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| Ultimi arrivi - Jupiter: the "King" and His Moons |
Ganymede-lor_0035286119_0x630_sci_1.jpgThe "obscure outline" of Ganymede (1)57 visiteDescription: Ganymede crossing crescent Jupiter
Time: 2007-03-04 03:50:01 UTC
Exposure: 2 msec
Target: GANYMEDE
Range: 5,9 MKMMareKromiumGiu 01, 2007
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Ganymede-lor_0035286134_0x630_sci_1.jpgThe "obscure outline" of Ganymede (2)54 visiteDescription: Ganymede crossing crescent Jupiter
Time: 2007-03-04 03:50:16 UTC
Exposure: 80 msec
Target: GANYMEDE
Range: 5,9 MKM MareKromiumGiu 01, 2007
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Io-lor_0035102969_0x630_sci_1.jpgMoments of Tvashtar (1)78 visitenessun commentoMareKromiumMag 23, 2007
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Io-lor_0035116949_0x630_sci_1.jpgMoments of Tvashtar (2)93 visitenessun commentoMareKromiumMag 23, 2007
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Io-lor_0035222842_0x630_sci_2.jpgMoments of Tvashtar (3)70 visitenessun commentoMareKromiumMag 23, 2007
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Io-051407_loop.gifErupting Tvashtar (GIF Movie)58 visiteThis five-frame sequence of New Horizons images captures the giant plume from Io's Tvashtar volcano. Snapped by the probe’s Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Jupiter earlier this year, this first-ever “movie” of an Io plume clearly shows motion in the cloud of volcanic debris, which extends 330 Km (200 miles) above the moon’s surface. Only the upper part of the plume is visible from this vantage point – the plume’s source is 130 Km (about 80 miles) below the edge of Io's disk, on the far side of the moon.
The appearance and motion of the plume is remarkably similar to an ornamental fountain on Earth, replicated on a gigantic scale. The knots and filaments that allow us to track the plume’s motion are still mysterious, but this movie is likely to help scientists understand their origin, as well as provide unique information on the plume dynamics.
Io's hyperactive nature is emphasized by the fact that two other volcanic plumes are also visible off the edge of Io's disk: Masubi at the 7 o'clock position, and a very faint plume, possibly from the volcano Zal, at the 10 o'clock position.
Jupiter illuminates the night side of Io, and the most prominent feature visible on the disk is the dark horseshoe shape of the volcano Loki, likely an enormous lava lake. Boosaule Mons, which at 18 Km (about 11 miles) is the highest mountain on Io and one of the highest mountains in the Solar System, pokes above the edge of the disk on the right side.
The five images were obtained over an 8-minute span, with two minutes between frames, from 23:50 to 23:58 Universal Time (UT) on March 1, 2007. Io was approx. 3,8 MKM (about 2,4 MMs) from New Horizons; the image is centered at Io coordinates 0° North Lat. and 342° West Long.
The pictures were part of a sequence designed to look at Jupiter's Rings, but planners included Io in the sequence because the moon was passing behind Jupiter's Rings at the time.MareKromiumMag 16, 2007
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Io-050107_08~0.jpgThe "Burning Night" of Io - possible natural colors (elab. Lunexit)56 visitenessun commentoMareKromiumMag 02, 2007
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Europa-050107_01.jpgRising Europa55 visiteNew Horizons took this image of the icy moon Europa rising above Jupiter’s cloud tops with its Long Range Reconnaissance Imager (LORRI) at 11:48 Universal Time on February 28, 2007, six hours after the spacecraft’s closest approach to Jupiter.
The picture was one of a handful of the Jupiter System that New Horizons took primarily for artistic, rather than scientific, value. This particular scene was suggested by space enthusiast Richard Hendricks of Austin, Texas, in response to an Internet request by New Horizons scientists for evocative, artistic imaging opportunities at Jupiter.
The spacecraft was 2,3 MKM (about 1,4 MMs) from Jupiter and 3 MKM (such as about 1,8 MMs) from Europa when the picture was taken.
Europa's diameter is 3.120 kilometers (1.939 miles).
The image is centered on Europa coordinates 5° South and 6° West.
In keeping with its artistic intent - and to provide a more dramatic perspective - the image has been rotated so South is at the top.
Nota: in data 9 Maggio 2007, la NASA pubblica nel suo "Planetary Photojournal" questa medesima immagine con il medesimo titolo.
Se non altro, dato che sappiamo che la NASA legge Lunexit, ci farebbe piacere ricevere, di quando in quando, un "grazie per la collaborazione!"...MareKromiumMag 02, 2007
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Jupiter-050107_11.jpgThe "Little Spot" of Jupiter56 visiteThis amazing color portrait of Jupiter’s “Little Red Spot” (LRS) combines high-resolution images from the New Horizons Long Range Reconnaissance Imager (LORRI), taken at 03:12 UT on February 27, 2007, with color images taken nearly simultaneously by the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope. The LORRI images provide details as fine as 9 miles across (15 Km), which is approx. 10 times better than Hubble can provide on its own.
The improved resolution is possible because New Horizons was only 1,9 MMs (about 3 MKM) away from Jupiter when LORRI snapped its pictures, while Hubble was more than 500 MMs (abou 800 MKM) away from the Gas Giant Planet.
The Little Red Spot is the second largest storm on Jupiter, roughly 70% the size of the Earth, and it started turning red in late-2005. The clouds in the Little Red Spot rotate counterclockwise, or in the anticyclonic direction, because it is a high-pressure region. In that sense, the Little Red Spot is the opposite of a hurricane on Earth, which is a low-pressure region – and, of course, the Little Red Spot is far larger than any hurricane on Earth.
Scientists don't know exactly how or why the Little Red Spot turned red, though they speculate that the change could stem from a surge of exotic compounds from deep within Jupiter, caused by an intensification of the storm system. In particular, sulfur-bearing cloud droplets might have been propelled about 50 kilometers into the upper level of ammonia clouds, where brighter sunlight bathing the cloud tops released the red-hued sulfur embedded in the droplets, causing the storm to turn red. A similar mechanism has been proposed for the Little Red Spot's "older brother," the Great Red Spot, a massive energetic storm system that has persisted for over a century.
New Horizons is providing an opportunity to examine an “infant” red storm system in detail, which may help scientists understand better how these giant weather patterns form and evolve.
MareKromiumMag 02, 2007
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Io-050107_03.jpgTvashtar's Rainbow...55 visiteVariations in the appearance of the giant plume from the Tvashtar volcano on Jupiter's moon Io are seen in this composite of the best photos taken by the New Horizons Long Range Reconnaissance Imager (LORRI) during its Jupiter flyby in late February-early March 2007.
New Horizons was fortunate to witness this unusually large plume during its brief Jupiter flyby; the Galileo Jupiter orbiter spent more than five years imaging the volcanic moon (between 1996 and 2001) without ever capturing such detailed pictures of a large Io plume. The plume is roughly 330 Km (about 200 miles) high. The cause of the fine wispy structure in the plume, which varies strikingly from image to image, is unknown, but these pictures may help scientists to understand the phenomenon.
The pictures were taken at distances ranging from 3,1 to 2,3 MKM (such as from 1,9 to 1,4 MMs), but they have been scaled to show the plume at the same relative size in every frame. Illumination conditions also vary: in the final image, Io's shadow cuts across the plume and hides all but its topmost regions, and the glow of hot lava can be seen on the nightside at the source of the plume.
The times of the images, from top to bottom, are: February 26, 18:38 (Universal Time); February 26, 21:01; February 28, 03:50; February 28, 04:40; February 28, 11:04 and March 1, 00:35.MareKromiumMag 02, 2007
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Io-050107_04.jpgPlanetary Flares57 visiteThis montage demonstrates New Horizons' ability to observe the same target in complementary ways using its diverse suite of instruments. Previously released views taken at visible and slightly longer infrared wavelengths with the Long Range Reconnaissance Imager (LORRI), New Horizons’ high-resolution black-and-white camera, and the Multispectral Visible Imaging Camera (MVIC), its color camera, are here compared with a nearly simultaneous view from the Linear Etalon Imaging Spectral Array (LEISA), which observes its targets in more than 200 separate wavelengths of infrared light. This color LEISA view of Io (bottom right) combines three wavelength ranges, centered at 1.80, 2.04, and 2.31 micrometers.
The LORRI image (left) shows fine details on Io's sunlit crescent and in the partially sunlit plume from the Tvashtar volcano, and reveals the bright nighttime glow of the hot lavas at the source of the Tvashtar plume. The MVIC image (top right) shows the contrasting colors of the red lava and blue plume at Tvashtar, and the sulfur and sulfur dioxide deposits on Io's sunlit surface. The LEISA image shows that the glow of the Tvashtar volcano is even more intense at infrared wavelengths and reveals the infrared glow of at least 10 fainter volcanic hot spots on the moon’s nightside. The brightest of these, Amirani/Maui, which is visible to the lower right of Tvashtar, is less than 4% as bright as Tvashtar. All of these are long-lived hot spots that have been observed previously by the Galileo orbiter. Further analysis of the LEISA data will provide information on the volcanoes’ temperatures, and data on the sunlit crescent of Io will reveal details of Io's surface composition.
The LORRI, MVIC and LEISA images were taken March 1, 2007, at 00:35, 00:25 and 00:31 Universal Time, respectively, from a range of 2,3 MKM (about 1,4 MMs).
The images are centered at Io coordinates 4° South and 164° West.MareKromiumMag 02, 2007
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Io-050107_07.jpgAs Time goes by...On Io!54 visiteThis montage compares similar sides of Io photographed by the Galileo spacecraft in October 1999 and the New Horizons spacecraft on February 27, 2007.
The New Horizons image was taken with its Long Range Reconnaissance Imager (LORRI) from a range of 2,7 MKM (about 1,7 MMs).
Most features on Io have changed little in the 7-plus years between these images, despite continued intense volcanic activity. The largest visible feature is the dark oval composed of deposits from the Pele Volcano, nearly 1200 Km (about 750 miles) across its longest dimension. At high Northern Latitudes, the volcano Dazhbog is prominent as a dark spot in the New Horizons image, near the edge of the disk at the 11 o'clock position. This volcano is much less conspicuous in the Galileo image. This darkening happened after this 1999 Galileo image but before Galileo took its last images of Io in 2001.
A more recent change, discovered by New Horizons, can be seen in the Southern Hemisphere (circled).
A new volcanic eruption - near 55° South and 290° West - has created a roughly circular deposit nearly 500 Km (about 300 miles) in diameter that was not seen by Galileo. Other New Horizons images show that the plume that created this deposit is still active.
The New Horizons image is centered at Io coordinates 8° South and 269° West.
MareKromiumMag 02, 2007
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