| Piú votate - Uranus and His Moons |
VI-Puck-vg2_2683716.jpgPuck (HR)66 visitenessun commento
(6 voti)
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Miranda-vg2_2684617-B.jpgThe beautiful "Verona Rupes" from a different angle (detail mgnf)68 visiteUn detail mgnf dedicato ad un frame raro e stupendo che ci rammenta (ancora una volta) una delle Meraviglie del Sistema Solare: le Verona Rupes.
(6 voti)
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UT-Uranus Rings.jpgThe new "Giant Rings" of Uranus55 visiteEven though the Voyager 2 spacecraft paid a close-up visit to Uranus in 1986, the distant planet continues revealing surprises to the eye of NASA's HST. HST's high sensitivity and sharp view has uncovered a pair of Giant Rings girdling the Planet. The largest is twice the diameter of the Planet’s previously known Ring System, first discovered in the late 1970s. Hubble also spied two small satellites, named Mab and Cupid. One of the satellites shares an orbit with the outermost of the new Rings. The satellite is probably the source of fresh dust that keeps replenishing the ring with new material knocked off the satellite from meteoroid impacts. Without such replenishment, the dust in the ring would slowly spiral in toward Uranus. Collectively, these new discoveries mean that Uranus has a youthful and dynamic system of Rings and Moons (...) Uranus's Rings are mostly dust (...)".
(6 voti)
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VP-URANUS-PIA01360.jpgUranus in natural colors55 visiteCaption NASA originale"These 2 pictures of Uranus were compiled from images recorded by Voyager 2 on Jan. 1O, 1986, when the NASA spacecraft was 18 MKM (11 MMs) from the Planet. The images were obtained by Voyager 2 narrow-angle camera; the view is toward the planet's pole of rotation, which lies just left of center. The picture on the left has been processed to show Uranus as human eyes would see it from the vantage point of the spacecraft. The second picture is an exaggerated false-color view that reveals details not visible in the true-color view - including indications of what could be a polar haze of smog-like particles. The true-color picture was made by combining pictures taken through blue, green and orange filters. The dark shading of the upper right edge of the disk is the terminator, or day-night boundary. The blue-green appearance of Uranus results from methane in the atmosphere; this gas absorbs red wavelengths from the incoming sunlight, leaving the predominant bluish color seen here".
(6 voti)
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Miranda-PIA01354-PCF-LXTT.jpgVerona Rupes (Absolute Natural Colors; credits for the additional process. and color.: Dr Paolo C. Fienga - Lunexit Team)218 visitenessun commentoMareKromium
(5 voti)
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Titania-PIA01979.jpgTitania (possible Natural Colors; credits: Lunar Explorer Italia)56 visiteCaption NASA:"Voyager 2 obtained this full-disk view of Uranus' moon Titania in the early morning hours of Jan. 24, 1986, from a distance of about 500.000 Km (approx. 300.000 miles). Many circular depressions -- probably impact craters -- are visible in this clear-filter image returned by the Voyager narrow-angle camera.
Other bright spots are distinguished by radiating rays and are probably halo craters that mark relatively more recent impacts. Even more interesting are Linear Troughs (right) that are probably Fault Canyons (Tectonic Fractures). The Troughs break the crust in two directions, an indication of some tectonic extension of Titania's crust.
These features indicate that this icy satellite has a dynamic, active interior. Titania is about 1600 Km (approx. 1000 mi) in diameter; the resolution of this image is about 9 Km (approx. 6 mi) per pixel". MareKromium
(5 voti)
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Miranda-A86-7026_a.jpgMiranda (possible natural colors; credits: Lunexit)55 visitenessun commentoMareKromium
(5 voti)
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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".MareKromium
(5 voti)
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Uranus-2007-00.jpgGoing, Going, Gone: Hubble captures Uranus's Rings on Edge (3)54 visiteCaption NASA:"Showalter is a member of a team led by Imke de Pater of the University of California, Berkeley, who reported that the Rings of micron-sized dust have changed significantly since the Voyager 2 spacecraft photographed the Uranus System 21 years ago. Observations were also gleaned from near-infrared adaptive optics observations with the Keck II telescope on May 28, 2007, and reported in an article appearing on August 23 in Science Express, the online edition of Science Magazine".MareKromium
(5 voti)
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Uranus_and_Ariel.jpgUranus and Ariel: the Eclypse56 visiteCaption NASA originale:"This image is a never-before-seen astronomical alignment of a moon traversing the face of Uranus, and its accompanying shadow. The white dot near the center of Uranus' blue-green disk is the icy moon Ariel. The 700-mile-diameter satellite is casting a shadow onto the cloud tops of Uranus. To an observer on Uranus, this would appear as a solar eclipse, where the moon briefly blocks out the Sun as its shadow races across Uranus's cloud tops.
Though such "transits" by moons across the disks of their parents are commonplace for some other Gas Giant Planets, such as Jupiter, the satellites of Uranus orbit the planet in such a way that they rarely cast shadows on the Planet's Surface. Uranus is tilted so that its spin axis lies nearly in its orbital plane".
(5 voti)
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Titania-vg2_p29509.jpgTitania in natural colors (HR)55 visitenessun commento
(5 voti)
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Miranda-vg2_2684617-A.jpgThe beautiful "Verona Rupes" from a different angle (context image)62 visitenessun commento
(5 voti)
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