse perchè facciamo concorrenza ai loro "favoriti"; o forse perchè sono Lavori che dimostrano il possesso di conoscenze e capacità che non sono (più) una pertinenza esclusiva dei ragazzi di Pasadena... O forse perchè noi facciamo il nostro lavoro senza per questo essere dei "brown-nosers".
Quale che sia la verità, questo Lavoro è splendido e, a nostro parere, è pure (ed in Valore Assoluto) un Lavoro tecnicamente e scientificamente ineccepibile.
Se volessimo essere super-pignoli, allora potremmo suggerire che la luminosità della falce visibile di Titano è eccessiva e che quindi quanto si vede qui non è esattamente quello che vedremmo se ci trovassimo in loco. Ma queste sono minuzie...
Certo, qualche Fenomeno pronto a criticare tutto quello che facciamo lo troveremo sempre (soprattutto nel Bel Paese, dove tutti - specie gli anonimi detrattori - sono saggi, acculturati ed intelligenti...) ma questo è normale.
D'altronde, si sa e già lo dissero svariati Autori ed Attori, da Marziale a Vittorio Gassmann:"...coloro che non hanno la capacità di creare, criticano. E così fanno perchè, blaterando e scribacchiando nel tentativo di rendere misera la vita altrui, pensano e si illudono di alleviare e rendere sopportabile la loro stessa miseria...".MareKromium
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Titan-N00155017-21-44-EB-LXTT.jpgThrough the Clouds... (an Image-Mosaic by Elisabetta Bonora - Lunexit Team)85 visitenessun commentoMareKromium
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Titan-Senkyo_Region-PIA14655-PCF-LXTT-IPF.jpgSenkyo Region (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)85 visiteThe NASA - Cassini Spacecraft's "Electronic Eyes" peer through Titan's thick layers of Clouds to spy on the Region dubbed "Senkyo" by Planetary Scientists. Among the Dark Surface Features visible in this picture there is also a very vast Field of Dunes, possibly composed of solid Hydrocarbon Particles precipitated out of the Titanian Atmosphere; furthermore, the South Pole of Titan is, as you can see, still shrouded in the huge Vortex that formed only a few months ago (and whose origin is still debated). The lit Terrain seen here is located on the Saturn-facing Hemisphere of Titan; North is up and rotated 18° to the right.
This image was taken with the NASA - Cassini Spacecraft's Narrow-Angle Camera on January 5, 2013, by using a spectral filter sensitive to Wavelengths of Near-InfraRed Light centered at 938 Nanometers. The view was obtained at a distance of approximately 750.000 miles (such as a little more than 1,2 Million KiloMeters) from Titan and at a Sun-Titan-Cassini Spacecraft , or Phase, Angle of 79°. Image scale is roughly 4 miles (such as about 6,43 Km) per pixel.
This picture (which is an Original NASA - Cassini Spacecraft b/w frame published on the NASA - Planetary Photojournal and identified by the n. PIA 14655) has been additionally processed and then colorized, according to an educated guess carried out by Dr Paolo C. Fienga (LXTT-IPF), in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Cassini Spacecraft and then looked outside, towards the Saturnian moon Titan), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team. Different colors, as well as different shades of the same color, mean, among others, the existence of different Elements present in the Atmosphere of Titan, each having a different Albedo (---> Reflectivity) and Chemical Composition.
Note: it is possible (but we, as IPF, have no way to be one-hundred-percent sure of such a circumstance), that the actual luminosity of the Clouds and Hazes (as well as the luminosity of Titan itself) seen in this frame would appear, to an average human eye, way lower than it has been shown (or, better yet: interpreted) here.MareKromium
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Titan_and_Tethys-PIA12745.jpgBrothers in the Night84 visiteCaption NASA:"The Cassini Spacecraft watches a pair of Saturn's moons, showing the hazy orb of giant Titan beyond smaller Tethys.
In the foreground of the image, Ithaca Chasma can be seen running roughly North-South for more than 1000 Km (about 620 miles) on Tethys. Titan's detached, high-altitude Haze Layer and North Polar "Hood" are also visible here.
This view looks toward the Saturn-facing sides of Titan and Tethys.
The image was taken in Visible Green Light with the Cassini Spacecraft narrow-angle camera on Oct. 18, 2010. The view was obtained at a distance of approx. 2,5 MKM (such as about 1,6 MMs) from Titan and at a Sun-Titan-Spacecraft, or Phase, Angle of 55°. The view was obtained at a distance of approx. 1,5 MKM(such as about 930.000 miles) from Tethys and at a Sun-Tethys-Spacecraft, or Phase, Angle of 55°".MareKromium
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Titan-PIA10418.jpg"Banded" Planet83 visiteCaption NASA:"This Cassini Spacecraft view of Titan shows banding in the Atmosphere of the moon's Northern Hemisphere. Like the planet Venus, Titan's atmosphere rotates faster than its surface, a characteristic called "Super-Rotation."
North on Titan is up.
White specks seen on Titan are artifacts of the process used to enhance features in the moon's Atmosphere. The image was taken in visible blue light with the Cassini Spacecraft wide-angle camera on May 28, 2008. The view was obtained at a distance of approx. 185.000 Km (such as about 115000 miles) from Titan and at a Sun-Titan-Spacecraft, or Phase, angle of 89°.
Image scale is roughly 11 Km (about 7 miles) per pixel".MareKromium
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Titan-Regions-Senkyo_and_Aaru_Regions-PIA08231.jpgAaru and Senkyo82 visiteAs it approached Titan for yet another revealing encounter, the Cassini spacecraft acquired this image showing terrain on the moon's Saturn-facing hemisphere.
Prominent dark areas found in the moon's equatorial region appear to contain vast and continuous dune fields, discovered by the Cassini Radar experiment and likely composed of particles that drop from Titan's unique, smoggy atmosphere.
The Dark Regions seen here are provisionally named Aaru and Senkyo, with parts of Western Fensal and Aztlan showing at left, near the terminator.
The image was taken with the Cassini spacecraft wide-angle camera using a spectral filter sensitive to wavelengths of infrared light centered at 752 nanometers. The view was obtained on July 2, 2006 at a distance of approx. 163.000 Km (about 101.000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 62°.
Image scale is roughly 19 Km (such as about 12 miles) per pixel.
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