| Ultimi arrivi - Uranus and His Moons |
UMBRIEL.jpgFarewell Umbriel! (Natural Colors; credits: Ted Stryk)54 visitenessun commentoMareKromiumMar 09, 2009
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UMBRIEL-vg2-SV.jpgUmbriel's most prominent Surface Features: Skynd and Wunda Craters (Natural Colors; credits: NASA)54 visiteThe surface of Umbriel is an ancient one.
A collection of impact craters of various sizes was found to saturate the landscape. As Voyager 2 drew closer, became clear that most or all of the bright features are related to craters. On the Terminator, one can see 2 interesting craters.
One, Skynd, has a bright Central Peak. The other, Wunda, at the top of the image, has a bright rim and no apparent Central Peak. This is the best color image obtained by Voyager 2.MareKromiumMar 08, 2009
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UMBRIEL-vg2_p29502-Wunda.jpgUmbriel's extremely unusual surface feature: Wunda Crater (Natural Colors; credits: NASA)54 visiteHere is a closeup systhesis from all the close-ups of Wunda Crater.
It is hard to tell if the craters dug up the bright material, or if they had something to do with the impacts. Maybe it was derived from eruptions or melting caused by impacts.
Or maybe they are some sort of frost left over from impacts.
This issue may not be resolved until another spacecraft observes Umbriel. Here is the best view of Wunda that can be generated with the available data.MareKromiumMar 08, 2009
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Uranus-Neptune-HST3_.JPGUranus and Neptune, from HST (Natural Colors and Enhanced Natural Colors; credits: NASA)54 visitenessun commentoMareKromiumFeb 15, 2009
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UranusfromHST-1.JPGUranus, from HST (False Colors; credits: NASA)55 visitenessun commentoMareKromiumFeb 14, 2009
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UranusfromHST-2.JPGUranus, from HST (Natural, but enhanced, Colors; credits: NASA)66 visitenessun commentoMareKromiumFeb 14, 2009
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UranusfromHST-3.JPGUranus, from HST (Natural, but enhanced, Colors; credits: NASA)55 visitenessun commentoMareKromiumFeb 14, 2009
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UranusfromHST-4.JPGUranus, from HST (Natural, but enhanced, Colors; credits: NASA)56 visitenessun commentoMareKromiumFeb 14, 2009
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Miranda-B.JPGThe "Chevron Grooves" of Miranda (perspective view)54 visitenessun commentoMareKromiumFeb 14, 2009
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Miranda-A86-7026_a.jpgMiranda (possible natural colors; credits: Lunexit)55 visitenessun commentoMareKromiumNov 19, 2008
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VA-UranusRings-1.jpgUranus' Rings: yesterday, today, tomorrow54 visiteThe position of the Rings of Uranus from AD 1965 up to 2028.MareKromiumSet 16, 2007
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Uranus-2003.jpgGoing, Going, Gone: Hubble captures Uranus's Rings on Edge (1)55 visiteCaption NASA:"This series of images from NASA's HST shows how the Ring System around the distant planet Uranus appears at ever more oblique (shallower) tilts as viewed from Earth - culminating in the Rings being seen edge-on in 3 observing opportunities in 2007. The best of these events appears in the frame n. 3, taken with Hubble's Wide Field Planetary Camera 2 on August 14, 2007.
The "Edge-On Rings" appear as two spikes above and below the Planet. The Rings cannot be seen running fully across the face of the Planet because the bright glare of the planet has been blocked out in the Hubble photo (a small amount of residual glare appears as a fan-shaped image artifact). A much shorter color exposure of the Planet has been photo-composited to show its size and position relative to the Ring-Plane.
Earthbound astronomers only see Uranus Rings' edge every 42 years as the Planet follows a leisurely 84-year orbit about the Sun. However (and hironically), the last time the Rings were tilted Edge-On to Earth, astronomers didn't even know they existed".MareKromiumSet 16, 2007
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