| Piú votate - Titan: The "Foggy" Moon |
Titan-Cryovolcanism_Map-PIA11702.jpgActive Cryovolcanism on Titan?56 visiteCaption NASA:"The Cassini Radar Mapper imaged Titan on Feb. 22, 2008 (as shown on the left) and April 30, 2006 (as shown on the right).
These radar images show the outlines of Regions "1" and "2" identified by Cassini's VIMS (such as the Visual and Infrared Mapping Spectrometer) and inferred to be variable (see VIMS flat map, PIA11701), and which have been hypothesized to be due to cryovolcanic activity. The lobate, flow-like features in Region 1 are consistent with this interpretation.
Region 1 is just north of the feature named Hotei Arcus and is centered on 28° South Lat. by 78° West Long.
The Region is about 400 Km (approx. 249 miles) across. Region 2 is on the western part of Xanadu and is centered on 7° South Lat. by 135° West Long. This region is about 900 Km (approx. 560 miles) across. In both cases, North is up, and features as small as 300-500 meters can be resolved".MareKromium
(2 voti)
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Titan-PIA10418.jpg"Banded" Planet84 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
(2 voti)
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Titan-PIA10243.jpgUnder the Fog...104 visiteCaption NASA:"This graphic depicts a cross-section of the Saturnian moon Titan. Cassini scientists speculate there may be a layer of liquid water mixed with ammonia about 100 Km (approx. 62 miles) below the surface of Titan.
The assumption that Titan contains an internal ocean was generated from data gleaned from Cassini's Synthetic Aperture Radar during 19 separate passes over Titan between October 2005 and May 2007. Using data from the radar’s early observations, the scientists and radar engineers established the locations of 50 unique landmarks on Titan's surface. They then searched for these same lakes, canyons and mountains in the reams of data returned by Cassini in its later flybys of Titan. What they found was prominent surface features seemed to shift from their expected positions by up to 31 Km (about 19 miles). Since the features could not have really moved, the apparent shift told the scientists and engineers that Titan was spinning about its axis in a previously unsuspected manner. The pre-Cassini model of Titan's spin accounted for the gravitational fields of Saturn and other nearby planets and moons but omitted other smaller less well understood effects. Since the observed spin of Titan does not fit this model, other influences, such as the seasonal changes in the motion of its atmosphere must also be important. It is difficult to explain how such relatively low energy phenomena could have such a pronounced influence on Titan's spin unless the moon's icy crust was decoupled from its core by an internal ocean. If the crust were decoupled from the core, atmospheric fluctuation alone could account the observed spin".MareKromium
(2 voti)
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Titan-Huygens_Landing_Site-02-LS28_PSS_LASoderblom_VIMSRADAR20070323.jpgHuygens Probe Landing Site57 visiteThese images of the Huygens Landing Site on Titan were obtained by Cassini’s SAR radar (1st and 3rd rows) and VIMS (2nd and 4th rows) instruments, and are correlated in this composite view.
The 4 upper images show the Region of the Sinlap Crater in the Huygens Landing Site Region. The area shown is about 850 by 1150 Km wide.
The 4 lower images are colour-mapped as: red, to indicated solid dunes; yellow, to indicate a partial dune coverage; and green to indicate not mappable areas.MareKromium
(2 voti)
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Titan-Dunes-PIA08738.jpgLongitudinal Dunes?56 visiteCaption NASA originale:"This image from Cassini's radar instrument was acquired by the Cassini radar instrument in synthetic aperture mode during a Sept. 7, 2006, flyby of Titan. The image shows long, dark ridges similar to those seen in previous flybys. These are interpreted to be "Longitudinal Dunes". Dunes are mostly an equatorial phenomenon on Titan and the material forming them may be solid organic particles or ice coated with organic material. Spaced up to 3 Km(about 2 miles) apart, these dunes curve around bright features that may be high-standing topographic obstacles, in conformity with the wind patterns.
The interaction between the 2 types of features is complex and not well understood, but clearly the topography and the dunes have influenced each other in other ways as well.
This image is centered at 44° West Long., 8° North Lat. and covers approx. 160 by 325 Km (such as about 99 by 202 miles) on Titan's surface. The smallest details in this image are about 500 mt (approx. 550 yards) across".
(2 voti)
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Titan-N00055569.jpgWhat's happening on Titan? (6)59 visiteCaption NASA:"N00055569.jpg was taken on March 20, 2006 and received on Earth March 20, 2006. The camera was pointing toward Titan that, at the time, was approximately 974.790 Km away.
The image was taken using the P120 and BL2 filters".
(2 voti)
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Titan-Huygens_Landing_Site-09-PIA06172_modest.jpgHuygens' descent map (1)57 visiteCaption NASA originale:"This map illustrates the planned imaging coverage for the Descent Imager/Spectral Radiometer (DISR), onboard the Huygens probe during the probe's descent toward Titan's surface on Jan. 14, 2005. The DISR is one of two NASA instruments on the probe. The colored lines delineate regions that will be imaged at different resolutions as the probe descends. On each map, the site where Huygens is predicted to land is marked with a yellow dot. This area is in a boundary between dark and bright regions. This map was made from the images taken by the Cassini spacecraft cameras on Oct. 26, 2004, at image scales of 4 to 6 Km per pixel. The images were obtained using a narrow band filter centered at 938 nanometers - a near-infrared wavelength (invisible to the human eye) at which light can penetrate Titan's atmosphere to reach the surface and return through the atmosphere to be detected by the camera. The images have been processed to enhance surface details".
(2 voti)
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Titan-Huygens_Landing_Site-08-PIA06136_modest.jpgHuygens' probe landing site56 visiteCaption originale NASA (dal "Planetary Photojournal"):"Shown here are two images of the expected landing site of Cassini's Huygen's probe (latitude 10.6 S, longitude 191 W). At right is a wide-angle image showing most of Titan's disc, with a scale of 10 Km (6.2 miles) per pixel. At left is a narrow-angle image of the landing site at a scale of 0.83 Km (0.5 miles) per pixel (location shown by black box at right). North is tilted about 45 degrees from the top of both images. The surface has bright and dark markings with a streamlined pattern consistent with motion from a fluid, such as the atmosphere, moving from west to east (upper left to lower right). The image at left is 400 Km (249 miles) wide. Both images were taken by Cassini's imaging science subsystem through near-infrared filters".
(2 voti)
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Titan-Close Up 7.jpgTitan's fly-by "A" - Close-up 7 (the "limb" of Titan)55 visitenessun commento
(2 voti)
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Titan-Clouds-White_Clouds-Mosaic.jpgTitan from about 340.000 Km60 visiteCaption originale da "NASA - Picture of the Day" del 26 Ottobre 2004:"What are these surface features on Titan? This planet-sized moon of Saturn had much of its south polar surface imaged during an initial flyby by the Saturn-orbiting Cassini spacecraft back in early July. The above image mosaic was digitally stitched together from pictures taken at a very specific color of polarized infrared light, a color not absorbed and little scattered by Titan's methane haze. Visible are light and dark regions that are not yet understood. Surface features as small as 10 Km are resolved from about 340.000 Km away. The white region near Titan's South Pole, left of center, is unusually thick clouds also thought to be composed of methane. Today Cassini will swoop to within 1,500 kilometers above Titan and may return data and images that help humanity better understand this strange world".
(2 voti)
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Titan-PIA22481-1.jpgThe Great Seas and Lakes of Titan175 visiteCaption NASA:"During NASA's Cassini mission's final distant encounter with Saturn's giant moon Titan, the Spacecraft captured this view of the truly enigmatic moon's North Polar landscape of Lakes and Seas, which are filled with liquid Methane and Ethane.
Punga Mare (about 240 miles, or approx. 386,2 Km, across) is seen just above the center of the mosaic, with Ligeia Mare (roughly 300 miles, or about 48,3 Km, wide) below center and vast Kraken Mare stretching off 730 miles (such as approx. 1.174,8 Km) to the left of the mosaic. Titan's numerous smaller and still Unnamed Lakes can be seen around the seas and scattered around the right side of the mosaic. Among the ongoing mysteries about Titan is how these Seas and Lakes are formed.
Another mystery at Titan has been the weather. With its extremely dense Atmosphere, Titan has a Methane Cycle much like Earth's Water Cycle of evaporation, cloud formation, rainfall, surface runoff into Rivers, and collection in Lakes and Seas.
During Titan's Southern Summer, the Cassini Spacecraft also observed Cloud activity over the South Pole.
However, typical of observations taken during Northern Spring and Summer, the view here reveals only a few small clouds. They appear as bright features just below the center of the mosaic, including a few above Ligeia Mare.
The images in this mosaic were taken with the ISS Narrow-Angle Camera, using a spectral filter sensitive to wavelengths of Near-InfraRed Light centered at 938 nanometers.
They were captured on Sept. 11, 2017, during Cassini's last encounter with Titan. Four days later, Cassini was deliberately plunged into the Atmosphere of Saturn.
The view was obtained at a distance of approximately 87.000 miles (a little less than 140,013 Km) from Titan. Image scale is about 0,5 miles (approx. 800 meters) per pixel.
The image is an Orthographic Projection centered on 67,19° North Latitude and 212,67° West Longitude.
Note: an Orthographic View is most like the view seen by a distant observer looking through a telescope".MareKromium
(1 voti)
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Titan_and_Tethys-PIA14911.jpgTitan and Tethys (Natural Colors; credits: NASA/JPL-Caltech/Space Science Institute)100 visiteCaption NASA:"Saturn's moon Tethys, with its stark white Icy Surface, peeps out from behind the larger, hazy, colorful Titan in this view of the two moons obtained by NASA's Cassini Spacecraft. Saturn's Rings lie between the two Celestial Bodies.
Ithaca Chasma, a long series of Scarps or Cliffs on Tethys, can be seen faintly running North-South.
This view looks toward the side of Titan that is facing away from Saturn and the side of Tethys that is facing Saturn. This view looks toward the Northern, sunlit side of the Rings from just above the Ring-Plane. 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 May 21, 2011, at a distance of approx. 1,4 MMs (about 2,3 MKM) from Titan and approx. 2,4 MMs (such as about 3,8 MKM) from Tethys. Image scale is roughly 9 miles (approx. 14 Km) per pixel on Titan and roughly 18 miles (approx. 27 Km) per pixel on Tethys".MareKromium
(1 voti)
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