| Ultimi arrivi - Neptune and His Moons |
Triton-PIA02234.jpgTriton, from 530.000 Km!55 visiteCaption NASA:"Voyager 2 was 530.000 Km (330,000 miles) from Neptune's largest satellite, Triton, when this photo was taken, Aug. 24, 1989. With a resolution of 10 Km (about 6 miles), this is the first photo of Triton to reveal surface topography. The South Pole, continuously illuminated by sunlight at this season, is at bottom left. The boundary between the bright Southern Hemisphere and the darker Northern Hemisphere is clearly visible. Both the darker regions to the north and the very bright sub-equatorial band show a complex pattern of irregular topography that somewhat resembles "fretted terrain" on parts of Venus and Mars.
The pattern of dark and light Regions over most of the Southern Hemisphere will require HR images for interpretation. Also evident are long, straight lines that appear to be surface expressions of internal, tectonic processes. No large impact craters are visible, suggesting that the crust of Triton has been renewed relatively recently that is, within the past billion years or less".MareKromiumLug 23, 2007
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A_-_Neptune.jpgDo you see any difference?58 visiteAllora, che ne dite? I "true colors" di Nettuno secondo la NASA ed i "true colors" di Nettuno secondo Lunexit: vedete qualche (significativa) differenza?
Secondo noi non c'è (praticamente) alcuna differenza ed il motivo è semplice: Nettuno è lontano, freddo e dimenticato.
Nettuno non è una "minaccia" e non serve trasformarlo in qualcosa che non è. Marte, invece...Marte è vicino, terribilmente vicino e, forse, esistono almeno un milione di buoni motivi per "trasfigurarlo".
Forse.
O forse - come molti pensano - la NASA e l'ESA ci fanno vedere le cose per quello che sono (su Nettuno e su Marte ed ovunque nel Sistema Solare) e siamo noi a sbagliare, a fraintendere ed a trasfigurare...MareKromiumGen 02, 2007
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t Neptune Space.jpgNeptune's System55 visiteUn magnifico e realistico collage che ci mostra Nettuno e le sue Lune maggiori, insieme, per una "Foto Ricordo" di un viaggio indimenticabile...Set 28, 2006
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Triton-vg2_p34665.jpgTriton (in natural colors and HR)53 visitenessun commentoAgo 11, 2006
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Triton-vg2_1138639.jpgTriton (HR)53 visitenessun commentoAgo 11, 2006
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Nereid-vg2_1138148.jpgNereid (HR)54 visitenessun commentoAgo 11, 2006
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Proteus-vg2_1138920.jpgProteus (HR)54 visitenessun commentoAgo 10, 2006
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Neptune-PIA01998.jpgNeptune, from FAR away...54 visiteCaption NASA originale:"This image of Neptune was taken through the clear filter of the narrow-angle camera, when the Voyager 2 spacecraft was at a range of 57 MKM (about 35 MMs). The image was processed by computer to show the newly resolved dark oval feature embedded in the middle of the dusky southern collar. The large dark spot nearer the equator is also prominent on the left edge of the disk. The new small dark spot rotates faster than the large dark spot indicating that the winds on Neptune have different velocities at different latitudes as is the case for Jupiter, Saturn and Uranus".Lug 05, 2006
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Triton-PIA01994.jpgStrange "surface features" on Triton (clouds?!?)55 visiteCaption NASA originale"Already intriguing patterns of unknown origin appear on the surface of Neptune's largest satellite, Triton, in this image returned by Voyager 2. The image was taken Aug. 22, 1989, from a distance of about 4 MKM (approx. 2.5 MMs). Voyager images show that Triton's diameter is about 2.720 Km (approx. 1.690 miles) and that it is one of the brightest objects in the Solar System, reflecting about 70% of the sunlight that strikes it. This is the Hemisphere of Triton that always faces away from Neptune. The South Pole is near the bottom of the image. Triton's rotation axis is tilted so that the latitude at the center of the disk is 55° South. Dark regions at the top of the disk extend from roughly the equator to beyond 20° North. The margin between the bright and dark regions varies with longitude around the satellite. The gray, featureless area just to the right of the center of the disk is due to a reseau (reticule mark) in the camera".Lug 05, 2006
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ZA-U-Triton.jpgFarewell Triton... (HR)55 visitenessun commentoFeb 28, 2006
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Z-Thalassa.gifThalassa53 visiteThalassa appears to be about 80 Km (about 50 miles) in diameter.
It orbits Neptune in 7 hours and 30 minutes, about 25.200 Km (such as approx. 15.700 miles) above the cloud tops. It is irregularly shaped and shows no sign of any geological modification. Thalassa circles the Planet in the same direction as Neptune rotates. This image has been slightly smeared so that Thalassa appears highly elongated.Ott 28, 2005
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Triton-PEI.jpgMoments of Triton...56 visiteThis set of images shows the best views of Neptune's moon Triton taken by Voyager 2 as the spacecraft withdrew from the Neptune system on August 25, 1989. The top four images were constructed from various color image bands as Voyager receded from Triton.
The third image from the left is sharper than the other four, because it was taken with the Narrow Angle Camera, with Triton filling two thirds of the frame. The thin crescent first image, while much closer, spanned about a quarter of the frame. The second image was somewhat smaller, and the last was very small. The first of the four images was composed of Blue, Green, and Orange filter images. The second utilized Violet, Green, and Orange Filtered images. In both composites, the Orange image was of poorer quality. In the fourth image, no orange was available, and the green and blue images were badly smeared, though somewhat salvageable. A clear filtered image (also smeared) was substituted for orange. They were combined and used as a color overlay for a slightly overexposed, but sharp clear filtered view. The third image is composed of a Violet and a Green wide-angle image. Like all the images in the first and second composites, and like the images used to color the fourth composite, these images were underexposed. However, they were very sharp. The orange image came from a poor quality wide angle orange image. The resulting color image was combined with a well exposed clear filter image to provide the detail
The Narrow Angle images used in these mosaics were the first obtained after closest approach, with the exception of a single clear filter image obtained while the disk was about twice as big as what could be framed in the camera's field of view. It is very noisy, and by far the worst underexposure of them all, and could not be processed to the point in which the whole image could be made presentable. However, a few sections were salvaged. The first (lower left) was binned to make up for noisiness and sharpened. It was then merged with the color data from the third image above. A cloud can be seen near the limb. To its right is an image of the cloud that has not been as heavily processed. The cloud itself is better presented, as it was far brighter than the surrounding area and hence more securely detected. Its shadow can be faintly made out to its right.
The next two images are the same, but one to the right was merged with color data. The image is towards the center of the crescent, the brightest area, in which white spots can be seen. Although a few of them may be impact craters, this area, as most of the crescent, is over the south polar cap, and thus frost covered, and the appearance of this area most closely resembles the cantaloupe terrain seen on the other hemisphere before closest approach. The final image (lower right) hints of surface topography near the terminator. It seems it is one of the more rugged parts of Triton. The large, foreshortened circular feature slightly below the center of the image is a dimple similar those found in the cantaloupe terrain. The other features are too ambiguous to determine whether or not they are of the same nature.
Ott 28, 2005
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