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SaturnDustRing-SST.jpgDust-Ring around Saturn57 visiteWhat has created a large Dust-Ring around Saturn?
At over 200 times the radius of Saturn and over 50 times the radius of Saturn's expansive "E"-Ring, the newly discovered Dust-Ring is the largest planetary ring yet imaged. The Ring was found in IR Light by the Earth-orbiting Spitzer Space Telescope.
A leading hypothesis for its origin is impact material ejected from Saturn's moon Phoebe, which orbits right through the Dust-Ring's middle.
An additional possibility is that the Dust-Ring supplies the mysterious material that coats part of Saturn's moon Japetus, which orbits near the Dust-Ring's Inner Edge. Pictured above in the inset, part of the Dust-Ring appears as false-color orange in front of numerous background stars.MareKromium
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OPP-SOL1062-1P222466688EFF78DYP2664R1M1.jpgLate Afternoon on Mars - Sol 1062 (Natural Colors; credits: Lunexit)57 visitenessun commentoMareKromium
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The_Rings-PIA11600.jpgShadows on the Islands...57 visiteCaption NASA:"The shadows cast by Daphnis' attendant edge waves create a dark, jagged pattern on the A-Ring in this image taken as Saturn approached its August 2009 Equinox.
Daphnis (approx. 8 Km, or about 5 miles across) is a bright dot in the Keeler Gap of the A-Ring just below the center of the image. The moon has an inclined orbit, and its gravitational pull perturbs the orbits of the particles forming the Keeler Gap's edges and sculpts both edges into waves having both horizontal (radial) and out-of-plane components. Material on the inner edge of the gap orbits faster than the moon so that the waves there lead the moon in its orbit. Material on the outer edge moves slower than the moon, so waves there trail the moon. (See also PIA11656 to learn more about this process)
The novel illumination geometry that accompanies Equinox lowers the Sun's angle to the Ring-Plane, significantly darkens the Rings, and causes out-of-plane structures to look anomalously bright and cast shadows across the Rings. These scenes are possible only during the few months before and after Saturn's Equinox, which occurs only once in about 15 Earth years. Before and after Equinox, Cassini's cameras have spotted not only the predictable shadows of some of Saturn's moons (see also PIA11657), but also the shadows of newly revealed vertical structures in the Rings themselves (see, for example, the frame PIA11665).
This view looks toward the Northern, unilluminated side of the Rings, from about 36° above the Ring-Plane.
The image was taken in Visible Light with the Cassini Spacecraft narrow-angle camera on July 28, 2009. The view was obtained at a distance of approx. 1 MKM (about 621.000 miles) from Daphnis.
Image scale is roughly 6 Km (a little less than 4 miles) per pixel".MareKromium
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ZZ-Mercury-Terminator-PIA12279.jpgStrange Neighbors57 visiteThe MESSENGER Spacecraft was flying toward Mercury at 3,7 Km/second (8300 miles/hour) when it captured this image. The Sun was just above the horizon, and the deep shadows it cast emphasized the texture and topography of the terrain along the Terminator (day/night boundary). The large crater at upper left has a rough rim and walls, and the floor of this crater has a sunken inner circular area. At the center of the sunken floor section is an irregular depression (or pit) that is entirely in shadow in this view. Just to the South-South/West is the right half of another large crater whose rim intersects that of the crater with the sunken floor. The southern crater is about the same diameter as its northern neighbor, but instead of exhibiting a sunken floor with a pit, it has been filled nearly to its rim with smooth material likely of volcanic origin. These two close neighbors, one empty and one full, attest to the surprisingly complicated geological history of the little planet closest to the Sun.
Date Acquired: September 29, 2009
Image Mission Elapsed Time (MET): 162744138
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Resolution: 400 meters/pixel (0,25 miles/pixel)
Scale: This image is about 220 Km (approx. 140 miles) wide
Spacecraft Altitude: about 15.700 Km (approx. 9800 miles)MareKromium
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OPP-SOL2010-Nereus_Crater.jpgNereus Crater - Sol 2010 (Natural Colors; credits: Lunexit)57 visitenessun commentoMareKromium
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Tethys-PIA12319.jpgTethys and the Rings (Natural Colors; credits: NASA/JPL/Space Science Institute)57 visiteCaption NASA:"Cassini peers toward the distant, icy plains of Saturn's moon Tethys. The Planet's "A" and "F"-Rings slice across the top of this view.
This view of Tethys represents "Target 2" in the fall 2009 edition of the Cassini Scientist for a Day contest. (See http://saturn.jpl.nasa.gov/education/scientistforaday8thedition/.) The contest is designed to give students a taste of life as a scientist by challenging them to write an essay describing the value of one target choice among three for Cassini to image.
Images taken using red, blue and green spectral filters were combined to create this color view. The images were acquired with the Cassini wide-angle camera on Oct. 11, 2009 at a distance of approx. 1,4 MKM (about 900.000 miles) from Tethys".MareKromium
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OPP-SOL2032-GB.jpgShelter Island and Oppy's "Footprint" - Sol 2032 (Natural Colors; credits: Dr G. Barca)57 visitenessun commentoMareKromium
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ESP_014416_0950_RED_abrowse.jpgSouth Polar Layered Deposits (Natural Colors; credits: Lunexit)57 visitenessun commentoMareKromium
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OPP-SOL2031-GB~0.jpgNASA Logo and Surface - Sol 2031 (Natural Colors; credits: Dr G. Barca)57 visite...Siamo sempre in attesa di vedere che uno dei nostri Lavori venga pubblicato sulla prestigiosa Rubrica "NASA - Picture of the Day"...Ma forse, e nonostante tutto, è una speranza vana...MareKromium
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OPP-SOL2030-GB-LXT.jpgMartian Desolation... - Sol 2030 (Natural Colors; credits: Dr G. Barca & Lunexit)57 visitenessun commentoMareKromium
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ESP_014344_2195_RED_abrowse.jpgFeatures of Galaxias Fossae (Natural Colors; credits: Lunexit)57 visitenessun commentoMareKromium
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ESP_014380_1775_RED_abrowse-09.jpgExtremely Unusually-looking Skylight (EDM - Natural Colors - credits: Dr G. Barca & Lunexit)57 visitenessun commentoMareKromium
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