Saturn: the "Ringed Beauty" and His Moons
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Tethys.pngTethys and the Sun (possible Natural Colors; credits for the additional process. and color.: Marco Faccin and E. Bonora)105 visitenessun commentoMareKromium
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Epimetheus-PIA21335.jpgEpimetheus112 visitenessun commentoMareKromium
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Atlas.jpgAtlas (Credits: Dr Marco Faccin and Elisabetta Bonora)180 visitenessun commentoMareKromium
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Pandora.pngPandora: nice and close (Credits: Dr Marco Faccin and Elisabetta Bonora)135 visiteUnbelievable view.MareKromium
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Saturn-PIA21899.gifPolar Lights (Auroral Emissions from the North Pole of Saturn)111 visiteCaption NASA Originale:"On Sept. 14, 2017, one day before making its final plunge into Saturn's Atmosphere, NASA's Cassini Spacecraft used its Ultraviolet Imaging Spectrograph, or UVIS, instrument to capture this final view of Ultraviolet Auroral Emissions over the Planet's North Polar Regions.
The view is centered on the North Pole of Saturn, with lines of Latitude visible for 80, 70 and 60. Lines of Longitude are spaced 40 apart. The Planet's Day-Side is at the bottom of the picture, while the Night-Side is at the top. A sequence of images from this observation has also been assembled into a movie sequence. The last image in the movie was taken about an hour before the still image, which was the actual final UVIS auroral image.
Auroral Emissions are generated by charged particles traveling along the invisible lines of Saturn's Magnetic Field. These particles (then) precipitate into the Atmosphere, releasing light when they strike (the) Gas Molecules (that are present) there.
Several individual auroral structures are visible here, despite that this UVIS view was acquired at a fairly large distance from the Planet (such as about 424.000 miles or approx. 682.361,856 Km). Each of these features is connected to a particular phenomenon (occurring) in the Saturnian Magnetosphere. For instance, it is possible to identify Auroral "signatures" here that are related to the injection of "Hot Plasma" from the Day-Side Magnetosphere, as well as Auroral Features associated with a change in the Magnetic Field's shape (existing) on the Magnetosphere's Night-Side.
Several possible scenarios have been postulated over the years to explain Saturn's changing Auroral Emissions, but researchers are still far from a complete understanding of this complicated puzzle. Researchers will continue to analyze the hundreds of image sequences UVIS obtained of Saturn's auroras during Cassini's 13-year mission, with many new discoveries likely to be made.
This image and movie sequence were produced by the Laboratory for Planetary and Atmospheric Physics (LPAP) of the STAR Institute of the University of Liege in Belgium, in collaboration with the UVIS Team".MareKromium
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Atlas,_Daphins_and_Pan-PIA21449.jpgAtlas, Daphnis and Pan152 visiteCaption NASA:"This montage of views from NASA's Cassini Spacecraft shows three of Saturn's Small Ring moons: Atlas, Daphnis and Pan at the same scale for ease of comparison.
Two differences between Atlas and Pan are obvious in this montage. Pan's Equatorial Band is much thinner and more sharply defined, and the central mass of Atlas (the part underneath the smooth Equatorial Band) appears to be smaller than that of Pan.
All of these images were taken using the Cassini Spacecraft Narrow-Angle Camera. The images of Atlas were acquired on April 12, 2017, at a distance of about 10.000 miles (approx. 16,0093 Km) and at a Sun-moons-Spacecraft angle (or Phase Angle) of 37. All three images are oriented so that North is up".MareKromium
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Saturn-PIA21895.jpgFarewell Cassini...142 visiteCaption NASA:"This Natural Color view view is the last image taken by the imaging cameras on NASA's Cassini Spacecraft. It looks toward the planet's night side, lit by reflected light from the Rings, and shows the location at which the Spacecraft would enter the Planet's Atmosphere a few hours later.
ThE view was created by using images taken with red, green and blue spectral filters. The imaging cameras obtained the view at approximately the same time that Cassini's Vsual and InfraRed Mapping Spectrometer made its own observations of the impact area in the thermal infrared.
This location - the site of Cassini's atmospheric entry - was at this time on the night side of the Planet, but would rotate into daylight by the time Cassini made its final dive into Saturn's Upper Atmosphere, ending its remarkable 13-year exploration of Saturn.
The view was acquired on Sept. 14, 2017 at 19:59 UTC (spacecraft event time). The view was taken in Visible Light using the Cassini Spacecraft Wide-Angle Camera at a distance of about 394.000 miles (such as roughly 634.081 Km) from Saturn. Image scale is about 11 miles (about 17,7 Km). The original image has a size of 512 x 512 pixels".MareKromium
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Saturn-PIA21903-01.jpgThe End....113 visitenessun commentoMareKromium
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Saturn-PIA21903-00.jpgThe End....104 visiteCaption NASA originale:"This view of Saturn looks toward thePplanet's Night Side, only lit by Sunlight reflected from the Rings.
A mosaic of some of the very last images captured by Cassini's cameras, shows the location where the Spacecraft would have entered the Planet's Atmosphere a few hours later. An annotated view (see the next frame) marks the entry site with an oval. While this area was on the Night Side of the Planet at the time, it would rotate into daylight by the time Cassini made its final dive into Saturn's Upper Atmosphere, ending its remarkable 13-year exploration of Saturn.
Images taken using red, green and blue spectral filters were combined to show the scene in Near Natural Colors. The images were taken with Cassini's wide-angle camera on Sept. 14, 2017, at a distance of approx. 394.000 miles (such as a little more than 634.000 Km) from Saturn.
The Cassini spacecraft ended its mission on Sept. 15, 2017".MareKromium
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Tethys-PIA09915-1.jpgShall Odysseus ever find Ithaca? (Stretched Absolute Natural Colors; credits for the add. process.: Dr Paolo C. Fienga-LXTT-IPF)134 visiteCaption NASA:"From a highly inclined orbit, the Cassini Spacecraft looks toward far Northern Latitudes on Tethys.
Here, the spacecraft was above a position about 45 North of the moon's Equator.
This vantage point afforded a view of the moon's three most recognizable features: the Ithaca Chasma Canyon System (at lower right), Odysseus Crater (at upper left) and the Equatorial Band of Darker Terrain (at lower left).
Lit terrain seen here is on the Leading Hemisphere of Tethys (1062 Km, or approx. 660 miles across). North is up.
The image was taken in Visible Light with the NASA - Cassini Spacecraft narrow-angle camera on April 29, 2008.
The view was obtained at a distance of approx. 991.000 Km (such as about 616.000 miles) from Tethys and at Phase Angle of 73.
Image scale is roughly 6 Km (about 4 miles) per pixel".MareKromium
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Enceladus-PIA18328-PCF-LXTT-IPF.jpgIn the Saturnshine... (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga/Lunar Explorer Italia/Italian Planetary Foundation)124 visiteThe Saturnian moon Enceladus looks as if it is half lit by Sunlight in this view from the NASA - Cassini Spacecraft; but looks, as you know, can be (as they often are) deceiving.
In fact, the kind of pinkish area of Enceladus visible on the right (Dx) of the frame, where MANY Surface Features can be made out (---> seen/identified), is actually illuminated by the light reflected off of Saturn (such as the so-called "Saturnshine"). On the other hand, a sliver of the Enceladian Surface that is actually illuminated by direct Sunlight is visible - and also highly overexposed! - on the left (Sx) of the picture. Images like this one are designed to capture the extended Plumes of Icy Materials spraying from huge cracks located the moon's South Polar Region. Such images need to be taken with the NASA - Cassini Spacecraft looking toward the Icy moon's Night Side, since the small particles that form the Plumes (however, just barely visible in this picture) are most easily seen when backlit by the Sun.
This view looks toward the Leading Hemisphere of Enceladus; North is up. The image was taken in Visible Light with the NASA - Cassini Spacecraft's Narrow-Angle Camera on May 10, 2015. Enceladus is roughly 313 miles (such as about 503,72 Km) across. The view was acquired at a distance of approximately 226.000 miles (such as approx. 363.7210,84 Km) from Enceladus and at a Sun-Enceladus-Cassini Spacecraft, or Phase, Angle of 152. Image scale is roughly 1,4 miles (about 2,2530 Km) per pixel.
This frame (which is an Original NASA - CASSINI Spacecraft's b/w and NON Map-Projected image published on the NASA - Planetary Photojournal with the ID n. PIA 18328) has been additionally processed, contrast enhanced, magnified, in order to allow the vision of the slightest details of the Surface, Gamma corrected and then re-colorized - according to an educated guess (or, if you wish, an informed speculation) carried out by Dr Paolo C. Fienga - 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, toward the Saturnian moon "Enceladus"), 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 other things, the existence of different Elements (Minerals) present on the Surface of Enceladus, 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 Enceladus - as it is in this frame - would appear, to an average human eye, a little bit lower than it has been shown (or, better yet: interpreted) here.MareKromium
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