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Jupiter: the "King" and His Moons |
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Europa's terminator23 visteThis image of Europa was obtained by the Solid State Imaging (CCD) System on board NASA's Galileo spacecraft during its 4th orbit of Jupiter. Linear features with bright central stripes referred to as "Triple Bands" (TB) are seen to transect the surface of Europa. Several of these TBs are over 700 Km in length. In the left side of the image the surface of Europa is seen to be locally pitted and irregular. Ridges less than 100 Km in length are also visible in this Region.
The area seen in this image, centered near 27° South and 300° West, is 760 (456 miles) by 850 Km (510 miles) across, which is approximately the size of the state of Texas or the country of France. North is to the top of the image, with the sun illuminating the surface from the left. The image which has a resolution of 1,3 Km per picture element (e cioč "per pixel") was obtained on December, 19th, 1996.
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Europa: a splendid frame (in Super HD)26 visteDark crisscrossing bands on Jupiter's moon Europa represent widespread disruption from fracturing and the possible eruption of gases and rocky material from the moon's interior in this four-frame mosaic of images from NASA's Galileo spacecraft. These and other features suggest that soft ice or liquid water was present below the ice crust at the time of disruption. The data do not rule out the possibility that such conditions exist on Europa today. The pictures were taken from a distance of 156,000 kilometers (about 96,300 miles) on June 27, 1996. Many of the dark bands are more than 1,600 kilometers (1,000 miles) long, exceeding the length of the San Andreas fault of California. Some of the features seen on the mosaic resulted from meteoritic impact, including a 30- kilometer (18.5 mile) diameter crater visible as a bright scar in the lower third of the picture. In addition, dozens of shallow craters seen in some terrains along the sunset terminator zone (upper right shadowed area of the image) are probably impact craters. Other areas along the terminator lack craters, indicating relatively youthful surfaces, suggestive of recent eruptions of icy slush from the interior. The lower quarter of the mosaic includes highly fractured terrain where the icy crust has been broken into slabs as large as 30 kilometers (18.5 miles) across. The mosaic covers a large part of the northern hemisphere and includes the north pole at the top of the image. The sun illuminates the surface from the left. The area shown is centered on 20 degrees north latitude and 220 degrees west longitude and is about as wide as the United States west of the Mississippi River.
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Different surface features of Europa30 viste1. Triple bands and dark spots were the focus of some images from Galileo's eleventh orbit of Jupiter. Triple bands are multiple ridges with dark deposits along the outer margins. Some extend for thousands of kilometers across Europa's icy surface. They are cracks in the ice sheet and indicate the great stresses imposed on Europa by tides raised by Jupiter, as well as Europa's neighboring moons, Ganymede and Io. The dark spots or "lenticulae" are spots of localized disruption.
2. The Conamara Chaos region reveals icy plates which have broken up, moved, and rafted into new positions. This terrain suggests that liquid water or ductile ice was present near the surface. On Galileo's twelfth orbit of Jupiter, sections of this region with resolutions as high as 10 meters per picture element will be obtained.
3. Mannann'an Crater is a feature newly discovered by Galileo in June 1996. Color and high resolution images (to 40 meters per picture element) from Galileo's fourteenth orbit of Jupiter will offer a close look at the crater and help characterize how impacts affect the icy surface of this moon.
4. Cilix, a large mound about 1.5 kilometers high, is the center of Europa's coordinate system. Its concave top and what may be flow like features to the southwest of the mound are especially intriguing. The origin of this feature is unknown at present. Color, stereo, and high resolution images (to 65 meters per picture element) from Galileo's fifteenth orbit of Jupiter will offer new insights and resolve questions about its origin.
5. Images of Agenor Linea (white arrow) and Thrace Macula (black arrow) with resolutions as high as 30 meters per picture element will be obtained during Galileo's sixteenth orbit of Jupiter. Agenor is an unusually bright lineament on Europa. Is the brightness due to new ice, and if so, does it represent recent activity? Could the dark region of Thrace Macula be a flow from ice volcanism?
6. Images of Europa's south polar terrain obtained during Galileo's seventeenth orbit of Jupiter will offer insights into the processes which are active in this region. Is the ice crust thicker near Europa's poles than near the equator? The prominent dark line running from upper left to lower right through the center of this image is Astypalaea Linea. It is a fault about the length of the San Andreas fault in California and is the largest such fault known on Europa. Images with resolutions of 48 meters per picture element will be obtained to examine its geologic structure.
7. This long lineament, Rhadamanthys Linea. is spotted with dark "freckles". Are these freckle features formed by icy volcanism? Is this an early form of a triple band? Stereo and high resolution (to 46 meters per picture element) obtained during Galileo's eighteenth orbit of Jupiter may indicate whether the lineament is the result of volcanic processes or is formed by other surface processes.
8. During Galileo's nineteenth orbit of Jupiter, images of Europa will be taken with very low sun illuminations, similar to taking a picture at sunset or sunrise. The object will be to search for backlit plumes issuing from icy volcanic vents. Such plumes would be direct evidence of a liquid ocean beneath the ice. Resolutions will be as high as 40 meters per picture element. This picture was simulated image from Galileo data obtained during the spacecraft's second orbit of Jupiter in September 1996.
North is to the top of the pictures. During orbit 13, the Galileo spacecraft was behind the sun from our vantage point on Earth so it did not obtain or transmit data from that orbit. The left two images in the bottom row were obtained by NASA's Voyager 2 spacecraft in 1979; the remaining images were obtained by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft in 1996.
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Conamara Chaos Region (HR)31 visteThis HR view of the Conamara Chaos Region on Jupiter's moon Europa, reveals craters which range in size from about 30 to over 450 mt (slightly over 1/4 of a mile) in diameter. The large number of craters seen here is unusual for Europa. This section of Conamara Chaos lies inside a bright ray of material which was ejected by the large impact crater, Pwyll, about 1000 Km (620 miles) to the South. The presence of craters within the bright ray suggests that many are secondaries which formed from chunks of material that were thrown out by the enormous energy of the impact which formed Pwyll. North is to the upper right of the picture and the Sun illuminates the surface from the East. The image, centered at 9° Latitude and 274° Longitude, covers an area of approx. 8 by 4 Km (such as about 5 by 2,5 miles). The finest details that can be discerned in this picture are about 20 mt (66 feet) across. The images were taken on December 16, 1997 from a distance of 960 Km from Europa.
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Dark Region on Europa26 visteThis view taken by NASA's Galileo spacecraft of Jupiter's icy moon Europa focuses on a dark, smooth Region whose center is the lowest area in this image. To the West (left), it is bounded by a cliff and terraces, which might have been formed by normal faulting. The slopes toward the East (right) leading into the dark spot are gentle. Near the center of the dark area, it appears the dark materials have covered some of the bright terrain and ridges. This suggests that when the dark material was deposited, it may have been a fluid or an icy slush. Only a few impact craters are visible, with some of them covered or flooded by dark material. Some appear in groups, which may indicate that they are secondary craters formed by debris excavated during a larger impact event. A potential source for these is the nearby crater Mannann`an.
North is to the top of the picture which is centered at 1° South Latitude and 225° West Longitude. The images in this mosaic have been re-projected to 50 mt/pixel.
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Cold, cold world...25 visteThis infrared image of Europa, showing heat radiation from its surface at a wavelength of 27 microns (millionths of a meter), provides the best view yet of Europa's daytime temperatures. Temperatures, derived from the brightness of the infrared radiation, can be determined from the colors by reference to the scale at the bottom of the image. The image, taken by Galileo spacecraft, shows the full disk of Europa, highly distorted by the relative motion of Europa and the spacecraft, centered on longitude 190°, with North at the top. The data show that midday temperatures at Europa's Equator reach about 130° Kelvin (-225 F). The surface is even colder toward the Poles and before or after midday.
Small patches of different colors on Europa's disk show regions that are warmer or cooler than their immediate surroundings: the warm patches are generally relatively dark and thus absorb more sunlight, than neighboring Regions, while the cool patches are relatively bright. In the lower left corner, heat radiation from Jupiter itself, appearing orange-red in this representation, can be seen peeking out from behind Europa's disk.
The image was taken with Galileo's PPR (Photopolarimeter-Radiometer) instrument on the spacecraft's seventh orbit around Jupiter, from a range of about 65,000 kilometers (40,389 miles). Surface temperatures derived from the strength of infrared radiation, as was done here, are called "brightness temperatures", and may be slightly in error.
The PPR instrument builds up an image by slowly scanning across the target over a period of up to one hour. The motion of Galileo relative to Europa during this time causes distortions in the satellite shape on the image, which therefore does not appear circular. The small overlapping circles that make up the image show the size of the area, about 160 kilometers (99 miles) across, covered by each individual PPR measurement. Blue spots in the dark sky in the right-hand portion of the image are due to noise.
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Shamshu Mons and Patera from 34.500 Km25 visteThis mosaic of images taken by NASA's Galileo spacecraft on February 22, 2000 shows 3 mountains and two lava-filled depressions in the Shamshu Region of Io. The dark oval feature on the left side is a depression that has been resurfaced by lava flows. The rough terrain North-East of the depression is Shamshu Mons. A 10-Km (6-mile) wide canyon oriented in North-East to South-West direction cuts this mountain. The northwestern edge of the mountain has been scalloped by erosion and it appears that the material has flowed along the canyon floor. Portions of 2 more mountains can be seen on the right side. The depression between these mountains is Shamshu Patera, a volcanic hotspot. The dark patches within it are recent and active lava flows. The northernmost edge of Shamshu Patera appears to be cutting into the mountain to its northeast. North is to the top of the picture and the Sun illuminates the surface from the West. This mosaic has a resolution of about 345 mt/pixel and covers an area of about 390x380 Km.
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Io: full disk, from about 400.000 Km26 vistePerhaps the most spectacular of all the Voyager photos of Io is this mosaic obtained by Voyager 1 on March 5, 1979, at a range of 400.000 Km (approx.). A great variety of color and albedo is seen on the surface, now thought to be the result of surface deposits of various forms of Sulfur and Sulfur Dioxide. The two great volcanoes Pele and Loki (upper left) are prominent.
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Jupiter in ultraviolet light, after being struck by Shoemaker-Levy 937 visteUltraviolet image of Jupiter taken by the Wide Field Camera of the HST. The image shows Jupiter's atmosphere at a wavelength of 2550 Angstroms after many impacts by fragments of comet Shoemaker-Levy 9. The most recent impactor is fragment R which is below the center of Jupiter (third dark spot from the right). This photo was taken 3:55 EDT on July 21, 1994, about 2,5 hours after R's impact. A large dark patch from the impact of fragment H is visible rising on the morning (left) side. Proceeding to the right, other dark spots were caused by impacts of fragments Ql, R, D and G (now one large spot) and L, with L covering the largest area of any seen thus far.
The spots are all very dark in ultraviolet light because - we think - a large amount of dust, right after the impacts, was being deposited on the upper layers of Jupiter stratosphere - and dust absorbs Sunlight.
The dark, round spot just above the center of Jupiter is the moon "Io".
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Jupiter in natural colors, after being struck by Shoemaker-Levy 937 visteThis image of the giant planet Jupiter, by NASA's HST, reveals the impact sites of fragments "D" and "G" from Comet Shoemaker-Levy 9.
The large feature was created by the impact of fragment "G" on July 18, 1994 at 3:28 a.m. EDT. It entered Jupiter's atmosphere from the south at a 45° angle and the resulting ejecta appears to have been thrown back along that direction. The smaller feature to the left of the fragment "G" impact site was created on July 17, 1994, at 7:45 a.m. EDT by the impact of fragment "D".
This image was taken 1h and 45' after fragment "G" impacted the Planet. The "G" impact has concentric rings around it, with a central dark spot that is about 2.500 Km in diameter. Such a dark spot is surrounded by a thin, dark, ring whose diameter is roughly 7.500 Km.
Last (but not least...), the dark, thick, outermost ring's inner edge has a diameter of approx. 12.000 Km (the size of Earth...).
The impact sites are located in Jupiter Southern Hemisphere at a latitude of about 44°.
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Jupiter, from Cassini36 visteOriginal caption:"This true-color simulated view of Jupiter is composed of 4 images taken by NASA's Cassini spacecraft on December 7, 2000. To illustrate what Jupiter would have looked like if the cameras had a field-of-view large enough to capture the entire Planet, the cylindrical map was projected onto a globe. The resolution is about 144 Km (about 89 miles) per pixel. Jupiter's moon Europa is casting the shadow on the Giant Gas Planet".
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The "Heat" of Jupiter22 visteOriginal caption:"These images taken through the wide angle camera near closest approach in the deep near-infrared methane band, combined with filters which sense electromagnetic radiation of orthogonal polarization, show that the light from the Poles of Jupiter is "polarized".
That is, the Poles appear bright in one image, and dark in the other. Polarized light is most readily scattered by aerosols. These images indicate that the aerosol particles at Jupiter's Poles are small and likely consist of aggregates of even smaller particles, whereas the particles at the Equator and covering the Great Red Spot are larger.
Images like these will allow scientists to ascertain the distribution, size and shape of aerosols, and consequently, the distribution of heat, in Jupiter's atmosphere".
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