Browse All : Galileo Orbiter of Arizona

Zal Patera on Jupiter's Moon …

Title	Zal Patera on Jupiter's Moon Io
Explanation	The Galileo orbiter [ http://www.jpl.nasa.gov/galileo/mission.html ]'s flyby of Io [ http://www.seds.org/nineplanets/nineplanets/io.html ] last November captured an unusual part of Jupiter [ http://antwrp.gsfc.nasa.gov/apod/jupiter.html ]'s volcanic moon. From 26,000 kilometers away, Zal Patera [ http://wwwflag.wr.usgs.gov/USGSFlag/Space/nomen/append5.html ] was found to be a cauldron of flowing lava [ http://antwrp.gsfc.nasa.gov/apod/ap991220.html ], gaseous vents [ http://antwrp.gsfc.nasa.gov/apod/ap970428.html ], and tremendous peaks [ http://antwrp.gsfc.nasa.gov/apod/ap960805.html ]. Red lava can be seen in the above picture [ http://photojournal.jpl.nasa.gov/cgi-bin/PIAGenCatalogPage.pl?PIA02527 ] erupting along the base of the volcanic caldera, while cooling black lava lines the edge of a volcanic plateau. Shadow lengths indicate that the top of Zal Patera [ http://antwrp.gsfc.nasa.gov/apod/ap990513.html ] towers nearly 5 kilometers over Io [ http://galileo.jpl.nasa.gov/moons/io.html ]'s molten surface. Galileo zoomed past Io again last month [ http://galileo.jpl.nasa.gov/news/status/status000225.html ], and has begun beaming back images taken only 200 kilometers over Io's surface [ http://antwrp.gsfc.nasa.gov/apod/ap990920.html ].

Asgard Multi-Ring Structure …

PIA01634

Jupiter

Solid-State Imaging

Title	Asgard Multi-Ring Structure on Callisto
Original Caption Released with Image	This mosaic shows the Asgard multi-ring structure on Callisto, Jupiter's second largest icy moon. The Asgard structure [ http://photojournal.jpl.nasa.gov/catalog/PIA00517 ], centered near 30 degrees north latitude, 142 degrees west longitude, is approximately 1700 km across (1,056 miles) and consists of a bright central zone surrounded by discontinuous rings. The rings are fractures that formed when Callisto's surface was struck by a large comet or asteroid. Previous analysis of Asgard identified three major zones: 1) interior bright plains in the center, 2) a zone of inward facing cliffs and, 3) a zone of discontinuous concentric troughs. The mosaic combines high resolution data of 88 meters per picture element (pixel) taken on the tenth orbit of the Galileo spacecraft around Jupiter in September 1997, with low resolution data of 1.1 kilometers (km) per pixel obtained on the third orbit in November 1996. The improved resolution of images obtained by the Solid State Imaging (SSI) system on board NASA's Galileo spacecraft allows for new insights into the Asgard multi-ring system. Galileo images show that the bright central plains includes a young dome crater, named Doh, located on its southwestern margin (at the top of the high resolution strip). Doh is about 50 km (30 miles) in diameter. Dome craters contain a central mound instead of a bowl shaped depression or the central mountain typically seen in craters. The inner rings of Asgard appear to be degraded ridges in the high resolution data, rather than inward-facing cliffs or scarps as previously interpreted from lower resolution images. In the outermost rings, dark non-ice material that slid down the walls of the troughs has made their floors darker than the surrounding cratered plains. North is to the top of the picture. The high resolution images were obtained with the clear filter of the Solid State Imaging (SSI) system when NASA's Galileo spacecraft was less than 9,500 kilometers from Callisto. There appears to be a diffuse darker stripe, beginning near the middle and continuing down the strip of higher resolution frames. This darkening is due to the processing used to place the higher resolution frames into the background context. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission or NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ].

A Chain of Impact Craters on …

PIA00514

Jupiter

Solid-State Imaging

Title	A Chain of Impact Craters on Callisto
Original Caption Released with Image	A portion of a chain of impact craters on Jupiter's moon Callisto is seen in this image taken by the Galileo spacecraft on November 4, 1996. This crater chain on Callisto is believed to result from the impact of a split object, similar to the fragments of Comet Shoemaker-Levy 9 which smashed into Jupiter's atmosphere in July of 1994. This high-resolution view, taken by Galileo's solid state imaging television camera during its third orbit around Jupiter, is of Callisto's northern hemisphere at 35 degrees north, 46 degrees west, and covers an area of about eight miles (13 kilometers) across. The smallest visible crater is about 140 yards (130 meters) across. The image was taken at a range of 974 miles (1,567 kilometers). On a global scale, Callisto is heavily cratered, indicating the great age of its surface. At the scale of this image, it was anticipated that the surface would be heavily cratered as well, however, there is a surprising lack of small craters, suggesting that one or more processes have obliterated these and other small-scale features. For example, downslope movement of ice-rich debris could bury small craters. The bright slopes visible in this picture represent places where downslope movement has taken place, exposing fresh ice surfaces. The Galileo mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ]. Background information and educational context for the images can be found at http://www2.jpl.nasa.gov/galileo/sepo/ [ http://www2.jpl.nasa.gov/galileo/sepo/ ].

Callisto's Valhalla impact s …

PIA00516

Jupiter

Solid-State Imaging

Title	Callisto's Valhalla impact structure
Original Caption Released with Image	A portion of the central zone of the large impact structure Valhalla on Jupiter's moon Callisto was imaged by the Galileo spacecraft on November 4, 1996. The area shown here is centered at 16 degrees north, 55 degrees west and is about seven miles (11 kilometers) across. This is the highest resolution picture ever taken of Callisto and shows features as small as 200 feet (60 meters) across. The formation of Valhalla occurred early in Callisto's history, however, the central zone shown here is probably younger than Valhalla's surrounding structure. This newly acquired picture shows some small craters, although they have been softened or modified by downslope movement of debris, revealing bright ice-rich surfaces. In contrast to other areas on Callisto, most of the very smallest craters appear to have been completely obliterated. This image was taken by the solid state imaging television camera onboard the Galileo spacecraft during its third orbit around Jupiter, at a distance of 757 miles (1,219 kilometers). The Galileo mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ]. Background information and educational context for the images can be found at http://www2.jpl.nasa.gov/galileo/sepo/ [ http://www2.jpl.nasa.gov/galileo/sepo/ ].

Gaspra - True and Enhanced C …

PIA00125

Sol (our sun)

Solid-State Imaging

Title	Gaspra - True and Enhanced Color
Original Caption Released with Image	These two color views of the asteroid Gaspra were produced by combining three images taken through violet, green, and infrared filters by the Galileo spacecraft on October 29, 1991, from a distance of about 16,000 kilometers (10,000 miles). The view on the left shows Gaspra in approximately true color, the surface is covered with rocks that are somewhat less grey than those on Earth's moon. In the version on the right, the colors were enhanced to bring out the muted color variations on the asteroid and to increase the ability to discriminate between surface features. The subtle variations in color may be due to slight differences in rock composition or to differences in the texture of the surface layer. These possibilities should be resolved once the rest of Galileo's Gaspra data are played back in 1992. Gaspra is about 19 by 12 by 11 kilometers (12 by 7.4 by 7 miles) and irregular in shape. The illuminated portion seen in these views is about 16 by 12 kilometers. These color images were produced for the Galileo project by the U.S. Geological survey, Flagstaff, Arizona. The Galileo project whose primary mission is the exploration of the Jupiter system in 1995-97, is managed for NASA's Office of Space Science and Applications by the Jet Propulsion Laboratory.

Craters near the south pole …

PIA00876

Jupiter

Solid-State Imaging

Title	Craters near the south pole of Callisto
Original Caption Released with Image	This image of the south polar region of the Jovian satellite Callisto was taken in twilight by the Galileo spacecraft on its eighth orbit around Jupiter. Craters ranging in size from 60 kilometers (36 miles) down to the limit of resolution are visible in this image. Scientists count the number of craters on a planetary surface to estimate its relative (and sometimes absolute) age. Note that many of the craters are not as sharp in appearance as the two large craters near the bottom of the image. This is an indication that some process has eroded the craters since their formation. This image is centered at 82.5 south latitude and 62.6 west longitude, and covers an area approximately 370 kilometers (220 miles) by 280 kilometers (170 miles). North is toward the top of the image. This image was taken on May 6, 1997 by the Solid State Imaging system (CCD) on board NASA's Galileo spacecraft at a resolution of 676 meters (417 feet) per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Callisto Scarp Mosaic

PIA00561

Jupiter

Solid-State Imaging

Title	Callisto Scarp Mosaic
Original Caption Released with Image	This mosaic of two images shows an area within the Valhalla region on Jupiter's moon, Callisto. North is to the top of the mosaic and the Sun illuminates the surface from the left. The smallest details that can be discerned in this picture are knobs and small impact craters about 155 meters (170 yards) across. The resolution is 46 meters (50 yards) per picture element, and the mosaic covers an area approximately 33 kilometers (20 miles) across. A prominent fault scarp crosses the mosaic. This scarp is one of many structural features that form the Valhalla multi-ring structure, which has a diameter of 4,000 kilometers (2,485 miles). Scientists believe Valhalla is the result of a large impact early in the history of Callisto. Several smaller ridges are found parallel to the prominent scarp. Numerous impact craters ranging in size from 155 meters (170 yards) to 2.5 kilometers (1.5 miles) are seen in the mosaic. The images which form this mosaic were obtained by the solid state imaging system aboard NASA's Galileo spacecraft on Nov. 4, 1996 (Universal Time). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo.

Callisto Crater Chain Mosaic

PIA00549

Jupiter

Solid-State Imaging

Title	Callisto Crater Chain Mosaic
Original Caption Released with Image	This mosaic of three images shows an area within the Valhalla region on Jupiter's moon, Callisto. North is to the top of the mosaic and the Sun illuminates the surface from the left. The smallest details that can be discerned in this picture are knobs and small impact craters about 160 meters (175 yards) across. The mosaic covers an area approximately 45 kilometers (28 miles) across. It shows part of a prominent crater chain located on the northern part of the Valhalla ring structure. Crater chains can form from the impact of material ejected from large impacts (forming secondary chains) or by the impact of a fragmented projectile, perhaps similar to the Shoemaker-Levy 9 cometary impacts into Jupiter in July 1994. It is believed this crater chain was formed by the impact of a fragmented projectile. The images which form this mosaic were obtained by the solid state imaging system aboard NASA's Galileo spacecraft on Nov. 4, 1996 (Universal Time). Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at http:// www.jpl.nasa.gov/galileo/sepo.

The Valhalla Multi-ring Structure on Callisto

The Valhalla Multi-ring Stru …

PIA01649

Jupiter

Solid-State Imaging

Title	The Valhalla Multi-ring Structure on Callisto
Original Caption Released with Image	These images of Callisto, the outermost of the Galilean satellites of Jupiter, reveal a surface characterized by impact craters. The global view (lower left) is dominated by a large bulls-eye feature, the Valhalla multi-ring structure, consisting of a bright inner region about 600 kilometers (370 miles) across. Valhalla's 4,000 kilometer(2,500 mile) diameter make it one of the largest impact features in the solar system. Callisto is 4,800 kilometers (3,000 miles) in diameter. In this global view, the sun illuminates the surface from near the center, in the same way a full moon is seen from Earth when illuminated by the sun. The image on the right shows part of Valhalla at moderate resolution. At this resolution, the surface is appears to be somewhat smooth, with a lack of numerous small impact craters. Valhalla's outer rings are clearly seen to consist of troughs which could be fractures in the crust which resulted from the impact. The bright central plains possibly were created by the excavation and ejection of "cleaner" ice or liquid water from beneath the surface, with a fluid-like massfilling the crater bowl after impact. North is to the top of the picture. For the moderate resolution view on the right, the sun illuminates the surface from the left and the resolution is approximately 400 meters per picture element. The images were obtained on June 25, 1997 by the solid state imaging (SSI)system on NASA's Galileo spacecraft at a range of about 40,000 kilometers(25,000 miles) from Callisto during Galileo's ninth orbit of Jupiter. The global image on the left is centered at 0.5 degrees south latitude and 56 degrees longitude. The resolution is 14 kilometers per picture element. The images were obtained on November 5, 1997 at a range of 68,400 kilometers(42,400 miles) during Galileo's eleventh orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]

Impact Craters on Icy Callisto: Doh crater and Asgard

Impact Craters on Icy Callis …

PIA01648

Jupiter

Solid-State Imaging

Title	Impact Craters on Icy Callisto: Doh crater and Asgard
Original Caption Released with Image	This composite of Jupiter's icy moon Callisto combines data from two orbits showing several types of impact craters. North is to the top of the picture, the sun illuminates the surface from the east. The global image on the right shows one of the largest impact structures on Callisto, the Asgard multi-ring structure located near 30 degrees north latitude, 142 degrees west longitude. The Asgard structure is approximately 1700 kilometers (1,054 miles) across and consists of a bright central zone surrounded by discontinuous rings. The rings include degraded ridges near the central zone and troughs at the outer margin, which resulted from deformation of the icy crust following impact. Smaller impacts have smashed into Callisto after the formation of Asgard. The young, bright-rayed crater Burr located on the northern part of Asgardis about 75 kilometers (46 miles) across. Galileo images show a third type of impact crater in this image, a dome crater named Doh, located in the bright central plains of Asgard. Doh (left image) is about 55 kilometers (34 miles)in diameter, while the dome is about 25 kilometers (15 miles) across. Dome craters contain a central mound instead of a bowl shaped depression or central mountain (peak) typically seen in larger impact craters. This type of crater could represent penetration into a slushy zone beneath the surface of the Asgard impact. The global image on the right was taken on November 4, 1996, at a distance of 111,900 kilometers (69,400 miles) by the solid state imaging (SSI) camera onboard NASA's Galileo spacecraft during its third orbit around Jupiter. The image on the left was obtained at a resolution of 90 meters (295 feet)per picture element on September 16, 1997 during Galileo's tenth orbit when the spacecraft was less than 9,500 kilometers (6,000 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URLhttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]

Moderate-resolution view of Callisto's surface

Moderate-resolution view of …

PIA00898

Jupiter

Solid-State Imaging

Title	Moderate-resolution view of Callisto's surface
Original Caption Released with Image	This five-frame mosaic of the Jovian satellite Callisto shows a surface densely populated with impact craters. However, close inspection of this image reveals differences among the craters. For example, a few of the craters contain central dome-shaped features, while others contain depressions, or pits, within the crater floor. Scientists study differences among craters such as these to learn more about both the surface that was struck by an impactor, and the impactor itself. These images were obtained by the Galileo spacecraft on its eighth orbit around Jupiter at a distance of 48,000 km from Callisto. The mosaic is centered at 31 S. latitude and 122 W. longitude, and covers an area approximately 700 kilometers (420 miles) by 900 kilometers (540 miles)-- somewhat larger than Montana. The finest details that can be discerned in this picture are about 1.8 kilometers across (0.93 km/pixel). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Callisto's Equatorial Region

PIA00745

Jupiter

Solid-State Imaging

Title	Callisto's Equatorial Region
Original Caption Released with Image	This mosaic covers part of the equatorial region of Jupiter's moon, Callisto. The mosaic combines six separate image frames obtained by the solid state imaging (CCD) system on NASA's Galileo spacecraft during its ninth orbit around Jupiter. North is to the top of the picture. The mosaic shows several new features and characteristics of the surface revealed by Galileo. These include deposits that may represent landslides in the southern and southwestern floors of many craters. Two such deposits are seen in a 12 kilometer (7.3 mile) crater in the west-central part of the image, and in a 23 kilometer (14 mile) crater just north of the center of the image. Also notable are several sinuous valleys emanating from the southern rims of 10 to 15 kilometer (6.2 to 9.3 mile) irregular craters in the west-central part of the image. The pervasive local smoothing of Callisto's surface is well represented in the plains between the craters in the southeastern part of the image. Possible oblique impacts are suggested by the elongated craters in the northeastern and southeastern parts of the image. The mosaic, centered at 7.4 degrees south latitude and 6.6 degrees west longitude, covers an area of approximately 315 by 215 kilometers (192 by 131 miles). The sun illuminates the scene from the west (left). The smallest features that can be seen are about 300 meters (993 feet) across. The images were obtained on June 25, 1997, when the spacecraft was at a range of 15,200 kilometers (8,207 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

The Asgard Hemisphere of Cal …

PIA01100

Jupiter

Solid-State Imaging

Title	The Asgard Hemisphere of Callisto
Original Caption Released with Image	False color view of a portion of the leading hemisphere of Jupiter's moon Callisto as seen through the infrared filters of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. North is to the top of the picture and the sun illuminates the surface from the east. More recent impacts have excavated bright, relatively clean ice from beneath Callisto's battered surface. Callisto's dark mottled appearance may be due to contamination by non-ice components contributed by impactors or concentrated in a residue as ice is removed. This color composite image is centered on longitude 139 West and encompasses an area about 1000 miles (1600 kilometers) by 2470 miles (4000 kilometers). The images were obtained on November 3rd, 1996. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Har Crater on Callisto

PIA01054

Jupiter

Solid-State Imaging

Title	Har Crater on Callisto
Original Caption Released with Image	This image shows a heavily cratered region near Callisto's equator. It was taken by the Galileo spacecraft Solid State Imaging (CCD) system on its ninth orbit around Jupiter. North is to the top of the image. The 50 kilometer (30 mile) double ring crater in the center of the image is named Har. Har displays an unusual rounded mound on its floor. The origin of the mound is unclear but probably involves uplift of ice-rich materials from below, either as a "rebound" immediately following the impact that formed the crater or as a later process. Har is older than the prominent 20 kilometer (12 mile) crater superposed on its western rim. The large crater partially visible in the northeast corner of the image is called Tindr. Chains of secondary craters (craters formed from the impact of materials thrown out of the main crater during an impact) originating from Tindr crosscut the eastern rim of Har. The image, centered at 3.3 degrees south latitude and 357.9 degrees west longitude, covers an area of 120 kilometers by 115 kilometers (75 miles by 70 miles). The sun illuminates the scene from the west (left). The smallest distinguishable features in the image are about 294 meters (973 feet) across. This image was obtained on June 25, 1997, when Galileo was 14,080 kilometers (8,590 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

Large impact on Callisto`s southern hemisphere

Large impact on Callisto`s s …

PIA01077

Jupiter

Solid-State Imaging

Title	Large impact on Callisto`s southern hemisphere
Original Caption Released with Image	This mosaic of images showing a large 200 kilometer (120 mile) diameter impact crater on Callisto's southern hemisphere was obtained by the solid state imaging (CCD) system on board NASA's Galileo spacecraft during its eighth orbit of Jupiter. This crater is characterized by a bright circular area surrounded by a darker material excavated and ejected by the impact. Beyond this is a zone of rays which are oriented radially outward and contain material also thrown from the crater. Fewer smaller impact craters are visible in the ejecta blanket surrounding the large crater than in the areas more distant from the crater. This lack of craters superposed on the ejecta blanket and on the crater itself, together with the brightness of the central zone, is evidence that the large crater is a relatively young feature on Callisto. Scientists use information such as the number of craters in a given area together with the principle of superposition (in which younger landforms are "on top" of older features) to determine the relative ages of features and terrains. North is to the top of the mosaic with the sun illuminating the surface from the left. The mosaic, centered at 55 degrees south latitude and 30 degrees west longitude, covers an area approximately 1400 kilometers (850 miles) by 1235 kilometers (740 miles), at a resolution of 867 meters (945 yards) per picture element. The images which make up this mosaic were taken on May 6, 1997, from an altitude of approximately 43,000 kilometers (26,000 miles) above the surface of Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Landslides on Callisto

PIA01095

Jupiter

Solid-State Imaging

Title	Landslides on Callisto
Original Caption Released with Image	Recent Galileo images of the surface of Jupiter's moon Callisto have revealed large landslide deposits within two large impact craters seen in the right side of this image. The two landslides are about 3 to 3.5 kilometers (1.8 to 2.1 miles) in length. They occurred when material from the crater wall failed under the influence of gravity, perhaps aided by seismic disturbances from nearby impacts. These deposits are interesting because they traveled several kilometers from the crater wall in the absence of an atmosphere or other fluids which might have lubricated the flow. This could indicate that the surface material on Callisto is very fine-grained, and perhaps is being "fluffed" by electrostatic forces which allowed the landslide debris to flow extended distances in the absence of an atmosphere. This image was acquired on September 16th, 1997 by the Solid State Imaging (CCD) system on NASA's Galileo spacecraft, during the spacecraft's tenth orbit around Jupiter. North is to the top of the image, with the sun illuminating the scene from the right. The center of this image is located near 25.3 degrees north latitude, 141.3 degrees west longitude. The image, which is 55 kilometers (33 miles) by 44 kilometers (26 miles) across, was acquired at a resolution of 100 meters per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov.

Io Eclipse/Volcanic Eruption

PIA00704

Sol (our sun)

Solid-State Imaging

Title	Io Eclipse/Volcanic Eruption
Original Caption Released with Image	This image was acquired while Io was in eclipse (in Jupiter's shadow) during Galileo's eighth orbit, and reveals several dynamic processes. The most intense features are red, while glows of lesser intensity are yellow or green, and very faint glows appear blue in this color-coded image. The small red or yellow spots mark the sites of high-temperature magma erupting onto the surface in lava flows or lava lakes. This image reveals a field of bright spots near Io's sub-Jupiter point (right-hand side of image). The sub-Jupiter hemisphere always faces Jupiter just as the Moon's nearside always faces Earth. There are extended diffuse glows on the equatorial limbs or edges of the planet (right and left sides). The glow on the left is over the active volcanic plume Prometheus, but whereas Prometheus appears to be 75 kilometers (46.6 miles) high in reflected light, here the diffuse glow extends about 800 kilometers (497 miles) from Io's limb. This extended glow indicates that gas or small particles reach much greater heights than the dense inner plume. The diffuse glow on the right side reaches a height of 400 kilometers (249 miles), and includes a prominence with a plume-like shape. However, no volcanic plume has been seen at this location in reflected light. This type of observation is revealing the relationships between Io's volcanism, atmosphere and exosphere. Taken on May 6, 1997, north is toward the top. The image was taken with the clear filter of the solid state imaging (CCD) system on NASA's Galileo spacecraft at a range of 1.8 million kilometers (1.1 million miles). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Large Craters in Callisto's Southern Hemisphere

Large Craters in Callisto's …

PIA01219

Jupiter

Solid-State Imaging

Title	Large Craters in Callisto's Southern Hemisphere
Original Caption Released with Image	NASA's Galileo spacecraft provides a new view of this heavily cratered region in the southern hemisphere of the icy Jovian satellite Callisto. The region was not observed by NASA's Voyager spacecraft. Craters ranging in diameter from the 1.85 kilometer (1.13 mile) limit of resolution up to more than 70 kilometers (43 miles) can be observed in this image. Although all craters are generally round in outline, details in their structures vary with both size and relative age. Bright spots in the center of smaller craters (up to approximately 20 kilometers (12 miles)) are central peaks. Larger craters (up to the 51 kilometer (31 mile) wide crater in the east central part of the image) exhibit central pits or depressions. The largest crater, called Thrainn, has a diameter of 74 kilometers (45 miles) and is located in the southernmost corner of the image. This crater contains a broad central uplift, or dome, and has a highly eroded rim. In contrast, the 70 kilometer (43 mile) crater Audr, located along the northern margin of the image, is flat-bottomed, and has a less degraded and generally rounder rim. If erosional or degradational forces have been roughly constant with time on Callisto, scientists viewing this image can assume that Audr is relatively younger than Thrainn by noting the less degraded or fresher appearance of its rim. The differences in crater floor features between these two similarly sized craters could have been produced by differences in the impacting bodies that produced them, differences in the crustal materials in which the craters formed, or simply by a gradual evolution of crater floor shape with time. North is to the top of the image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter on May 6th, 1997. The center of the image is located at 34 degrees south latitude, 84 degrees west longitude, and was taken when the spacecraft was approximately 48,430 kilometers (29,542 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Heavy Cratering near Callisto's South Pole

Heavy Cratering near Callist …

PIA01221

Jupiter

Solid-State Imaging

Title	Heavy Cratering near Callisto's South Pole
Original Caption Released with Image	Images from NASA's Galileo spacecraft provide new insights into this region near Callisto's south pole. This two frame mosaic shows a heavily cratered surface with smooth plains in the areas between craters. North is to the top of the image. The smoothness of the plains appears to increase toward the south pole, approximately 480 kilometers (293 miles) south of the bottom of the image. This smoothness of Callisto's surface was not evident in images taken during the 1979 flyby of NASA's Voyager spacecraft because the resolution was insufficient to show the effect. This smooth surface, and the process(es) that cause it, are among the most intriguing aspects of Callisto. Although not fully understood, the process(es) responsible for this smoothing could include erosion by tiny meteorites and energetic ions. Some craters, such as Keelut, the 47 kilometer (29 mile) crater in the lower right corner, have sharp, well defined rims. Keelut contains an inner ring surrounding a central depression about 17 kilometers (11 miles) in diameter. Keelut, and the more irregularly shaped, degraded Reginleif, the 32 kilometer (19.5 mile) crater in the top center of the image, are very shallow and have flat floors. Crater forms can be seen down to less than 2 kilometers (1.2 miles) in diameter in the image. Each picture element (pixel) in this image is approximately 0.68 kilometers (0.41 miles) across. This image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter, on May 6th, 1997. The center of the image is located at 71.3 degrees south latitude, 97.6 degrees west longitude, and was taken when the spacecraft was approximately 35,470 kilometers (21,637 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Mass wasting in craters near the south pole of Callisto

Mass wasting in craters near …

PIA01222

Jupiter

Solid-State Imaging

Title	Mass wasting in craters near the south pole of Callisto
Original Caption Released with Image	Craters ranging in diameter from the limit of resolution, approximately 1.35 kilometers (0.82 miles), up to the remnants of a heavily degraded two-ringed basin (center of the image), approximately 90 kilometers (55 miles) in diameter, can be seen in this image of a region near Callisto's south pole. Craters in this image exhibit a wide variety of degradational (erosional) states, including what appear to be landslide or slump deposits, best seen in the southwestern part of the bright 21 kilometer crater Randver, just east of the center of the image. The relative youth of Randver is evidenced by its bright and easily identifiable ejecta blanket (the materials ejected during the formation of the crater). The northeast facing slopes in this region are typically the brightest portion of the crater rims. Craters in the south and southwestern portions of this image are the most highly modified and degraded, and are therefore considered to be the oldest craters in the area. North is to the top of the image which was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter on May 6, 1997. The center of the image is located 73.2 degrees south latitude, 54.4 degrees west longitude, and was taken when the spacecraft was approximately 35,464 kilometers (21,633 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Craters in a Newly Imaged Area on Callisto

Craters in a Newly Imaged Ar …

PIA01225

Jupiter

Solid-State Imaging

Title	Craters in a Newly Imaged Area on Callisto
Original Caption Released with Image	This two frame mosaic of images from NASA's Galileo spacecraft shows an area in the southern hemisphere of Jupiter's moon, Callisto, that was not imaged during the 1979 flyby of NASA's Voyager spacecraft. North is to the top of the image. Craters can be seen in this mosaic from less than 3 kilometers (Picture elements in this image are 0.93 kilometers (0.63 miles) across.) up to the 83 kilometer (51 mile) central dome crater Barri, just left (west) of the center of the mosaic. The ejecta (material thrown from the crater during its formation) from Barri can be seen as a diffuse halo or ring stretching to approximately one crater radius from the outer crater rim. The smaller, younger craters are brighter and have sharper, more pronounced rims. Thorir, a 43 kilometer (26 mile) crater just left of center, is cut by a central valley or fracture. This cross-cutting relationship indicates that Thorir is older than the event that produced this fracture. Scientists study the different crater morphologies (shapes) to determine crustal and surface conditions since the craters were formed on these icy moons. This image was taken by the Galileo spacecraft's solid state imaging (CCD) system during its eighth orbit around Jupiter, on May 6th, 1997. The center of the image is located at 30.2 degrees south latitude, 66.1 degrees west longitude, and it was taken when the spacecraft was approximately 48,549 kilometers (29,615 miles) from Callisto. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Ancient Impact Basin on Euro …

PIA00702

Jupiter

Solid-State Imaging

Title	Ancient Impact Basin on Europa
Original Caption Released with Image	This feature on Europa was seen as a dark, diffuse circular patch on a previous Galileo global image of Europa's leading hemisphere on April 3, 1997. The "bulls-eye" pattern appears to be a 140- kilometer (86-mile) wide impact scar (about the size of the island of Hawaii) which formed as the surface fractured minutes after a mountain-sized asteroid or comet slammed into the satellite. This approximately 214-kilometer (132-mile) wide picture is the product of three images which have been processed in false color to enhance shapes and compositions. North is toward the top of this picture, which is illuminated from sunlight coming from the west. This color composite reveals a sequence of events which have modified the surface of Europa. The earliest event was the impact which formed the Tyre structure at 34 degrees north latitude and 146.5 degrees west longitude. The impact was followed by the formation of the reddish lines superposed on Tyre. The red color designates areas that are probably a dirty water ice mixture. The fine blue-green lines crossing the region from west to east appear to be ridges which formed after the crater. The images were taken on April 4, 1997, at a resolution of 595 meters (1950 feet) per picture element and a range of 29,000 kilometers (17,900 miles). The images were taken by Galileo's solid state imaging (CCD) system. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Global Color Variations on C …

PIA01298

Jupiter

Solid-State Imaging

Title	Global Color Variations on Callisto
Original Caption Released with Image	Jupiter's icy moon Callisto is shown in approximate natural color (left) and in false color to enhance subtle color variations (right). This image of Callisto's Jupiter-facing hemisphere shows the ancient, multi-ring impact structure Valhalla just above the center of the image. Valhalla, possibly created by a large asteroid or comet which impacted Callisto, is the largest surface feature on this icy moon. Valhalla consists of a bright inner region, about 600 kilometers (360 miles) in diameter surrounded by concentric rings 3000 to 4000 kilometers (1800-2500 miles) in diameter. The bright central plains were possibly created by the excavation and ejection of "cleaner" ice from beneath the surface, with a fluid-like mass (impact melt) filling the crater bowl after impact. The concentric rings are fractures in the crust resulting from the impact. The false color in the right image shows new information, including ejecta from relatively recent craters, which are often not apparent in the natural color image. The color also reveals a gradual variation across the moon's hemisphere, perhaps due to implantation of materials onto the surface from space. These color images were obtained with the 1 micrometer (infrared), green, and violet filters of the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The false color is created from ratios of infrared/violet and its inverse (violet/infrared) which are then combined so the infrared/violet, green, and violet/infrared are assigned to red, green, and blue in a composite product. North is to the top of the picture and the sun illuminates the surface from near the center, in the same way a full moon is seen from Earth when illuminated by the sun. The image, centered at 0.5 degrees south latitude and 56.3 degrees longitude, covers an area about 4800 by 4800 kilometers. The resolution is 14 kilometers per picture element. The images were taken on November 5, 1997 at a range of 68,400 kilometers (41,000 miles) during Galileo's eleventh orbit of Jupiter. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Opposite Side of Callisto from Valhalla Impact

Opposite Side of Callisto fr …

PIA02593

Jupiter

Solid-State Imaging

Title	Opposite Side of Callisto from Valhalla Impact
Original Caption Released with Image	The heavily cratered portion of the surface of Jupiter's moon Callisto, seen in this image recorded by NASA's Galileo spacecraft, resembles most of Callisto that's been seen in high resolution. This adds evidence to a theory that Callisto may hold an underground ocean. The area in the image is the opposite point, or antipode, of Callisto's Valhalla impact basin. The antipode of any point on a sphere is the opposite point on a line through the center of the sphere. Antipodes of major impact sites on some other worlds similar in size to Callisto, such as Mercury and Earth's moon, show a grooved and hilly terrain attributed to seismic shocks focusing on those points from the distant impacts. The antipode of Mercury's Caloris impact site [ http://photojournal.jpl.nasa.gov/catalog/PIA02445 ] is one example. When Galileo flew near Callisto on May 25, 2001, scientists sought an image to check the Valhalla antipode for similar signs of disruption. Computer modeling has suggested that if Callisto had a water layer in its interior, that layer would have dispersed the seismic shock waves from the ancient Valhalla impact. The absence of grooved and hilly terrain at the Valhalla antipode is consistent with that possibility. Magnetic-field measurements have previously suggested that Callisto has a layer of liquid water deep below its surface. This image, taken from a distance of 32,000 kilometers (about 20,000 miles) shows details at the Valhalla antipode down to a size of about 330 meters (about 1,250 feet)across. Callisto is the outermost of Jupiter's four large moons. Its surface of ice and rock is the most heavily cratered of any moon in the solar system. For a view of this image in context click here. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the spacecraft and its discoveries is available on the Galileo home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ].

Opposite Side of Callisto fr …

PIA02593

Jupiter

Solid-State Imaging

Title	Opposite Side of Callisto from Valhalla Impact
Original Caption Released with Image	The heavily cratered portion of the surface of Jupiter's moon Callisto, seen in this image recorded by NASA's Galileo spacecraft, resembles most of Callisto that's been seen in high resolution. This adds evidence to a theory that Callisto may hold an underground ocean. The area in the image is the opposite point, or antipode, of Callisto's Valhalla impact basin. The antipode of any point on a sphere is the opposite point on a line through the center of the sphere. Antipodes of major impact sites on some other worlds similar in size to Callisto, such as Mercury and Earth's moon, show a grooved and hilly terrain attributed to seismic shocks focusing on those points from the distant impacts. The antipode of Mercury's Caloris impact site [ http://photojournal.jpl.nasa.gov/catalog/PIA02445 ] is one example. When Galileo flew near Callisto on May 25, 2001, scientists sought an image to check the Valhalla antipode for similar signs of disruption. Computer modeling has suggested that if Callisto had a water layer in its interior, that layer would have dispersed the seismic shock waves from the ancient Valhalla impact. The absence of grooved and hilly terrain at the Valhalla antipode is consistent with that possibility. Magnetic-field measurements have previously suggested that Callisto has a layer of liquid water deep below its surface. This image, taken from a distance of 32,000 kilometers (about 20,000 miles) shows details at the Valhalla antipode down to a size of about 330 meters (about 1,250 feet)across. Callisto is the outermost of Jupiter's four large moons. Its surface of ice and rock is the most heavily cratered of any moon in the solar system. For a view of this image in context click here. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the spacecraft and its discoveries is available on the Galileo home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ].

Callisto Close-up with Jagge …

PIA03455

Jupiter

Solid-State Imaging

Title	Callisto Close-up with Jagged Hills
Original Caption Released with Image	The highest-resolution views ever obtained of any of Jupiter's moons, taken by NASA's Galileo spacecraft in May 2001, reveal numerous bright, sharp knobs covering a portion of Jupiter's moon Callisto. The knobby terrain seen throughout the top inset is unlike any seen before on Jupiter's moons. The spires are very icy but also contain some darker dust. As the ice erodes, the dark material apparently slides down and collects in low-lying areas. Over time, as the surface continues to erode, the icy knobs will likely disappear, producing a scene similar to the bottom inset. The number of impact craters in the bottom image indicates that erosion has essentially ceased in the dark plains shown in that image, allowing impact craters to persist and accumulate. The knobs are about 80 to 100 meters (260 to 330 feet) tall, and they may consist of material thrown outward from a major impact billions of years ago. The areas captured in the images lie south of Callisto's large Asgard impact basin. The smallest features discernable in the images are about 3 meters (10 feet) across. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the spacecraft and its discoveries is available on the Galileo home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ].

Topography of Io (color)

PIA00740

Jupiter

Solid-State Imaging

Title	Topography of Io (color)
Original Caption Released with Image	The images used to create this color composite of Io were acquired by Galileo during its ninth orbit (C9) of Jupiter and are part of a sequence of images designed to map the topography or relief on Io and to monitor changes in the surface color due to volcanic activity. Obtaining images at low illumination angles is like taking a picture from a high altitude around sunrise or sunset. Such lighting conditions emphasize the topography of the volcanic satellite. Several mountains up to a few miles high can be seen in this view, especially near the upper right. Some of these mountains appear to be tilted crustal blocks. Most of the dark spots correspond to active volcanic centers. North is to the top of the picture which merges images obtained with the clear, red, green, and violet filters of the solid state imaging (CCD) system on NASA's Galileo spacecraft. . The resolution is 8.3 kilometers per picture element. The image was taken on June 27, 1997 at a range of 817,000 kilometers by the solid state imaging (CCD) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Arizona-sized Io Eruption

PIA00744

Jupiter

Solid-State Imaging

Title	Arizona-sized Io Eruption
Original Caption Released with Image	These images of Jupiter's volcanic moon, Io, show the results of a dramatic event that occurred on the fiery satellite during a five-month period. The changes, captured by the solid state imaging (CCD) system on NASA's Galileo spacecraft, occurred between the time Galileo acquired the left frame, during its seventh orbit of Jupiter, and the right frame, during its tenth orbit. A new dark spot, 400 kilometers (249 miles) in diameter, which is roughly the size of Arizona, surrounds a volcanic center named Pillan Patera. Galileo imaged a 120 kilometer (75 mile) high plume erupting from this location during its ninth orbit. Pele, which produced the larger plume deposit southwest of Pillan, also appears different than it did during the seventh orbit, perhaps due to interaction between the two large plumes. Pillan's plume deposits appear dark at all wavelengths. This color differs from the very red color associated with Pele, but is similar to the deposits of Babbar Patera, the dark feature southwest of Pele. Some apparent differences between the images are not caused by changes on Io's surface, but rather are due to differences in illumination, emission and phase angles. This is particularly apparent at Babbar Patera. North is to the top of the images. The left frame was acquired on April 4th, 1997, while the right frame was taken on Sept. 19th, 1997. The images were obtained at ranges of 563,000 kilometers (350,000 miles) for the left image, and 505,600 kilometers (314,165 miles) for the right. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo.

Eclipse Images of Io (3 view …

PIA00739

Jupiter

Solid-State Imaging

Title	Eclipse Images of Io (3 views)
Original Caption Released with Image	These three images of Io in eclipse (top) show volcanic hot spots and airglow associated with volcanic plumes and Io's atmosphere. They were acquired by NASA's Galileo spacecraft during three separate orbits of Jupiter when the moon was in Jupiter's shadow. Brightnesses are color-coded from red which displays the highest intensity to dark blue which displays zero intensity (no light). Below them are the corresponding views of Io in reflected sunlight, reprojected from a global mosaic of images obtained during Galileo's first and second orbits of Jupiter. These lit views help to identify the locations of the hot spots seen in the eclipse images. The grid marks are at 15 degree intervals of latitude and longitude. North is to the top. In the eclipse images (top) small red ovals and perhaps some small green areas are due to thermal emission from volcanic hot spots with temperatures hotter than about 700 kelvin (about 1000 degrees Fahrenheit). Diffuse greenish areas seen near the limb or edge of the moon are probably the result of auroral and/or airglow emissions of neutral species of oxygen or sulfur in volcanic plumes and in Io's patchy atmosphere. All images were acquired by the solid state imaging (CCD) system on NASA's Galileo spacecraft. The top left image was obtained during the spacecraft's fourth orbit (E4) on December 17, 1996, the top middle image during the sixth orbit (E6) on February 21, 1997, and the top right image during the first orbit (G1) on June 29th, 1996. The relatively long exposures used to obtain these eclipse images lead to some smearing of the picture elements which reduces the actual resolution. Unsmeared they would have resolutions of 17.6, 9.1, and 10.5 kilometers per picture element respectively (left to right). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). Concurrent results from Galileo's exploration of Io appear in the October 15th, 1997 issue of Geophysical Research Letters. The papers are: * Temperature and Area Constraints of the South Volund Volcano on Io from the NIMS and SSI Instruments during the Galileo G1 Orbit, by A.G. Davies, A.S. McEwen, R. Lopes-Gautier, L. Keszthelyi, R.W. Carlson and W.D. Smythe. * High-temperature hot spots on Io as seen by the Galileo Solid-State Imaging (SSI) experiment, by A. McEwen, D. Simonelli, D. Senske, K. Klassen, L. Keszthelyi, T. Johnson, P. Geissler, M. Carr, and M. Belton. * Io: Galileo evidence for major variations in regolith properties, by D. Simonelli, J. Veverka, and A. McEwen. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Topography and Volcanoes on …

PIA00738

Jupiter

Solid-State Imaging

Title	Topography and Volcanoes on Io (color)
Original Caption Released with Image	The images used to create this enhanced color composite of Io were acquired by NASA's Galileo spacecraft during its seventh orbit (G7) of Jupiter. Low sun angles near the terminator (day-night boundary near the left side of the image) offer lighting conditions which emphasize the topography or relief on the volcanic satellite. The topography appears very flat near the active volcanic centers such as Loki Patera (the large dark horse-shoe shaped feature near the terminator) while a variety of mountains and plateaus exist elsewhere. The big reddish-orange ring in the lower right is formed by material deposited from the eruption of Pele, Io's largest volcanic plume. North is to the top of this picture which merges images obtained with the clear, red, green, and violet filters of the solid state imaging (CCD) system on NASA's Galileo spacecraft. The resolution is 6.1 kilometers per picture element. The images were taken on April 4th, 1997 at a range of 600,000 kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech). Concurrent results from Galileo's exploration of Io appear in the October 15th, 1997 issue of Geophysical Research Letters. The papers are: * Temperature and Area Constraints of the South Volund Volcano on Io from the NIMS and SSI Instruments during the Galileo G1 Orbit, by A.G. Davies, A.S. McEwen, R. Lopes-Gautier, L. Keszthelyi, R.W. Carlson and W.D. Smythe. * High-temperature hot spots on Io as seen by the Galileo Solid-State Imaging (SSI) experiment, by A. McEwen, D. Simonelli, D. Senske, K. Klassen, L. Keszthelyi, T. Johnson, P. Geissler, M. Carr, and M. Belton. * Io: Galileo evidence for major variations in regolith properties, by D. Simonelli, J. Veverka, and A. McEwen. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Geologic Landforms on Io (Ar …

PIA01105

Jupiter

Solid-State Imaging

Title	Geologic Landforms on Io (Area 3)
Original Caption Released with Image	Shown here is one of the topographic mapping images of Jupiter's moon Io (Latitude: +2 to +65 degrees, Longitude: 150 to 223 degrees) acquired by NASA's Galileo spacecraft, revealing a great variety of landforms. There are rugged mountains several miles high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. There are also dark lava flows and bright deposits of SO2 frost or other sulfurous materials, which have no discernable topographic relief at this scale. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. North is to the top of the picture and the sun illuminates the surface from the left. The image covers an area about 2000 kilometers wide and the smallest features that can be discerned are 2.5 kilometers in size. This image was taken on November 6th, 1996, at a range of 245,719 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Geologic Landforms on Io (Ar …

PIA01106

Jupiter

Solid-State Imaging

Title	Geologic Landforms on Io (Area 4)
Original Caption Released with Image	Shown here is one of the topographic mapping images of Jupiter's moon Io (Latitude: -60 to 20 degrees, Longitude: 180 to 270 degrees) acquired by NASA's Galileo spacecraft, revealing a great variety of landforms. There are rugged mountains several miles high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. There are also dark lava flows and bright deposits of SO2 frost or other sulfurous materials, which have no discernable topographic relief at this scale. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. The large oval on the left-hand side is the fallout deposit from Pele, the largest volcanic eruption plume on Io, over 200 miles high when active. North is to the top of the picture and the sun illuminates the surface from the left. The image covers an area about 2390 kilometers wide and the smallest features that can be discerned are 3.0 kilometers in size. This image was taken on November 6th, 1996, at a range of 294,000 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Geologic Landforms on Io (Ar …

PIA01103

Jupiter

Solid-State Imaging

Title	Geologic Landforms on Io (Area 1)
Original Caption Released with Image	Shown here is one of the topographic mapping images of Jupiter's moon Io (Latitude: -20 to +65 degrees, Longitude: 90 to 175 degrees) acquired by NASA's Galileo spacecraft, revealing a great variety of landforms. There are rugged mountains several miles high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. There are also dark lava flows and bright deposits of SO2 frost or other sulfurous materials, which have no discernable topographic relief at this scale. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. North is to the top of the picture and the sun illuminates the surface from the left. The image covers an area about 2600 kilometers wide and the smallest features that can be discerned are 3.5 kilometers in size. This image was taken on November 6th, 1996, at a range of 339,400 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Terrain on Europa under Changing Lighting Conditions

Terrain on Europa under Chan …

PIA01102

Jupiter

Solid-State Imaging

Title	Terrain on Europa under Changing Lighting Conditions
Original Caption Released with Image	These images obtained by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft show the same region of Europa under different lighting conditions. The upper image was obtained on June 28th, 1996 during Galileo's first orbit around Jupiter under "high-sun" conditions -- the equivalent of taking a picture from a high altitude at noon (with the sun directly overhead). Note that albedo (light/dark) features are emphasized. Compare this to the lower image containing a higher-resolution inset. This (inset) image was taken on November 6th, 1996 during the spacecraft's third orbit under "low-sun" illumination -- the equivalent of taking a picture from a high altitude at sunrise or sunset. Note that in this image the albedo features are not readily apparent. Instead, the topography of the terrain is emphasized. Planetary geologists use information from images acquired under a variety of lighting conditions to identify different types of structures and interpret how they formed. Note that the bright linear features in the upper image are seen to be ridges in the lower image. The circular feature on the right side of both images, Cilix, is approximately 25 kilometers (15 miles) across. The area seen in the upper image is 312 kilometers (187 miles) by 570 kilometers (342 miles) across, the area covered by the inset is 36 kilometers (22 miles) by 315 kilometers (190 miles) across. Both of these images are centered near 2 South latitude, 185 West longitude. North is to the top of the frames. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Geologic Landforms on Io (Ar …

PIA01104

Jupiter

Solid-State Imaging

Title	Geologic Landforms on Io (Area 2)
Original Caption Released with Image	Shown here is one of the topographic mapping images of Jupiter's moon Io (Latitude: +5 to +48 degrees, Longitude: 120 to 185 degrees) acquired by NASA's Galileo spacecraft, revealing a great variety of landforms. There are rugged mountains several miles high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. There are also dark lava flows and bright deposits of SO2 frost or other sulfurous materials, which have no discernable topographic relief at this scale. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. North is to the top of the picture and the sun illuminates the surface from the left. The bright region beyond Io's limb (upper right corner) is Jupiter's atmosphere. The image covers an area about 2080 kilometers wide and the smallest features that can be discerned are 2.6 kilometers in size. This image was taken on November 6th, 1996, at a range of 258,100 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Geologic Landforms on Io (Ar …

PIA01107

Jupiter

Solid-State Imaging

Title	Geologic Landforms on Io (Area 5)
Original Caption Released with Image	Shown here is one of the topographic mapping images of Jupiter's moon Io (Latitude: -40 to +90 degrees, Longitude: 210-320 degrees) acquired by NASA's Galileo spacecraft, revealing a great variety of landforms. There are rugged mountains several miles high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. There are also dark lava flows and bright deposits of SO2 frost or other sulfurous materials, which have no discernable topographic relief at this scale. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. The volcano Ra Patera, seen to have an active plume 75 km high during Galileo's first orbit in June 1996, is located on the bright limb of this image but no plume can be seen, so it is now (5 months later) inactive. North is to the top of the picture and the sun illuminates the surface from the left. The image covers an area about 2800 kilometers wide and the smallest features that can be discerned are 4.1 kilometers in size. This image was taken on November 6th, 1996, at a range of 403,100 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

High Resolution Mosaic of Ridges, Plains, and Mountains on Europa

High Resolution Mosaic of Ri …

PIA01126

Jupiter

Solid-State Imaging

Title	High Resolution Mosaic of Ridges, Plains, and Mountains on Europa
Original Caption Released with Image	This mosaic shows some of the highest resolution images obtained by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its eleventh orbit around Jupiter. North is to the top of the image. The sun illuminates the scene from the left, showing hundreds of ridges that cut across each other, indicating multiple episodes of ridge formation either by volcanic or tectonic activity within the ice. Also visible in the image are numerous isolated mountains or "massifs". The highest of these, located in the upper right corner and lower center of the mosaic, are approximately 500 meters (1,640 feet) high. Irregularly shaped areas where the ice surface appears to be lower than the surrounding plains (e.g., in the left-center and lower left corner of the mosaic) may be related to the "chaos" areas of iceberg-like features seen in earlier SSI images of Europa. The mosaic, centered at 35.4 degrees north latitude and 86.8 degrees west longitude, covers an area of 108 kilometers by 90 kilometers (66 miles by 55 miles). The smallest distinguishable features in the image are about 68 meters (223 feet) across. These images were obtained on November 6, 1997, when the Galileo spacecraft was approximately 3,250 kilometers (1,983 miles) from Europa. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of California Institute of Technology. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Europa - Ice Rafting View

PIA01127

Jupiter

Solid-State Imaging

Title	Europa - Ice Rafting View
Original Caption Released with Image	View of a small region of the thin, disrupted, ice crust in the Conamara region of Jupiter's moon Europa showing the interplay of surface color with ice structures. The white and blue colors outline areas that have been blanketed by a fine dust of ice particles ejected at the time of formation of the large (26 kilometer in diameter) crater Pwyll [ http://photojournal.jpl.nasa.gov/catalog/PIA01211 ] some 1000 kilometers to the south. A few small craters of less than 500 meters or 547 yards in diameter can be seen associated with these regions. These were probably formed, at the same time as the blanketing occurred, by large, intact, blocks of ice thrown up in the impact explosion that formed Pwyll. The unblanketed surface has a reddish brown color that has been painted by mineral contaminants carried and spread by water vapor released from below the crust when it was disrupted. The original color of the icy surface was probably a deep blue color seen in large areas elsewhere on the moon. The colors in this picture have been enhanced for visibility. North is to the top of the picture and the sun illuminates the surface from the right. The image, centered at 9 degrees north latitude and 274 degrees west longitude, covers an area approximately 70 by 30 kilometers (44 by 19 miles), and combines data taken by the Solid State Imaging (CCD) system on NASA's Galileo spacecraft during three of its orbits through the Jovian system. Low resolution color (violet, green, and infrared) data acquired in September 1996, were combined with medium resolution images from December 1996, to produce synthetic color images. These were then combined with a high resolution mosaic of images [ http://photojournal.jpl.nasa.gov/catalog/PIA00591 ] acquired on February 20th, 1997 at a resolution of 54 meters (59 yards) per picture element and at a range of 5340 kilometers (3320 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of California Institute of Technology (Caltech). This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Mosaic of Io

PIA01108

Jupiter

Solid-State Imaging

Title	Mosaic of Io
Original Caption Released with Image	Mosaic of images of Io acquired during orbit C3, showing more than half of Io's surface. These are the best images available to show topographic features over most of this region. The map projection is called Simple Cylindrical, and the grid lines mark 10 degree intervals of latitude and longitude. The mosaic covers an area of about 8 million square kilometers, and the finest details that can discerned are about 2.5 kilometers in size. North is to the top of the picture and the sun illuminates the surface from the left. The images which form this mosaic were obtained through the clear filter of the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft on Nov. 6, 1996 (Universal Time) at a range which varied from 245,719 kilometers to 403,100 kilometers. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Io imaging during Galileo's …

PIA01605

Jupiter

Title	Io imaging during Galileo's 24th orbit
Original Caption Released with Image	During its 14th orbit of Jupiter in March 29, 1998, NASA's Galileo spacecraft captured an image of Jupiter's moon, Io, that has the same lighting geometry that will exist during Io's close Io flyby on October 11, 1999 (the 24th orbit). The spacecraft groundtrack on Io is shown, with two-minute intervals marked by X's. The large X marks the location of closest approach, when Galileo will be just 500 kilometers (about 300 miles) above Io's surface. The curved boundary on the left marks the "terminator" or boundary between the lit day side and dark night side. Although the Pele volcano will be on the night side during the flyby, the hot lavas will be seen glowing in the dark. Other targets of interest that will be visible near closest approach are Pillan Patera, the site of dramatic surface changes [ http://photojournal.jpl.nasa.gov/catalog/PIA00744 ], Reiden Patera, Marduk, the bright plains of Colchis regio, and the rugged Dorian Montes mountains. Active volcanic plumes and high-temperature hot spots have been seen at Pele, Pillan, and Marduk. North is to the top of this image, which has a resolution of 2.6 kilometers (1.6 miles) per picture element. The image was taken at a range of 256,948 kilometers (about 160,000 miles) by the solid state imaging camera system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the World Wide Web on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] . Background information and educational context for the images can be found at http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] .

Venus as Viewed Through Violet and Near Infrared Filters

Venus as Viewed Through Viol …

PIA00073

Sol (our sun)

Solid-State Imaging

Title	Venus as Viewed Through Violet and Near Infrared Filters
Original Caption Released with Image	These two Galileo images of Venus show the global structure of cloud patterns at two different depths in the upper cloud layers. The large bluish image, taken through the violet filter, shows patterns at the very top of Venus' main sulfuric acid haze layer. The subsolar point is to the right, not far from the limb, the atmospheric flow runs to the left from there. The small red image, taken through a near infrared filter, shows the cloud patterns several miles below the visible cloud tops. The colors shown are artificial, the images were enhanced at the National Optical Astronomy Observatories, Tucson, Arizona. The Galileo Project is managed for NASA by the Jet Propulsion Laboratory.

Volcanically Active Regions …

PIA00537

Jupiter

Solid-State Imaging

Title	Volcanically Active Regions on Io
Original Caption Released with Image	Shown here is a portion of one of the highest-resolution images of Io (Latitude: +10 to +60 degrees, Longitude: 180 to 225 degrees) acquired by the Galileo spacecraft, revealing immense lava flows and other volcanic landforms. Several high-temperature volcanic hot spots have been detected in this region by both the Near Infrared Mapping Spectrometer and the imaging system of Galileo. The temperatures are consistent with active silicate volcanism in lava flows or lava lakes (which reside inside irregular depressions called calderas). The large dark lava flow in the upper left region of the image is more than 400 km long, similar to ancient flood basalts on Earth and mare lavas on the Moon. North is to the top of the picture and the sun illuminates the surface from the left. The image covers an area 1230 kilometers wide and the smallest features that can be discerned are 2.5 kilometers in size. This image was taken on November 6th, 1996, at a range of 245,719 kilometers by the Solid State Imaging (CCD) system on the Galileo Spacecraft. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

Tall Mountain, Tohil Mons, o …

PIA03600

Jupiter

Solid-State Imaging

Title	Tall Mountain, Tohil Mons, on Io
Original Caption Released with Image	Dramatic shadows across a mountainous landscape on Jupiter's moon Io reveal details of the topography around a peak named Tohil Mons in this mosaic created from images taken by NASA's Galileo spacecraft in October 2001. Tohil Mons rises 5.4 kilometers (18,000 feet) above Io's surface, according to analysis of stereo imaging [ http://photojournal.jpl.nasa.gov/catalog/PIA02586 ] from earlier Galileo flybys of Io. The new images, with a resolution of 327 meters (1,070 feet) per picture element, were taken when the Sun was low in the sky, producing informative shadows. North is to the top and the Sun illuminates the surface from the upper right. The topographic features revealed include a very straight ridge extending southwest from the peak, 500- to 850-meter-high (1,640- to 2,790-foot-high) cliffs to the northwest and a curious pit immediately east of the peak. Major questions remain about how Io's mountains form and how they are related to Io's ubiquitous volcanoes. Although Io is extremely active volcanically, few of its mountains appear to be volcanoes. However, two volcanic craters do lie directly to the northeast of Tohil's peak, a smaller dark-floored one and a larger one at the very edge of the mosaic. Furthermore, the shape of the pit directly east of the peak suggests a volcanic origin. Galileo scientists will use these images to investigate the geologic history of Tohil Mons and its relationship to the neighboring volcanic features. The image is centered at 28 degrees south latitude and 161 degrees west longitude. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about Galileo and its discoveries is available on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ].

Close-up of Europa's Trailing Hemisphere

Close-up of Europa's Trailin …

PIA00587

Jupiter

Solid-State Imaging

Title	Close-up of Europa's Trailing Hemisphere
Original Caption Released with Image	This complex terrain on Jupiter's moon, Europa, shows an area centered at 8 degrees north latitude, 275.4 degrees west longitude, in the trailing hemisphere. As Europa moves in its orbit around Jupiter, the trailing hemisphere is the portion which is always on the moon's backside opposite to its direction of motion. The area shown is about 100 kilometers by 140 kilometers (62 miles by 87 miles). The complex ridge crossing the picture in the upper left corner is part of a feature that can be traced hundreds of miles across the surface of Europa, extending beyond the edge of the picture. The upper right part of the picture shows terrain that has been disrupted by an unknown process, superficially resembling blocks of sea ice during a springtime thaw. Also visible are semicircular mounds surrounded by shallow depressions. These might represent the intrusion of material punching through the surface from below and partial melting of Europa's icy crust. The resolution of this image is about 180 meters (200 yards), this means that the smallest visible object is about a quarter of a mile across. This picture of Europa was taken by Galileo's Solid State Imaging system from a distance of 17,900 kilometers (11,100 miles) on the spacecraft's sixth orbit around Jupiter, on February 20, 1997. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at http://galileo.jpl.nasa.gov.

Jupiter's Icy Satellite Euro …

PIA00539

Jupiter

Solid-State Imaging

Title	Jupiter's Icy Satellite Europa
Original Caption Released with Image	This image of Europa, an icy satellite of Jupiter, was obtained from a range of 39028 miles (62089 kilometers) by the Galileo spacecraft during its fourth orbit around Jupiter and its first close pass of Europa. The image spans an area 157 miles by 244 miles (252 km by 393 km), and shows features as small as a mile (1.6 km) across. Sun illumination is from the right, revealing several ridges crossing the scene, plateaus commonly several miles (10 km) across, and patches of smooth, low-lying darker materials. No prominent impact craters are visible, indicating the surface in this location is not geologically ancient. Some ridges have gaps, and subtle textural differences in these areas indicate that missing ridge segments probably were swept away by volcanic flows. The flow deposits are probably composed mainly of water ice, the chief constituent of the surface of Europa. The Galileo mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. This image and other images and data received from Galileo are posted on the Galileo mission home page on the World Wide Web at http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ]. Background information and educational context for the images can be found at http://www2.jpl.nasa.gov/galileo/sepo/ [ http://www2.jpl.nasa.gov/galileo/sepo/ ].

Europa Ice Rafts

PIA00591

Jupiter

Solid-State Imaging

Title	Europa Ice Rafts
Original Caption Released with Image	This high resolution image shows the ice-rich crust of Europa, one of the moons of Jupiter. Seen here are crustal plates ranging up to 13 kilometers (8 miles) across, which have been broken apart and "rafted" into new positions, superficially resembling the disruption of pack-ice on polar seas during spring thaws on Earth. The size and geometry of these features suggest that motion was enabled by ice-crusted water or soft ice close to the surface at the time of disruption. The area shown is about 34 kilometers by 42 kilometers (21 miles by 26 miles), centered at 9.4 degrees north latitude, 274 degrees west longitude, and the resolution is 54 meters (59 yards). This picture was taken by the Solid State Imaging system on board the Galileo spacecraft on February 20, 1997, from a distance of 5,340 kilometers (3,320 miles) during the spacecraft's close flyby of Europa. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at: http://galileo.jpl.nasa.gov.

Close-up of Europa's Surface

PIA00592

Jupiter

Solid-State Imaging

Title	Close-up of Europa's Surface
Original Caption Released with Image	This close-up view of the icy surface of Europa, a moon of Jupiter, was obtained on December 20, 1996, by the Solid State Imaging system on board the Galileo spacecraft during its fourth orbit around Jupiter. The view is about 11 kilometers by 16 kilometers (7 miles by 10 miles) and has a resolution of 26 meters (28 yards). The Sun illuminates the scene from the east (right). A flat smooth area about 3.2 kilometers (2 miles) across is seen in the left part of the picture. This area resulted from flooding by a fluid which erupted onto the surface and buried sets of ridges and grooves. The smooth area contrasts with a distinctly rugged patch of terrain farther east, to the right of the prominent ridge system running down the middle of the picture. The rugged patch of terrain is 4 kilometers (2.5 miles) across and represents localized disruption of the complex network of ridges in the area. Eruptions of material onto the surface, crustal disruption, and the formation of complex networks of folded and faulted ridges show that significant energy was available in the interior of Europa. Although small impact craters are most easily seen in the smooth area, they occur throughout the ridged terrain seen in this view. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at: http://galileo.jpl.nasa.gov.

Europa Triple Band

PIA00590

Jupiter

Solid-State Imaging

Title	Europa Triple Band
Original Caption Released with Image	This picture of Europa, a moon of Jupiter, was obtained on February 20, 1997, by the Solid State Imaging system onboard the Galileo spacecraft during its sixth orbit around Jupiter. The area is centered at 9.3 degrees north latitude, 275.7 degrees west longitude, on the trailing hemisphere of Europa. As Europa moves in its orbit around Jupiter, the trailing hemisphere is the portion which is always on the moon's backside opposite to its direction of motion. The area depicted is about 32 kilometers by 40 kilometers (20 miles by 25 miles). Resolution is 54 meters (59 yards). The Sun illuminates the scene from the right (east). A section of a triple band crosses the upper left of the picture and extends for hundreds of miles across the surface. Triple bands derive their name from their appearance at lower resolution as a narrow bright band flanked by a pair of darker bands. At the high resolution of this picture, however, the triple band is much more complex and is composed of a system of ridges 6 kilometers (4 miles) across. Some ridges reach heights of about 180 meters (200 yards). Other features include a hill in the center of the picture about 480 meters (500 yards) high. Two mounds about 6 kilometers across (4 miles) are seen in the bottom of the picture. The ridges, hills and mounds probably all represent uplifts of the icy crust of Europa by processes originating from the interior. The Jet Propulsion Laboratory, Pasadena, CA, manages the mission for NASA's Office of Space Science, Washington D.C. This image and other images and data received from Galileo are posted on the World Wide Web Galileo mission home page at: http://galileo.jpl.nasa.gov.

High Resolution Global View …

PIA00583

Jupiter

Solid-State Imaging

Title	High Resolution Global View of Io
Original Caption Released with Image	Io, the most volcanic body in the solar system is seen in the highest resolution obtained to date by NASA's Galileo spacecraft. The smallest features that can be discerned are 2.5 kilometers in size. There are rugged mountains several kilometers high, layered materials forming plateaus, and many irregular depressions called volcanic calderas. Several of the dark, flow-like features correspond to hot spots, and may be active lava flows. There are no landforms resembling impact craters, as the volcanism covers the surface with new deposits much more rapidly than the flux of comets and asteroids can create large impact craters. The picture is centered on the side of Io that always faces away from Jupiter, north is to the top. Color images acquired on September 7, 1996 have been merged with higher resolution images acquired on November 6, 1996 by the Solid State Imaging (CCD) system aboard NASA's Galileo spacecraft. The color is composed of data taken, at a range of 487,000 kilometers, in the near-infrared, green, and violet filters and has been enhanced to emphasize the extraordinary variations in color and brightness that characterize Io's face. The high resolution images were obtained at ranges which varied from 245,719 kilometers to 403,100 kilometers. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

The Tyre multi-ring Structur …

PIA01633

Jupiter

Solid-State Imaging

Title	The Tyre multi-ring Structure on Europa
Original Caption Released with Image	This mosaic shows the Tyre multi-ring structure which is thought to have been formed by a large impact onto Jupiter's moon Europa. The effective crater (large bull's-eye feature) is about 40 kilometers (25 miles) across while the entire structure is much larger. The feature was formerly known as Tyre Macula. The concentric rings, of which five to seven can be discerned easily, consist of troughs and ridges. Tyre is one of the few impact structures on Europa that has concentric rings and may indicate an area where fluid material, perhaps liquid water, lay below the surface at the time of impact. A few ridges within Tyre appear to have been partly destroyed at the time of impact. North is to the top of the picture and the sun illuminates the surface from the left. The mosaic is centered at 34 degrees north latitude and 144 degrees west longitude and covers an area approximately 424 by 456 kilometers (265 by 285 miles). The resolution is 170 meters (185 feet) across. The horizontal and vertical black lines in the mosaic indicate gaps in the data received for this image. The images were taken on March 29, 1998 at a range of approximately 18,000 kilometers (11,250 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission or NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]

Narrow Search

Remove

What

Where

When

Browse All : Galileo Orbiter of Arizona