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View of Callisto at Increasi
…
PIA01297
Jupiter
Solid-State Imaging
| Title |
View of Callisto at Increasing Resolutions |
| Original Caption Released with Image |
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, These four views of Jupiter's second largest moon, Callisto, highlight how increasing resolutions enable interpretation of the surface. In the global view (top left) the surface is seen to have many small bright spots, while the regional view (top right) reveals the spots to be the larger craters. The local view (bottom right) not only brings out smaller craters and detailed structure of larger craters, but also shows a smooth dark layer of material that appears to cover much of the surface. The close-up frame (bottom left) presents a surprising smoothness in this highest resolution (30 meters per picture element) view of Callisto's surface. North is to the top of these frames which were taken by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft between November 1996 and November 1997. Even higher resolution images (better than 20 meters per picture element) of Callisto will be taken on June 30, 1999 during the 21st orbit of the spacecraft around Jupiter. The top left frame is scaled to 10 kilometers (km) per picture element (pixel) and covers an area about 4400 by 2500 km. The moon Callisto, which has a diameter of 4806 km, appears to be peppered with many bright spots. Images at this resolution of other cratered moons in the Solar System indicate that the bright spots could be impact craters. The ring structure of Valhalla, the largest impact structure on Callisto, is visible in the center of the frame. This color view combines images obtained in November 1997 taken through the green, violet, and 1 micrometer filters of the SSI system. The top right frame is ten times higher resolution (about 1 km per pixel) and covers an area approximately 440 by 250 km. Craters, which are clearly recognizable, appear to be the dominant landform on Callisto. The crater rims appear bright, while the adjacent area and the crater interiors are dark. This resolution is comparable to the best data available from the 1979 flyby's of NASA's two Voyager spacecraft, it reflects the understanding of Callisto prior to new data from Galileo. This Galileo image was taken in November 1996. The resolution of the bottom right image is again ten times better (100 meters per pixel) and covering an area of about 44 by 25 km. This resolution reveals that some crater rims are not complete rings, but are composed of bright isolated segments. Steep slopes near crater rims reveal dark material that appears to have slid down to reveal bright material. The thickness of the dark layer could be tens of meters. The image was taken in June 1997. The bottom left image at about 29 meters per pixel is the highest resolution available for Callisto. It covers an area about 4.4 by 2.5 km and is somewhat oblique. Craters are visible but no longer dominate the surface. The image was taken in November 1996. 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 |
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Active Volcanic Plumes on Io
PIA00703
Jupiter
Solid-State Imaging
| Title |
Active Volcanic Plumes on Io |
| Original Caption Released with Image |
This color image, acquired during Galileo's ninth orbit around Jupiter, shows two volcanic plumes on Io. One plume was captured on the bright limb or edge of the moon (see inset at upper right), erupting over a caldera (volcanic depression) named Pillan Patera after a South American god of thunder, fire and volcanoes. The plume seen by Galileo is 140 kilometers (86 miles) high and was also detected by the Hubble Space Telescope. The Galileo spacecraft will pass almost directly over Pillan Patera in 1999 at a range of only 600 kilometers (373 miles). The second plume, seen near the terminator (boundary between day and night), is called Prometheus after the Greek fire god (see inset at lower right). The shadow of the 75-kilometer (45- mile) high airborne plume can be seen extending to the right of the eruption vent. The vent is near the center of the bright and dark rings. Plumes on Io have a blue color, so the plume shadow is reddish. The Prometheus plume can be seen in every Galileo image with the appropriate geometry, as well as every such Voyager image acquired in 1979. It is possible that this plume has been continuously active for more than 18 years. In contrast, a plume has never been seen at Pillan Patera prior to the recent Galileo and Hubble Space Telescope images. North is toward the top of the picture. The resolution is about 6 kilometers (3.7 miles) per picture element. This composite uses images taken with the green, violet and near infrared filters of the solid state imaging (CCD) system on NASA's Galileo spacecraft. The images were obtained on June 28, 1997, at a range of more than 600,000 kilometers (372,000 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 |
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Io imaging during Galileo's
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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 ] . |
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A New Hot Spot on Northern I
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PIA03602
Jupiter
Near Infrared Mapping Spectr
…
| Title |
A New Hot Spot on Northern Io |
| Original Caption Released with Image |
NASA's Galileo spacecraft has returned infrared imagery of a new hot spot on Jupiter's moon Io that was the source of a towering plume in August 2001, indicating a sulfur-dioxide concentration that may have been fallout from the plume. Galileo's near-infrared mapping spectrometer captured the image on the left during an Oct. 16, 2001 flyby of Io. Coloring indicates the intensity of glowing at a wavelength of 4.1 microns. Yellow, red, and white represent high temperatures. Black is where the near-infrared glow was so intense the image was saturated. Greens and blues are cold. The visible-light image on the right was obtained by Galileo's camera in 1999, before any volcanic activity was seen at this site. The first sign of activity came in August 2001, when Galileo detected an infrared hot spot and the tallest volcanic plume ever seen at Io. The dark blue band north of the hot spot in the new infrared image represents a concentration of sulfur-dioxide, which has a strong signature in the infrared. The sulfur-dioxide is thought to be from the fallout of the plume. The image shows high temperatures corresponding to yellow flows in the center of the visible-light image, and from a small caldera at the 8 o'lock position. 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 ]. |
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Potential Source of Sulfur F
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PIA03887
Jupiter
Solid-State Imaging
| Title |
Potential Source of Sulfur Flow on Io |
| Original Caption Released with Image |
A field of bright lava flows next to a shield volcano could be a source of recent sulfur volcanism on Io, as detected by instruments aboard NASA's Galileo spacecraft. The mosaic at left combines higher-resolution images (330 meters or about 1080 feet per picture element) taken in October 2001 with lower-resolution color images (1.4 kilometers or 0.9 mile per picture element) taken in July 1999 by Galileo's solid-state imaging camera. By comparing these images with a map of hot spots taken in February by Galileo's near-infrared mapping spectrometer (lower right), Galileo scientists noted that a new hot spot west of the active volcano Prometheus became bright in February 2000 and dimmed later. This hot spot appears to correspond with the bright flow field just west of a recently discovered shield volcano (see PIA03532 [ http://photojournal.jpl.nasa.gov/catalog/PIA03532 ]), which is the only fresh volcanic material in the area. The relatively low intensity of the February 2000 hot spot in the infrared data suggests a low-temperature eruption, consistent with sulfur lava rather than silicate lava as found elsewhere on Io and also on Earth. Sulfur lavas are thought to cool to a gray-yellow color on Io, as seen in the new flow field visible in the camera image. This bright flow field could be the best example of active sulfur lava flows deposited on Io during the Galileo mission. At upper right is a global view of Io showing the location of the more-detailed images. The low temperature of this hot spot differs from many of Io's other active volcanoes, such as Pele, Tvashtar and Prometheus. Intense tidal flexing of Io helps keep the moon's interior molten, at some places producing silicate lavas hotter than any seen on Earth in billions of years. Io has the greatest known diversity of volcanic activity in the solar system. North is to the top of all these images. 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 ]. |
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Io's Culann-Tohil Region in
…
PIA03885
Jupiter
Solid-State Imaging
| Title |
Io's Culann-Tohil Region in Color |
| Original Caption Released with Image |
North is to the top of all images. 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 ]., Repeated flybys of Io by NASA's Galileo spacecraft have allowed scientists to develop an understanding of Io's Tohil-Culann region of interconnected volcanoes and mountains. An active volcano named Culann Patera (top center) is one of the most colorful volcanoes on Jupiter's innermost large moon (see PIA02535 [ http://photojournal.jpl.nasa.gov/catalog/PIA02535 ]). It lies just north of an enigmatic mountain called Tohil Mons (see PIA03600 [ http://photojournal.jpl.nasa.gov/catalog/PIA03600 ]). This mosaic image uses high-resolution Galileo images of Culann (200 meters or 660 feet per picture element) from the November 1999 flyby and high-resolution images of Tohil (165 meters or 540 feet per picture element) from the February 2000 flyby, and combines them with lower-resolution color images (1.4 kilometers or 0.9 mile per picture element) taken during the July 1999 flyby. Using the combined information, Galileo scientists have identified relationships among many colorful features in this complex. The volcano Culann has produced both dark black and dark red lava flows, as well as diffuse, inner and outer rings of red and yellowish sulfur particles from explosive plumes (for example, PIA02502 [ http://photojournal.jpl.nasa.gov/catalog/PIA02502 ]). Molten silicate rock inside Culann must occasionally mix with subsurface reservoirs of sulfur and sulfur dioxide to produce the plume deposits. The green color at the center of Culann and inside the older volcano Tohil Patera (center right) forms when red sulfur plume deposits land on dark black silicate lava flows and form a green veneer. The large white patch in southwestern Tohil Patera is rich in sulfur dioxide, and comparison with higher-resolution views (for example, PIA03527 [ http://photojournal.jpl.nasa.gov/catalog/PIA03527 ]) suggests that this might be a region of cold sulfur dioxide flows. The small white patches on the mountain Tohil Mons might be deposits of sulfur dioxide snow that accumulate in grooves and at the bases of steep slopes in colder areas on the mountain. At upper right is a global view of Io showing the location of the mosaic. Although Tohil Mons rises up to 6 kilometers (19,700 feet) above Io's plains, it is difficult to see in this image because the Sun was behind Galileo at the time it was taken. The topography of the mountainous region is clearer in a mosaic of images taken when the Sun was low in the sky, with illumination from the right (see figure below) The side-lit mosaic combines a high-resolution (330 meters or 1,100 feet per picture element) image from October 2001 with lower-resolution color images (1.4 kilometers or 0.9 mile per picture element) from July 1999. |
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Io's Culann-Tohil Region in
…
PIA03885
Jupiter
Solid-State Imaging
| Title |
Io's Culann-Tohil Region in Color |
| Original Caption Released with Image |
North is to the top of all images. 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 ]., Repeated flybys of Io by NASA's Galileo spacecraft have allowed scientists to develop an understanding of Io's Tohil-Culann region of interconnected volcanoes and mountains. An active volcano named Culann Patera (top center) is one of the most colorful volcanoes on Jupiter's innermost large moon (see PIA02535 [ http://photojournal.jpl.nasa.gov/catalog/PIA02535 ]). It lies just north of an enigmatic mountain called Tohil Mons (see PIA03600 [ http://photojournal.jpl.nasa.gov/catalog/PIA03600 ]). This mosaic image uses high-resolution Galileo images of Culann (200 meters or 660 feet per picture element) from the November 1999 flyby and high-resolution images of Tohil (165 meters or 540 feet per picture element) from the February 2000 flyby, and combines them with lower-resolution color images (1.4 kilometers or 0.9 mile per picture element) taken during the July 1999 flyby. Using the combined information, Galileo scientists have identified relationships among many colorful features in this complex. The volcano Culann has produced both dark black and dark red lava flows, as well as diffuse, inner and outer rings of red and yellowish sulfur particles from explosive plumes (for example, PIA02502 [ http://photojournal.jpl.nasa.gov/catalog/PIA02502 ]). Molten silicate rock inside Culann must occasionally mix with subsurface reservoirs of sulfur and sulfur dioxide to produce the plume deposits. The green color at the center of Culann and inside the older volcano Tohil Patera (center right) forms when red sulfur plume deposits land on dark black silicate lava flows and form a green veneer. The large white patch in southwestern Tohil Patera is rich in sulfur dioxide, and comparison with higher-resolution views (for example, PIA03527 [ http://photojournal.jpl.nasa.gov/catalog/PIA03527 ]) suggests that this might be a region of cold sulfur dioxide flows. The small white patches on the mountain Tohil Mons might be deposits of sulfur dioxide snow that accumulate in grooves and at the bases of steep slopes in colder areas on the mountain. At upper right is a global view of Io showing the location of the mosaic. Although Tohil Mons rises up to 6 kilometers (19,700 feet) above Io's plains, it is difficult to see in this image because the Sun was behind Galileo at the time it was taken. The topography of the mountainous region is clearer in a mosaic of images taken when the Sun was low in the sky, with illumination from the right (see figure below) The side-lit mosaic combines a high-resolution (330 meters or 1,100 feet per picture element) image from October 2001 with lower-resolution color images (1.4 kilometers or 0.9 mile per picture element) from July 1999. |
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Recent Eruption at Gish Bar
…
PIA03884
Jupiter
Solid-State Imaging
| Title |
Recent Eruption at Gish Bar Patera on Io |
| Original Caption Released with Image |
This image taken by NASA's Galileo spacecraft reveals fresh lava in a wide pit named Gish Bar Patera on Jupiter's moon Io. The patera, or depression, is quite large: 106.3 kilometers (66 miles) by 115.0 kilometers (71 miles). Galileo has detected volcanic activity at this site in the past, particularly in late 1996. Galileo took this image on Oct. 16, 2001, during its 32nd orbit of Jupiter. Effects of a new eruption at Gish Bar can be seen in a comparison with images from 1999 (see figure below). The new eruption was first detected in infrared imaging by Galileo's near-infrared mapping spectrometer in August 2001. This visible-light image shows a pair of new lava flows. The largest runs to the western boundary and extends to the central and northern portions of the patera. The other flow corresponds to a secondary depression in the southeastern portion of the patera. Based on changes seen at this depression between July and October 1999, this is thought to be the site of an outburst seen by Earth-based observers in August 1999. Gish Bar Patera lies at the base of an 11-kilometer (36,000-foot) mountain at 15.6 degrees north latitude, 89.1 degrees west longitude on Io. This image was taken from a distance of 25,000 kilometers (15,500 miles) and has a resolution of 250 meters (820 feet) per pixel. The Sun is straight behind the observer, an illumination angle that minimizes shadows and emphasizes inherent brightness variations rather than topography. 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 ]. |
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Recent Eruption at Gish Bar
…
PIA03884
Jupiter
Solid-State Imaging
| Title |
Recent Eruption at Gish Bar Patera on Io |
| Original Caption Released with Image |
This image taken by NASA's Galileo spacecraft reveals fresh lava in a wide pit named Gish Bar Patera on Jupiter's moon Io. The patera, or depression, is quite large: 106.3 kilometers (66 miles) by 115.0 kilometers (71 miles). Galileo has detected volcanic activity at this site in the past, particularly in late 1996. Galileo took this image on Oct. 16, 2001, during its 32nd orbit of Jupiter. Effects of a new eruption at Gish Bar can be seen in a comparison with images from 1999 (see figure below). The new eruption was first detected in infrared imaging by Galileo's near-infrared mapping spectrometer in August 2001. This visible-light image shows a pair of new lava flows. The largest runs to the western boundary and extends to the central and northern portions of the patera. The other flow corresponds to a secondary depression in the southeastern portion of the patera. Based on changes seen at this depression between July and October 1999, this is thought to be the site of an outburst seen by Earth-based observers in August 1999. Gish Bar Patera lies at the base of an 11-kilometer (36,000-foot) mountain at 15.6 degrees north latitude, 89.1 degrees west longitude on Io. This image was taken from a distance of 25,000 kilometers (15,500 miles) and has a resolution of 250 meters (820 feet) per pixel. The Sun is straight behind the observer, an illumination angle that minimizes shadows and emphasizes inherent brightness variations rather than topography. 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 ]. |
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Galileo's Last View of Tvash
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PIA03529
Jupiter
Solid-State Imaging
| Title |
Galileo's Last View of Tvashtar, Io |
| Original Caption Released with Image |
This mosaic of Tvashtar Catena on Jupiter's moon Io, taken by NASA's Galileo spacecraft on Oct. 16, 2001, completes a series of views depicting changes in the region over a period of nearly two years. A catena is a chain of volcanic craters. Streaks of light and dark deposits that radiate from the central volcanic crater, or "patera," are remnants of a tall plume that was seen erupting in earlier images. This image and the others from November 1999, February 2000 [ http://photojournal.jpl.nasa.gov/catalog/PIA02584 ], December 2000 [ http://photojournal.jpl.nasa.gov/catalog/PIA02588 ], and August 2001 [ http://photojournal.jpl.nasa.gov/catalog/PIA02592 ] were all taken to study aspects of this ever-changing, extremely active volcanic field. Tvashtar is pictured here just 10 months after both the Galileo and Cassini spacecraft observed the eruption of a giant plume of volcanic gas emanating from it. The plume rose 385 kilometers (239 miles) high and blanketed terrain as far as 700 kilometers (435 miles) from its center. Tvashtar has erupted in a variety of styles over the course of almost two years: (1) a lava curtain [ http://photojournal.jpl.nasa.gov/catalog/PIA02519 ] 50 kilometers (30 miles) long in the center patera, (2) a giant lava flow or lava lake eruption [ http://photojournal.jpl.nasa.gov/catalog/PIA02550 ] in the giant patera at far left, and (3) the large plume eruption [ http://photojournal.jpl.nasa.gov/catalog/PIA02588 ]. Therefore Galileo scientists expected that the lava flow margins or patera boundaries within Tvashtar would have changed drastically. However, the series of observations revealed little modification of this sort, suggesting that the intense eruptions at Tvashtar are confined by the local topography. North is to the top of the mosaic, which is approximately 300 kilometers(186 miles) across and has a resolution of 200 meters (656 feet) per picture element. 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 athttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educationalcontext for the images can be found at http://galileo.jpl.nasa.gov/gallery/io.cfm [ http://galileo.jpl.nasa.gov/gallery/io.cfm ]. |
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Color Mosaic and Active Volc
…
PIA01081
Jupiter
Solid-State Imaging
| Title |
Color Mosaic and Active Volcanic Plumes on Io |
| Original Caption Released with Image |
This color image, acquired during Galileo's ninth orbit (C9) around Jupiter, shows two volcanic plumes on Io. One plume was captured on the bright limb or edge of the moon, erupting over a caldera (volcanic depression) named Pillan Patera. The plume seen by Galileo is 140 kilometers (86 miles) high, and was also detected by the Hubble Space Telescope. The Galileo spacecraft will pass almost directly over Pillan Patera in 1999 at a range of only 600 (373 miles). The second plume, seen near the terminator, the boundary between day and night, is called Prometheus after the Greek fire god). The shadow of the airborne plume can be seen extending to the right of the eruption vent. (The vent is near the center of the bright and dark rings). Plumes on Io have a blue color, so the plume shadow is reddish. The Prometheus plume can be seen in every Galileo image with the appropriate geometry, as well as every such Voyager image acquired in 1979. It is possible that this plume has been continuously active for more than 18 years. In contrast, a plume has never been seen at Pillan Patera prior to the recent Galileo and HST images.Color images from orbit C9 have been merged with a high resolution mosaic of images acquired in various orbits to enhance the surface detail. PIA00703 [ http://photojournal.jpl.nasa.gov/catalog/PIA00703 ] is another version of this image which also includes detailed insets of the plumes. North is to the top of the picture. The resolution is about 2 kilometers (1.2 miles) per picture element. This composite uses images taken with the green, violet, and near-infrared filters of the Solid State Imaging (CCD) system on NASA's Galileo spacecraft. The C9 images were obtained on June 28, 1997 at a range of more than 600,000 kilometers (372, 000 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. |
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NIMS Observes the Structure
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PIA01224
Sol (our sun)
Near Infrared Mapping Spectr
…
| Title |
NIMS Observes the Structure and Composition of Jupiter's Clouds |
| Original Caption Released with Image |
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., With the NIMS instrument high quality observations are being obtained from all parts of Jupiter. The images in the upper panel are taken at a wavelength of 4.8 microns. At this wavelength thermal radiation from about 100 km deep below the visible cloud deck is escaping, allowing us to study the deep atmospheric region. The overlying cloud deck absorbs a part of the radiation, but there are places where it is thin and more radiation can escape. These are called hot spot regions. Many hotspots regions occur in a zone between the equator and 15 degrees north latitude, the North Equatorial Belt (NEB), but thermal radiation is seen from much of the planet. The uniqueness of NIMS is that it is capable of observing the same spatial region at a maximum of 408 different wavelengths between 0.7 and 5.2 micron simultaneously. Every picture element (pixel) contains a spectrum of up to 408 wavelengths. The gases that compose the atmosphere leave there traces in the spectra. In this particular case, 48 wavelengths were available between 4.6 and 5.2 micron, and we see spectral signatures of water, ammonia, and phosphine. Also, the total amount of radiation is determined by the amount of overlying cloud, characterized by the cloud opacity. By means of model calculations, we can determine the amount of water and the cloud opacity for each individual spectrum. The amount ammonia and phosphine is more difficult to obtain because its influence on the spectra is weaker. The results of these calculations are shown in the form of maps in the next two panels. With NIMS, we can now have a detailed look at the spatial distribution of the water and ammonia amounts and the cloud opacity in the atmosphere. Not all the pixels from the observations have good spectra, so for some data points no reliable determination of the water and cloud opacity could be made. We find that the atmosphere is extremely dry in, and close to, the hot spot, with relative humidities between 0.02 % and 10 %, with the dryest places being inside the hot spot. This corroborates the in-situ Galileo Entry Probe measurements. The Probe entered the atmosphere, on December 5 1995, in a hot spot region. Whereas the Probe obtained only a very localized snapshot, with NIMS we can do observations of larger areas and over longer periods. The spatial distribution of water is more complex than expected. More detailed investigations will be necessary to fully understand these results. Future studies will also allow a better understanding of the dynamics of the Jovian atmosphere, since the spatial distribution of water is thought to be a tracer for atmospheric motions under the cloud deck. NIMS will continue to provide excellent and unique data during the Galileo Europa Mission, planned to last until December 1999. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's |
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Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
|
Global image of Io (false co
…
PIA02309
Jupiter
Solid-State Imaging
| Title |
Global image of Io (false color) |
| Original Caption Released with Image |
http://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera which have been processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A true color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02308 ] of the mosaic has been created to show how Io would appear to the human eye. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout locations), (Cutout A). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found at URL |
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Global image of Io (true col
…
PIA02308
Jupiter
Solid-State Imaging
| Title |
Global image of Io (true color) |
| Original Caption Released with Image |
. 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 ]., NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's moon Io on 3 July 1999 during its closest pass to Io since orbit insertion in late 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera and approximates what the human eye would see. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red units near the active volcanic centers. A false color version [ http://photojournal.jpl.nasa.gov/catalog/PIA02309 ] of the mosaic has been created to enhance the contrast of the color variations. The improved resolution reveals small-scale color units which had not been recognized previously and which suggest that the lavas and sulfurous deposits are composed of complex mixtures (Cutout A of false color image). Some of the bright (whitish), high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (Cutout B of false color image). Bright red areas were seen previously only as diffuse deposits. However, they are now seen to exist as both diffuse deposits and sharp linear features like fissures (Cutout C of false color image). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur rather than silicate lava (Cutout D of false color image). In this region bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this image to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to the ongoing volcanic activity. Galileo will make two close passes of Io beginning in October of this year. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture and the sun illuminates the surface from almost directly behind the spacecraft. This illumination geometry is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and the rugged topography over parts of Io. The image is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on 3 July 1999 at a range of about 130,000 kilometers (81,000 miles) by the Solid State Imaging (SSI) system on NASA's Galileo spacecraft during its twenty-first orbit. 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 [ http://galileo.jpl.nasa.gov ] |
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Closeups of Io (false color)
PIA02319
Jupiter
Solid-State Imaging
| Title |
Closeups of Io (false color) |
| Original Caption Released with Image |
NASA's Galileo spacecraft acquired its highest resolution images of Jupiter's volcanic moon Io on July 3, 1999 during its closest pass by Io since it entered orbit around Jupiter in December 1995. This color mosaic uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera, processed to enhance more subtle color variations. Most of Io's surface has pastel colors, punctuated by black, brown, green, orange, and red areas near the active volcanic centers. The improved resolution reveals small-scale color areas which were not recognized previously and which suggest that the lava and sulfurous deposits are composed of complex mixtures (close-up A). Some of the bright, whitish, high-latitude (near the top and bottom) deposits have an ethereal quality like a transparent covering of frost (close-up B). Bright red areas were seen in previous images only as diffuse deposits. However, they now appear as both diffuse deposits and sharp linear features like fissures (close-up C). Some volcanic centers have bright and colorful flows, perhaps due to flows of sulfur (rather than silicate) lava (close-up D). In this region of Io, bright, white material can also be seen to emanate from linear rifts and cliffs. Comparison of this mosaic to previous Galileo images [ http://www.jpl.nasa.gov/galileo/sepo/atjup/io/color.html ] reveals many changes due to ongoing volcanic activity. Galileo is scheduled to make two close passes of Io in October and November. Most of the high-resolution targets for these flybys are seen on the hemisphere shown here. North is to the top of the picture, and the Sun illuminates the surface from almost directly behind the spacecraft. This illumination is good for imaging color variations, but poor for imaging topographic shading. However, some topographic shading can be seen here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and rugged topography over parts of Io. The mosaic is centered at 0.3 degrees north latitude and 137.5 degrees west longitude. The images were taken at a distance of about 130,000 kilometers (81,000 miles) by Galileo's onboard solid state imaging camera. 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 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 ]. |
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Close-up of Zamama, Io (colo
…
PIA02504
Jupiter
Solid-State Imaging
| Title |
Close-up of Zamama, Io (color) |
| Original Caption Released with Image |
A volcano named Zamama on Jupiter's moon Io has recently changed in appearance as seen in this pair of images of Io acquired by NASA's Galileo spacecraft as it approached Io in preparation for a close flyby. The false color images use the near-infrared, green and violet filters (a range greater than the range the human eye can see) of the spacecraft's camera, processed to slightly enhance Io's naturally vibrant colors. The image on the left was acquired in March 1998 during Galileo's 14th orbit and the image on the right was collected in July 1999 during the 21st orbit. The July 1999 images are the highest resolution images of Io taken by Galileo since it entered orbit around Jupiter in December 1995.Zamama formed [ http://photojournal.jpl.nasa.gov/catalog/PIA01071 ], during the time period between the flybys of NASA's Voyager spacecraft in 1979 and Galileo's first images of Io taken in 1996. Based on these images, Galileo scientists suspect that the dark lava is erupting from a crack in the ground. Analysis of combined data from Galileo's camera and its near-infrared mapping spectrometer instrument showed that the lava erupting at Zamama must be hotter than 830 C (1,500 F). Because this too hot to be sulfur, scientists believe the lava may contain silicates. The most dramatic difference between these two images is that the volcanic plume that was active in March 1998 and earlier had stopped erupting by July 1999. The rising core of the umbrella-shaped plume can be seen in the 1998 image as a bluish spot in the center of the dark lava. Dark and bright spokes of material falling away from the core are also visible. When it falls back to the ground, this material makes circular white and yellow deposits around the vent. The white deposits are thought to be composed mostly of sulfur dioxide that left the volcanic vent as a vapor and condensed into a frost as the gases expanded into the near-vacuum of Io's atmosphere. Interestingly, red plume material has only been deposited to the northwest. This might be the result of small pockets of boiling sulfur that produce droplets of red sulfur blown outward by the main plume. Most of the other, more subtle color variations around Zamama are likely to be the result of different lighting conditions that existed when the two images were taken. A high-resolution (20 to 40 meters or 66 to 130 feet per picture element) strip of images across Zamama is planned during Galileo's flyby of Io on October 10, 1999. These images will be useful in determining how lava moves on Io's surface, specifically whether the lava travels in open rivers of lava or in well-insulated lava tubes. The size and shape of features on the lava flows can be used to estimate properties of the lava that will provide vital clues to the still unanswered question about what kind of lava is erupting from Io's volcanoes. North is to the top of the pictures. The images are centered at 17.4 degrees north latitude and 173 degrees west longitude. The image on the left was taken on March 1998 at a range of 294,000 kilometers (183,000 miles) and has a resolution of 3 kilometers (2 miles) per picture element. The Sun illuminates the surface from the right. The image on the right was taken in July 1999 at a distance of about 130,000 kilometers (81,000 miles) and has a resolution of 1.3 kilometers or 0.8 miles per picture element. The Sun illuminates the surface from almost directly behind the spacecraft. The Jet Propulsion Laboratory, Pasadena, CA, manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
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Close-up of Zamama, Io (colo
…
PIA02504
Jupiter
Solid-State Imaging
| Title |
Close-up of Zamama, Io (color) |
| Original Caption Released with Image |
A volcano named Zamama on Jupiter's moon Io has recently changed in appearance as seen in this pair of images of Io acquired by NASA's Galileo spacecraft as it approached Io in preparation for a close flyby. The false color images use the near-infrared, green and violet filters (a range greater than the range the human eye can see) of the spacecraft's camera, processed to slightly enhance Io's naturally vibrant colors. The image on the left was acquired in March 1998 during Galileo's 14th orbit and the image on the right was collected in July 1999 during the 21st orbit. The July 1999 images are the highest resolution images of Io taken by Galileo since it entered orbit around Jupiter in December 1995.Zamama formed [ http://photojournal.jpl.nasa.gov/catalog/PIA01071 ], during the time period between the flybys of NASA's Voyager spacecraft in 1979 and Galileo's first images of Io taken in 1996. Based on these images, Galileo scientists suspect that the dark lava is erupting from a crack in the ground. Analysis of combined data from Galileo's camera and its near-infrared mapping spectrometer instrument showed that the lava erupting at Zamama must be hotter than 830 C (1,500 F). Because this too hot to be sulfur, scientists believe the lava may contain silicates. The most dramatic difference between these two images is that the volcanic plume that was active in March 1998 and earlier had stopped erupting by July 1999. The rising core of the umbrella-shaped plume can be seen in the 1998 image as a bluish spot in the center of the dark lava. Dark and bright spokes of material falling away from the core are also visible. When it falls back to the ground, this material makes circular white and yellow deposits around the vent. The white deposits are thought to be composed mostly of sulfur dioxide that left the volcanic vent as a vapor and condensed into a frost as the gases expanded into the near-vacuum of Io's atmosphere. Interestingly, red plume material has only been deposited to the northwest. This might be the result of small pockets of boiling sulfur that produce droplets of red sulfur blown outward by the main plume. Most of the other, more subtle color variations around Zamama are likely to be the result of different lighting conditions that existed when the two images were taken. A high-resolution (20 to 40 meters or 66 to 130 feet per picture element) strip of images across Zamama is planned during Galileo's flyby of Io on October 10, 1999. These images will be useful in determining how lava moves on Io's surface, specifically whether the lava travels in open rivers of lava or in well-insulated lava tubes. The size and shape of features on the lava flows can be used to estimate properties of the lava that will provide vital clues to the still unanswered question about what kind of lava is erupting from Io's volcanoes. North is to the top of the pictures. The images are centered at 17.4 degrees north latitude and 173 degrees west longitude. The image on the left was taken on March 1998 at a range of 294,000 kilometers (183,000 miles) and has a resolution of 3 kilometers (2 miles) per picture element. The Sun illuminates the surface from the right. The image on the right was taken in July 1999 at a distance of about 130,000 kilometers (81,000 miles) and has a resolution of 1.3 kilometers or 0.8 miles per picture element. The Sun illuminates the surface from almost directly behind the spacecraft. The Jet Propulsion Laboratory, Pasadena, CA, manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
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Changes at Pillan Patera
PIA02501
Jupiter
Solid-State Imaging
| Title |
Changes at Pillan Patera |
| Original Caption Released with Image |
Dramatic changes have occurred at the volcanically active Pillan Patera region of Jupiter's moon Io over the past three years, as seen in this set of three images taken by NASA¹s Galileo spacecraft. The image on the left was taken in April 1997. The middle image shows the same area in September 1997 [ http://photojournal.jpl.nasa.gov/catalog/PIA01667 ], after a huge eruption occurred. The eruption produced the large, dark deposit just above and to the right of the center. The deposit, which is 400 kilometers (250 miles) in diameter, surrounds Pillan Patera and covers part of the bright red ring, which is the deposit from Pele¹s plume. The image on the right was acquired in July 1999 and is our best view of the region since 1997. It shows changes that have taken place on the surface since the eruption almost two years ago. The red material from Pele, which probably contains some form of sulfur, has started to cover, but has not yet entirely obscured, the dark material around Pillan. This may indicate that the plumes of both Pillan and Pele are still active. This image also shows that a small, unnamed volcano to the right of Pillan has erupted, depositing dark material surrounded by a yellow ring, which is most visible where it covers some of the dark material from Pillan's 1997 eruption. Some of the color differences between the three images are the effects of different lighting conditions when the images were taken. The apparent change in brightness of the dark feature in the lower left corner (Babbar Patera) and of parts of Pele's red plume deposit, are thought to be due to changes in illumination. However, such illumination changes cannot explain the dramatic changes seen at Pillan. Filters in red, green, and violet wavelengths were combined to produce these images. The color range is slightly enhanced from what the human eye might see at Io. North is to the top of the picture, and the Sun illuminates the surface from the right on the first image, and from the left for the other two. The images are centered at 19 degrees south latitude and 250 degrees west longitude and cover an area approximately 1,650 kilometers wide and 1,750 kilometers high (1,025 miles and 1,090 miles). The resolution of the images on the left and right is about 12 kilometers (7 miles) per picture element. The middle image has a slightly better resolution of about 5 kilometers (3 miles) per picture element. The images taken on April 4, 1997 were from a range of 600,486 kilometers (375,304 miles) by Galileo¹s camera. The images taken on September 19, 1997, were from a range of 505,628 kilometers (316,017 miles). The July 2, 1999 images were taken from a distance of 585,452 kilometers (365,908 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] . |
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Changes at Pillan Patera
PIA02501
Jupiter
Solid-State Imaging
| Title |
Changes at Pillan Patera |
| Original Caption Released with Image |
Dramatic changes have occurred at the volcanically active Pillan Patera region of Jupiter's moon Io over the past three years, as seen in this set of three images taken by NASA¹s Galileo spacecraft. The image on the left was taken in April 1997. The middle image shows the same area in September 1997 [ http://photojournal.jpl.nasa.gov/catalog/PIA01667 ], after a huge eruption occurred. The eruption produced the large, dark deposit just above and to the right of the center. The deposit, which is 400 kilometers (250 miles) in diameter, surrounds Pillan Patera and covers part of the bright red ring, which is the deposit from Pele¹s plume. The image on the right was acquired in July 1999 and is our best view of the region since 1997. It shows changes that have taken place on the surface since the eruption almost two years ago. The red material from Pele, which probably contains some form of sulfur, has started to cover, but has not yet entirely obscured, the dark material around Pillan. This may indicate that the plumes of both Pillan and Pele are still active. This image also shows that a small, unnamed volcano to the right of Pillan has erupted, depositing dark material surrounded by a yellow ring, which is most visible where it covers some of the dark material from Pillan's 1997 eruption. Some of the color differences between the three images are the effects of different lighting conditions when the images were taken. The apparent change in brightness of the dark feature in the lower left corner (Babbar Patera) and of parts of Pele's red plume deposit, are thought to be due to changes in illumination. However, such illumination changes cannot explain the dramatic changes seen at Pillan. Filters in red, green, and violet wavelengths were combined to produce these images. The color range is slightly enhanced from what the human eye might see at Io. North is to the top of the picture, and the Sun illuminates the surface from the right on the first image, and from the left for the other two. The images are centered at 19 degrees south latitude and 250 degrees west longitude and cover an area approximately 1,650 kilometers wide and 1,750 kilometers high (1,025 miles and 1,090 miles). The resolution of the images on the left and right is about 12 kilometers (7 miles) per picture element. The middle image has a slightly better resolution of about 5 kilometers (3 miles) per picture element. The images taken on April 4, 1997 were from a range of 600,486 kilometers (375,304 miles) by Galileo¹s camera. The images taken on September 19, 1997, were from a range of 505,628 kilometers (316,017 miles). The July 2, 1999 images were taken from a distance of 585,452 kilometers (365,908 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] . |
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Migrating Volcanic Plumes on
…
PIA02503
Jupiter
Solid-State Imaging
| Title |
Migrating Volcanic Plumes on Io |
| Original Caption Released with Image |
. 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 ]., This set of four images, taken by NASA's Galileo spacecraft, shows a sequence of volcanic activity on Jupiter's moon Io over the last two years. As seen from left to right, the feature called Masubi [ http://photojournal.jpl.nasa.gov/catalog/PIA02502 ], was observed during Galileo¹s 9th, 10th, 15th, and 22nd orbits of Jupiter. These images show that a plume deposit from Masubi appears in September 1997 and has disappeared eight months later, only to reappear in a different place little more than a year later. The deposit, which originated from a volcanic vent, contains snow rich in sulfur dioxide. Plume deposits are formed when material is blown out of a vent in a continuous, geyser-like, high-velocity eruption, with the material then falling back to Io's surface under the influence of gravity. When it hits the surface, it forms a symmetric ring surrounding the plume vent. The plume deposits are transient features, present only while the associated plume is active and for a brief time afterwards. This sequence of images suggests that the plume deposit visible during Galileo¹s 10th orbit was almost completely gone by the time of its 15th orbit, eight months later. This illustrates how ephemeral the deposits are. Scientists are intrigued by the speed at which the active plume location seems to have migrated. The distance between the centers of the deposits visible in the images from the 10th orbit, second from left, and 22nd orbit, the image on the right, (occurring over a period of less than two years), is about 125 kilometers (78 miles). The plume deposit has changed in size as well as location. The four arrows are the same size and orientation in the images from the 10th and 22nd orbit, showing that the dark ring of material is larger during the 22nd orbit than it was in the 10th orbit. These images were taken through the violet filter of Galileo¹s camera. North is to the top and the Sun illuminates the surface from the left in the images from June 1997 and August 1999, and from the right in the images from September 1997 and May 1998. The images are centered at 50 degrees south latitude and 54 degrees west longitude and cover an area approximately 750 kilometers (470 miles) wide and 1,050 kilometers (660 miles) high. From left to right, the image resolutions are: 16 kilometers (10 miles), 10 kilometers (6.2 miles), 14 kilometers (8 miles), and, 16 kilometers (10 miles) per picture element. From left to right, the images were taken by Galileo¹s camera on the following dates from the following distances from Io: June 17, 1997, at 816,500 kilometers (507,300 miles), September 18, 1997, at 1,046,500 kilometers (650,300 miles), May 30, 1998, at 1,398,500 kilometers (869,000 miles), and August 13, 1999, at 1,565,000 kilometers (972,400). The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ] |
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Masubi Plume on Io
PIA02502
Jupiter
Solid-State Imaging
| Title |
Masubi Plume on Io |
| Original Caption Released with Image |
A plume of gas and particles is ejected some 100 kilometers (about 60 miles) above the surface of Jupiter's volcanic moon Io in this color image, recently taken by NASA¹s Galileo spacecraft. The plume is erupting from near the location of a plume first observed by the Voyager spacecraft in 1979 and named Masubi. However, during the course of the Galileo tour of Jupiter and its moons, a plume has appeared at different locations [ http://photojournal.jpl.nasa.gov/catalog/PIA02503 ] within the Masubi region. This color image is the same as the previously released false color mosaic of Io [ http://photojournal.jpl.nasa.gov/catalog/PIA02309 ], but with special processing to enhance the visibility of the plume. The plume appears blue because of the way small particles in the plume scatter light. North is to the top of the picture, and the Sun illuminates the surface from almost directly behind the spacecraft. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on July 3, 1999 at a distance of about 130,000 kilometers (81,000 miles) by the Galileo¹s camera. (P50590, MRPS95297) The two images on the left are actually the same image displayed indifferent ways. In the top-left image, the Masubi plume is too dim to be seen. The bottom-left image has been processed to enhance the visibility of the plume, which can be seen rising above the bottom-left edge of Io's disk. This processing overexposes the surface of Io so it appears completely white. In the pair of images on the right, a second image has been processed in similar fashion, so that Io's surface features are visible in the top-right image and are overexposed in the bottom-right image. This time Masubi is on the night side of Io, just beyond the terminator (the imaginary line separating day from night), but the plume is high enough that it extends up into the sunlight. A plume from the volcanoPrometheus [ http://photojournal.jpl.nasa.gov/catalog/PIA02505 ], can also be seen in this image, rising above the left edge of Io's disk. The diagonal line in the bottom-right image and the small bright spots sprinkled across all the images are caused by charged particles hitting the camera's CCD (charge-coupled device) detector. North is to the top in all the images. The images on the left were taken by the on August 14, 1999 at a range of 1.1 million kilometers (700,000 miles) and have a resolution of 11 kilometers (7 miles) per picture element. The sun illuminates the surface from behind the spacecraft. The images on the right were taken on August 14, 1999 at a range of 1.6 million kilometers (1 million miles) and have a resolution of 16 kilometers (10 miles) per picture element. The sun illuminates the surface from the left. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
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Masubi Plume on Io
PIA02502
Jupiter
Solid-State Imaging
| Title |
Masubi Plume on Io |
| Original Caption Released with Image |
A plume of gas and particles is ejected some 100 kilometers (about 60 miles) above the surface of Jupiter's volcanic moon Io in this color image, recently taken by NASA¹s Galileo spacecraft. The plume is erupting from near the location of a plume first observed by the Voyager spacecraft in 1979 and named Masubi. However, during the course of the Galileo tour of Jupiter and its moons, a plume has appeared at different locations [ http://photojournal.jpl.nasa.gov/catalog/PIA02503 ] within the Masubi region. This color image is the same as the previously released false color mosaic of Io [ http://photojournal.jpl.nasa.gov/catalog/PIA02309 ], but with special processing to enhance the visibility of the plume. The plume appears blue because of the way small particles in the plume scatter light. North is to the top of the picture, and the Sun illuminates the surface from almost directly behind the spacecraft. The resolution is 1.3 kilometers (0.8 miles) per picture element. The images were taken on July 3, 1999 at a distance of about 130,000 kilometers (81,000 miles) by the Galileo¹s camera. (P50590, MRPS95297) The two images on the left are actually the same image displayed indifferent ways. In the top-left image, the Masubi plume is too dim to be seen. The bottom-left image has been processed to enhance the visibility of the plume, which can be seen rising above the bottom-left edge of Io's disk. This processing overexposes the surface of Io so it appears completely white. In the pair of images on the right, a second image has been processed in similar fashion, so that Io's surface features are visible in the top-right image and are overexposed in the bottom-right image. This time Masubi is on the night side of Io, just beyond the terminator (the imaginary line separating day from night), but the plume is high enough that it extends up into the sunlight. A plume from the volcanoPrometheus [ http://photojournal.jpl.nasa.gov/catalog/PIA02505 ], can also be seen in this image, rising above the left edge of Io's disk. The diagonal line in the bottom-right image and the small bright spots sprinkled across all the images are caused by charged particles hitting the camera's CCD (charge-coupled device) detector. North is to the top in all the images. The images on the left were taken by the on August 14, 1999 at a range of 1.1 million kilometers (700,000 miles) and have a resolution of 11 kilometers (7 miles) per picture element. The sun illuminates the surface from behind the spacecraft. The images on the right were taken on August 14, 1999 at a range of 1.6 million kilometers (1 million miles) and have a resolution of 16 kilometers (10 miles) per picture element. The sun illuminates the surface from the left. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
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Earth-Based Observations of
…
PIA02522
Jupiter
| Title |
Earth-Based Observations of a Fire Fountain on Io |
| Original Caption Released with Image |
This false-color infrared image of the Sunlit disk of Jupiter's moon Io was taken at the NASA Infrared Telescope Facility at Mauna Kea, Hawaii, a few hours after a November 25, 1999 close Io flyby by NASA's Galileo spacecraft. The bright spot at the 1 o'clock position is the same lava fountain seen close-up by Galileo's camera, but in this case it is seen from Earth at a distance of 630 million kilometers (390 million miles). When this image was taken, the fiery lava fountain was almost on the edge of Io's disk and about to disappear from view due to Io's rotation. The lava fountain was seen from an angle just 5.5 degrees above horizontal. Its prominence when seen so obliquely confirms that this eruption is indeed composed of fiery fountains rising up above the surface, horizontal lava flows would be much harder to see from so close to the horizontal. Astronomers making Earth-based telescopic observations see a bright spot like this one somewhere on Io only about 20 percent of the time, so the Galileo team was fortunate to catch one in its narrow field of view. Astronomer John Spencer, who has watched this type of eruption for many years on Io from Mauna Kea, said, "We thought that some of these eruptions might be due to lava fountains, but it's incredible to see that idea confirmed so spectacularly by Galileo." The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted 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 ]. |
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Close-up of Prometheus, Io (
…
PIA02505
Jupiter
Solid-State Imaging
| Title |
Close-up of Prometheus, Io (color) |
| Original Caption Released with Image |
-1999) and NASA's Voyager spacecraft (1979). No other volcano on Io has been so stable in its behavior. However, between the Voyager flybys and the time of Galileo's arrival at Jupiter, the source of the plume has shifted about 70 kilometers (44 miles) to the west. This false color close-up was taken of Prometheus using the near-infrared, green and violet filters (slightly greater than the visible range) of the spacecraft's camera and processed to enhance subtle color variations. The long-lived plume has produced a ring-like deposit of bright white and yellow material that is likely to be rich in sulfur dioxide frost. Also note the denser jets in the plume that point like spokes to its source. Galileo scientists do not yet know whether this long-lived plume is erupting from a vent at the west end of the lava flow, or if the plume is being produced by the advancing lava as it flows over ground rich in sulfur dioxide. Galileo will acquire black and white images of the Prometheus at resolutions between 35 to 70 meters (120 to 230 feet) per picture element and color images at resolutions of about 230 meters (750 feet) per picture element during its close flyby of Jupiter's moon Io on the evening of October 10, 1999 (Pacific time). These images will be important in understanding how volcanic plumes form on Io. In particular, we are interested in seeing if the plume material is escaping from Io's interior or from the surface at the front of active lava flows. These new images may help explain why Prometheus has been so faithfully active. North is to the top of the picture, and the Sun illuminates the surface from almost directly behind the spacecraft. This illumination is good for imaging color variations, but poor for imaging topographic shading. However, some topography is visible here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and rugged areas over parts of Io. The image is centered at 2 degrees south latitude and 154 degrees west longitude. The images were taken at a distance of about 130,000 kilometers (81,000 miles) by Galileo's camera and have a resolution of 1.3 kilometers or 0.8 miles per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., The volcano called Prometheus, found on Jupiter's moon Io, could be called the Old Faithful of the outer solar system, because its volcanic plume has been visible every time it has been observed since 1979. This particular image, one of the highest-resolution pictures ever taken of Io, was obtained by NASA's Galileo spacecraft as it approached Io on July 3, 1999. The volcanic plume of Prometheus has been visible during observations by Galileo (1996 [ http://photojournal.jpl.nasa.gov/catalog/PIA00495 ] |
|
Close-up of Prometheus, Io (
…
PIA02505
Jupiter
Solid-State Imaging
| Title |
Close-up of Prometheus, Io (color) |
| Original Caption Released with Image |
-1999) and NASA's Voyager spacecraft (1979). No other volcano on Io has been so stable in its behavior. However, between the Voyager flybys and the time of Galileo's arrival at Jupiter, the source of the plume has shifted about 70 kilometers (44 miles) to the west. This false color close-up was taken of Prometheus using the near-infrared, green and violet filters (slightly greater than the visible range) of the spacecraft's camera and processed to enhance subtle color variations. The long-lived plume has produced a ring-like deposit of bright white and yellow material that is likely to be rich in sulfur dioxide frost. Also note the denser jets in the plume that point like spokes to its source. Galileo scientists do not yet know whether this long-lived plume is erupting from a vent at the west end of the lava flow, or if the plume is being produced by the advancing lava as it flows over ground rich in sulfur dioxide. Galileo will acquire black and white images of the Prometheus at resolutions between 35 to 70 meters (120 to 230 feet) per picture element and color images at resolutions of about 230 meters (750 feet) per picture element during its close flyby of Jupiter's moon Io on the evening of October 10, 1999 (Pacific time). These images will be important in understanding how volcanic plumes form on Io. In particular, we are interested in seeing if the plume material is escaping from Io's interior or from the surface at the front of active lava flows. These new images may help explain why Prometheus has been so faithfully active. North is to the top of the picture, and the Sun illuminates the surface from almost directly behind the spacecraft. This illumination is good for imaging color variations, but poor for imaging topographic shading. However, some topography is visible here due to the combination of relatively high resolution (1.3 kilometers or 0.8 miles per picture element) and rugged areas over parts of Io. The image is centered at 2 degrees south latitude and 154 degrees west longitude. The images were taken at a distance of about 130,000 kilometers (81,000 miles) by Galileo's camera and have a resolution of 1.3 kilometers or 0.8 miles per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]., The volcano called Prometheus, found on Jupiter's moon Io, could be called the Old Faithful of the outer solar system, because its volcanic plume has been visible every time it has been observed since 1979. This particular image, one of the highest-resolution pictures ever taken of Io, was obtained by NASA's Galileo spacecraft as it approached Io on July 3, 1999. The volcanic plume of Prometheus has been visible during observations by Galileo (1996 [ http://photojournal.jpl.nasa.gov/catalog/PIA00495 ] |
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Europa: Sea Salts or Battery
…
PIA02529
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Europa: Sea Salts or Battery Acid |
| Original Caption Released with Image |
This composite image of the Jupiter-facing hemisphere of Europa was obtained on November 25, 1999 by two instruments onboard NASA's Galileo spacecraft. The global black-and-white view, by the spacecraft's camera, provides the highest resolution view ever obtained of this side of Europa. The superimposed false-color image, obtained by Galileo's near-infrared mapping spectrometer instrument, reveals the presence of materials with differing compositions on Europa's surface. In this image, blue areas represent the cleanest, brightest icy surfaces, while the reddest areas have the highest concentrations of darker, non-ice materials. The mixture of colors seen here is most likely the result of both variations in the ages and composition of surface materials. The dark materials are believed to fade with the passage of time. This area is highly unusual compared to many other areas on Europa because of its high concentration of fresh-appearing bright ridges and fractures. On other parts of Europa, the darker areas appear to be the most recently formed, but here the ridges and fractures appear to "overprint" the underlying darker mottled terrain. Scientists disagree about the chemical makeup of the dark materials, both sulfuric acid (common battery acid) and salty minerals, perhaps from a subsurface ocean, have been suggested. Analysis of images like this one may help to resolve this controversy. Surprisingly, either material could help to produce conditions below the surface that could be favorable to the formation of living organisms. The colored area is centered near the intersection of the equator and the European "prime meridian," where the longitude is assigned the value of 0 degrees. This is the sub-Jupiter point, where Jupiter always appears to be almost directly overhead. This phenomenon occurs because Europa takes the same period of time to rotate as it does to orbit around Jupiter (3.55 days). The area imaged in color is about 400 by 400 kilometers (250 by 250 miles), an area of about 160,000 square kilometers (about 62,000 square miles). Click on this thumbnail image above to view the above image in a Global context. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo 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 ]. |
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Europa: Sea Salts or Battery
…
PIA02529
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Europa: Sea Salts or Battery Acid |
| Original Caption Released with Image |
This composite image of the Jupiter-facing hemisphere of Europa was obtained on November 25, 1999 by two instruments onboard NASA's Galileo spacecraft. The global black-and-white view, by the spacecraft's camera, provides the highest resolution view ever obtained of this side of Europa. The superimposed false-color image, obtained by Galileo's near-infrared mapping spectrometer instrument, reveals the presence of materials with differing compositions on Europa's surface. In this image, blue areas represent the cleanest, brightest icy surfaces, while the reddest areas have the highest concentrations of darker, non-ice materials. The mixture of colors seen here is most likely the result of both variations in the ages and composition of surface materials. The dark materials are believed to fade with the passage of time. This area is highly unusual compared to many other areas on Europa because of its high concentration of fresh-appearing bright ridges and fractures. On other parts of Europa, the darker areas appear to be the most recently formed, but here the ridges and fractures appear to "overprint" the underlying darker mottled terrain. Scientists disagree about the chemical makeup of the dark materials, both sulfuric acid (common battery acid) and salty minerals, perhaps from a subsurface ocean, have been suggested. Analysis of images like this one may help to resolve this controversy. Surprisingly, either material could help to produce conditions below the surface that could be favorable to the formation of living organisms. The colored area is centered near the intersection of the equator and the European "prime meridian," where the longitude is assigned the value of 0 degrees. This is the sub-Jupiter point, where Jupiter always appears to be almost directly overhead. This phenomenon occurs because Europa takes the same period of time to rotate as it does to orbit around Jupiter (3.55 days). The area imaged in color is about 400 by 400 kilometers (250 by 250 miles), an area of about 160,000 square kilometers (about 62,000 square miles). Click on this thumbnail image above to view the above image in a Global context. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo 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 ]. |
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Ionian Mountains and Caldera
…
PIA02526
Jupiter
Solid-State Imaging
| Title |
Ionian Mountains and Calderas, in Color |
| Original Caption Released with Image |
This picture of Jupiter's volcanic moon Io combines high-resolution black and white images taken by NASA's Galileo spacecraft on October 10, 1999, with lower resolution color images taken by Galileo on July 3, 1999 to help scientists better understand the relationships between the different surface materials and the underlying geologic structures. For example, there is red material, which is often associated with areas where lava is erupting onto the surface and is thought to be a compound of sulfur, around the margin of Monan Patera (the elongated caldera just to the lower right of center). The broad circle of bright, white material (just to the left of center) is thought to be sulfur-dioxide which is being deposited from the plume Amirani. The lengths of the shadows cast by the mountains make it possible to estimate the mountains¹ heights. The southern mountain on the far right of the mosaic is approximately 8 kilometers (26,000 feet) high and the mountain to the north of it is approximately 4 kilometers (13,000 feet) high. North is to the top and the image is centered at 22.8 degrees north latitude and 109.5 degrees west longitude. The higher resolution images have a sharpness of about 500 meters (or yards) per picture element and they are illuminated from the left. These images were taken at a range of 25,000 kilometers (15,500 miles). The color images are illuminated from almost directly behind the spacecraft. The color images were taken at a distance of about 130,000 kilometers (81,000 miles) and show a resolution of 1.3 kilometers (0.8 miles) per picture element. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the Galileo 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 ]. |
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Bright Channelized Lava Flow
…
PIA02518
Jupiter
Solid-State Imaging
| Title |
Bright Channelized Lava Flows on Io |
| Original Caption Released with Image |
This image of Jupiter's moon Io, taken by NASA's Galileo spacecraft on November 25, 1999, shows a bright lava flow with a distinct dark channel in the middle. This type of winding channel is a common sight on shallow slopes in lava flows on Earth that are moving fairly quickly. The serrated margins are characteristic of fluid lava that is able to work its way into every available nook and crevice. What is unusual about this lava flow is its bright color -- most lava flows on Io and the other planets are dark. This leads Galileo scientists to speculate that these lava flows are composed of sulfur, rather than silicate rock. The lava flow appears to emanate from a caldera named Emakong, which is just beyond the left edge of the picture. North is to the upper left of the picture and the Sun illuminates the surface from almost behind the spacecraft. The image, centered at -3.7degrees latitude and 117.4 degrees longitude, covers an area approximately 120 by 40 kilometers (75 by 25 miles). The resolution is 150 meters (500 feet) per picture element. The image was taken at a range of 15,000 kilometers (9,400 miles) by the camera onboard Galileo. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology in Pasadena. This image and other images and data received from Galileo are posted 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 ]. |
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Lava Fountains on Io
PIA02519
Jupiter
Solid-State Imaging
| Title |
Lava Fountains on Io |
| Original Caption Released with Image |
This mosaic of images collected by NASA's Galileo spacecraft on Thanksgiving Day, November 25,1999 shows a fountain of lava spewing above the surface of Jupiter's moon Io. The active lava was hot enough to cause what the camera team describes as "bleeding" in Galileo's camera, caused when the camera's detector is so overloaded by the brightness of the target that electrons spill down across the detector. This shows up as a white blur in the image. Most of the hot material is distributed along a wavy line which is interpreted to be hot lava shooting more than 1.5 kilometers (1-mile) high out of a long crack, or fissure, on the surface. There also appear to be additional hot areas below this line, suggesting that hot lava is flowing away from the fissure [ http://photojournal.jpl.nasa.gov/catalog/PIA02525 ]. Initial estimates of the lava temperature [ http://photojournal.jpl.nasa.gov/catalog/PIA02521 ], indicate that it is well above 1,000 Kelvin (1,300 Fahrenheit) and might even be hotter than 1,600 Kelvin (2,400 Fahrenheit). These images were targeted to provide the first close-up view of a chain of huge calderas (large volcanic collapse pits). These calderas are some of the largest on Io and they dwarf other calderas across the solar system. At 290 by 100 kilometers (180 by 60 miles), this chain of calderas covers an area seven times larger than the largest caldera on the Earth. The new images show the complex nature of this giant caldera on Io, with smaller collapses occurring within the elongated caldera. Also of great interest is the flat-topped mesa on the right. The scalloped margins are typical of a process geologists call "sapping," which occurs when erosion is caused by a fluid escaping from the base of a cliff. On Earth, such sapping features are caused by springs of groundwater. Similar features on Mars are one of the key pieces of evidence for past water on the Martian surface. However, on Io, the liquid is presumed to be pressurized sulfur dioxide. The liquid sulfur dioxide should change to a gas almost instantaneously upon reaching the near-vacuum of Io's surface, blasting away material at the base of the cliff. The sulfur dioxide gas eventually freezes out on the surface of Io in the form of a frost. As the frost is buried by later deposits, it can be heated and pressurized until it becomes a liquid. This liquid then flows out of the ground, completing Io's version of the "water cycle." North is to the upper left of the picture and the Sun illuminates the surface from the lower left. The image, centered at 61.1 degrees latitude and 119.4 degrees longitude, covers an area approximately 300 by 75 kilometers (190-by-47 miles). The resolution is 185 meters (610 feet) per picture element. The image was taken at a range of 17,000 kilometers(11,000 miles) by Galileo's onboard camera. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted 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 ]. |
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Pele's Hot Caldera Margin
PIA02511
Jupiter
Solid-State Imaging
| Title |
Pele's Hot Caldera Margin |
| Original Caption Released with Image |
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 ]., The volcano Pele glows in the night in this close-up image of Jupiter's moon Io, obtained by NASA's Galileo spacecraft in the closest-ever Io flyby on October 10, 1999. Only surfaces hotter than 600 degrees Celsius (1,100 degrees Fahrenheit) are visible in this image. The hot material forms a thin, curving line more than 10 kilometers (6 miles) long and up to 50 meters (150 feet) wide. Galileo scientists believe that the changes in brightness along the curving line are due to variations in the amount of hot lava exposed at the surface. Data acquired previously suggest that the liquid lava at Pele is over 1,200 degrees Celsius (2,200 degrees Fahrenheit). Such lava would cool and become invisible in this image in just a few minutes. Therefore, this image outlines parts of the volcano that are at most a few minutes old. The outline of the fresh, hot material is superimposed on the best daytime image of Pele (bottom), showing that the hot material follows the margin of Pele's caldera. A caldera is a depression caused by collapse during a volcanic eruption. Galileo scientists hypothesize that the Pele caldera is filled with liquid lava, with the floating crust broken-up along the margins where it hits the cliffs along the caldera's walls. The lava lake is probably confined to the dark, southern part of the Pele caldera, which covers an area of about 15 by 10 kilometers (10 by 6 miles). Previous data collected by Galileo indicate that hot material covers only an area of about 800 by 800 meters (0.5 by 0.5 miles). This suggests that most of the lava lake is covered by a cooler crust that floats on top of the molten lava. The behavior of this lava lake is similar to that of Hawaiian lava lakes, although Pele covers an area several thousand times larger than the lakes in Hawaii. Interestingly, the image of Pele's caldera obtained by Galileo in October shows only about one-percent of thehot area was known to be on the volcano [ http://photojournal.jpl.nasa.gov/catalog/PIA02510 ]. This indicates that 99-percent of the activity at Pele is in a region that was not imaged in this flyby. Pu'u O'o lava lake, Hawaii, 1992 North is to the top of the picture and the sun is on the other side of Io. It is centered at 18.6 degrees south latitude and 255.7 degrees west longitude, looking obliquely at an area approximately 10 kilometers (6 miles) by 10 kilometers (6 miles) in size. The picture has a resolution of 30 meters (100 feet) per picture element and is taken in the clear filter using a 45.8 millisecond exposure time. The images were taken by the camera onboard Galileo from a range of about 1,400 kilometers (840 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at |
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Pele's Hot Caldera Margin
PIA02511
Jupiter
Solid-State Imaging
| Title |
Pele's Hot Caldera Margin |
| Original Caption Released with Image |
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 ]., The volcano Pele glows in the night in this close-up image of Jupiter's moon Io, obtained by NASA's Galileo spacecraft in the closest-ever Io flyby on October 10, 1999. Only surfaces hotter than 600 degrees Celsius (1,100 degrees Fahrenheit) are visible in this image. The hot material forms a thin, curving line more than 10 kilometers (6 miles) long and up to 50 meters (150 feet) wide. Galileo scientists believe that the changes in brightness along the curving line are due to variations in the amount of hot lava exposed at the surface. Data acquired previously suggest that the liquid lava at Pele is over 1,200 degrees Celsius (2,200 degrees Fahrenheit). Such lava would cool and become invisible in this image in just a few minutes. Therefore, this image outlines parts of the volcano that are at most a few minutes old. The outline of the fresh, hot material is superimposed on the best daytime image of Pele (bottom), showing that the hot material follows the margin of Pele's caldera. A caldera is a depression caused by collapse during a volcanic eruption. Galileo scientists hypothesize that the Pele caldera is filled with liquid lava, with the floating crust broken-up along the margins where it hits the cliffs along the caldera's walls. The lava lake is probably confined to the dark, southern part of the Pele caldera, which covers an area of about 15 by 10 kilometers (10 by 6 miles). Previous data collected by Galileo indicate that hot material covers only an area of about 800 by 800 meters (0.5 by 0.5 miles). This suggests that most of the lava lake is covered by a cooler crust that floats on top of the molten lava. The behavior of this lava lake is similar to that of Hawaiian lava lakes, although Pele covers an area several thousand times larger than the lakes in Hawaii. Interestingly, the image of Pele's caldera obtained by Galileo in October shows only about one-percent of thehot area was known to be on the volcano [ http://photojournal.jpl.nasa.gov/catalog/PIA02510 ]. This indicates that 99-percent of the activity at Pele is in a region that was not imaged in this flyby. Pu'u O'o lava lake, Hawaii, 1992 North is to the top of the picture and the sun is on the other side of Io. It is centered at 18.6 degrees south latitude and 255.7 degrees west longitude, looking obliquely at an area approximately 10 kilometers (6 miles) by 10 kilometers (6 miles) in size. The picture has a resolution of 30 meters (100 feet) per picture element and is taken in the clear filter using a 45.8 millisecond exposure time. The images were taken by the camera onboard Galileo from a range of about 1,400 kilometers (840 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at |
|
Ongoing Geologic Activity at
…
PIA02512
Jupiter
Solid-State Imaging
| Title |
Ongoing Geologic Activity at Prometheus Volcano, Io |
| Original Caption Released with Image |
Map of Prometheus North is to the top in all images and the sun is illuminating the surface from slightly to the left of overhead. All the images are centered at 2 degrees south and 154 degrees west. The top image has a resolution of 1.5 kilometers (about one mile) per picture element and the high-resolution inset has a resolution of 120 meters (390 feet). The color image at the bottom has a resolution of 2.6 kilometers (1.6 miles) per picture element. The two black and white image at the bottom have resolutions of 1.5 kilometers (about one mile) per picture element. This image and other images and data received from Galileo are posted 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 ]., This collage of images shows the dizzying rate of geologic activity at one of the many erupting volcanoes on Jupiter's moon Io, as viewed by NASA's Galileo spacecraft during the closest-ever Io flyby on October 10, 1999. The top panel shows the best overall view of the Prometheus volcano, combining a picture at a resolution of 120 meters (400 feet) per picture element with a picture at a resolution of 1.5 kilometers (about one mile) per picture element. Inset within this panel is a smaller copy of the mosaic with a temperature map superimposed. The Galileo camera took the pictures, while the temperatures were measured by the spacecraft's near infrared mapping spectrometer instrument. Combining these data, Galileo scientists have created a description of the eruption at Prometheus. The magma is stored in an underground chamber beneath the caldera (dark, bean-shaped feature) at the northeastern end of Prometheus (top right). The lava reaches the surface about 15 kilometers(10 miles) south of the caldera. This point is marked by the blue, eastern hot spot in the temperature map and by a streak of red, sulfur-rich material (see color panel on the lower left). From the volcanic vent, the lava travels almost 100 kilometers (60 miles) through lava tubes to the front of the flow. The exposed liquid lava produces the large high temperature area on the western end of Prometheus (color panel at lower left). A 100 kilometer(60 mile) tall plume of sulfur-dioxide rich gas also rises above these active lava flows. A smaller breakout of liquid lava midway along the tube forms a faint (purple) hot spot. Scientists at the University of Arizona, compared the pictures taken on July 3rd [ http://photojournal.jpl.nasa.gov/catalog/PIA02505 ] and October 10th of this year. They found that changes (see middle and right lower panels) have occurred in the intervening 3 months. A breakout from the middle of the lava tube appears to have taken place within this three-month period, spreading a new dark deposit to the north of the older lava flows. It also appears that the gas discharge from the volcanic vent at the eastern end of the flow has increased. There is a new fan of dark material streaming out from this location. Furthermore, the new, bright crescent-shaped deposit across the middle of Prometheus suggests that the main (western) plume has been pushed aside by the increased gas release to the east. |
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Ongoing Geologic Activity at
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PIA02512
Jupiter
Solid-State Imaging
| Title |
Ongoing Geologic Activity at Prometheus Volcano, Io |
| Original Caption Released with Image |
Map of Prometheus North is to the top in all images and the sun is illuminating the surface from slightly to the left of overhead. All the images are centered at 2 degrees south and 154 degrees west. The top image has a resolution of 1.5 kilometers (about one mile) per picture element and the high-resolution inset has a resolution of 120 meters (390 feet). The color image at the bottom has a resolution of 2.6 kilometers (1.6 miles) per picture element. The two black and white image at the bottom have resolutions of 1.5 kilometers (about one mile) per picture element. This image and other images and data received from Galileo are posted 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 ]., This collage of images shows the dizzying rate of geologic activity at one of the many erupting volcanoes on Jupiter's moon Io, as viewed by NASA's Galileo spacecraft during the closest-ever Io flyby on October 10, 1999. The top panel shows the best overall view of the Prometheus volcano, combining a picture at a resolution of 120 meters (400 feet) per picture element with a picture at a resolution of 1.5 kilometers (about one mile) per picture element. Inset within this panel is a smaller copy of the mosaic with a temperature map superimposed. The Galileo camera took the pictures, while the temperatures were measured by the spacecraft's near infrared mapping spectrometer instrument. Combining these data, Galileo scientists have created a description of the eruption at Prometheus. The magma is stored in an underground chamber beneath the caldera (dark, bean-shaped feature) at the northeastern end of Prometheus (top right). The lava reaches the surface about 15 kilometers(10 miles) south of the caldera. This point is marked by the blue, eastern hot spot in the temperature map and by a streak of red, sulfur-rich material (see color panel on the lower left). From the volcanic vent, the lava travels almost 100 kilometers (60 miles) through lava tubes to the front of the flow. The exposed liquid lava produces the large high temperature area on the western end of Prometheus (color panel at lower left). A 100 kilometer(60 mile) tall plume of sulfur-dioxide rich gas also rises above these active lava flows. A smaller breakout of liquid lava midway along the tube forms a faint (purple) hot spot. Scientists at the University of Arizona, compared the pictures taken on July 3rd [ http://photojournal.jpl.nasa.gov/catalog/PIA02505 ] and October 10th of this year. They found that changes (see middle and right lower panels) have occurred in the intervening 3 months. A breakout from the middle of the lava tube appears to have taken place within this three-month period, spreading a new dark deposit to the north of the older lava flows. It also appears that the gas discharge from the volcanic vent at the eastern end of the flow has increased. There is a new fan of dark material streaming out from this location. Furthermore, the new, bright crescent-shaped deposit across the middle of Prometheus suggests that the main (western) plume has been pushed aside by the increased gas release to the east. |
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Europa's Jupiter-Facing Hemi
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PIA02528
Jupiter
Solid-State Imaging
| Title |
Europa's Jupiter-Facing Hemisphere |
| Original Caption Released with Image |
This 12-frame mosaic provides the highest resolution view ever obtained of the side of Jupiter's moon Europa that faces the giant planet. It was obtained by the camera onboard NASA's Galileo spacecraft on November 25, 1999 during the spacecrafts 25th orbit of Jupiter. The new images have resolutions of about 1 kilometer (0.6 miles) per picture element. Lower resolution context was provided by images acquired during earlier Galileo orbits. In the earlier images, the resolution is 7 and 13 kilometers (4 and 8 miles) per picture element, respectively. Numerous linear features in the center of the mosaic and toward the poles may have formed in response to tides strong enough to fracture Europa's icy surface. Some of these features extend for over 1,500 kilometers (900 miles). Darker regions near the equator on the eastern (right) and western (left) limb may be vast areas of chaotic terrain. Bright white spots near the western limb are the ejecta blankets of young impact craters. North is to the top of the picture and the sun illuminates the surface from the left. The image, centered at 0 latitude and 10 longitude, covers an area approximately 2,500 by 3,000 kilometers. The finest details that can discerned in this picture are about 2 kilometers across (about 1,550 by 1,860 miles). The images were taken by Galileo's camera on November 25, 1999 when the spacecraft was 94,000 kilometers (58,000 miles) from Europa. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted 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 ]. |
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Zal Patera, Io, in color
PIA02527
Jupiter
Solid-State Imaging
| Title |
Zal Patera, Io, in color |
| Original Caption Released with Image |
The Zal Patera region of Jupiter's volcanic moon Io is shown in this combination of high-resolution black and white images taken by NASA's Galileo spacecraft on November 25, 1999 and lower resolution color images taken by Galileo on July 3, 1999. By combining both types of images, Galileo scientists can better understand the relationships between the different surface materials and the underlying geologic structures. For example, in the center toward the top of the picture, the edge of the caldera, or volcanic crater, is marked by the black flows, and it coincides with the edge of a plateau. Also, the red material(just above and to the right of the center of the image) is typically associated with regions where lava is erupting onto the surface. Here the red material follows the base of a mountain, which may indicate that sulfurous gases are escaping along a fault associated with the formation of the mountain. Scientists can use the lengths of the shadows cast to estimate the height of the mountains. They estimate that the northernmost plateau, which bounds the western edge of Zal Patera, rises up to approximately 2 kilometers (6,600 feet) high. The mountain to the south of the caldera has peaks up to approximately 4.6 kilometers (15,000 feet) high, while the small peak at the bottom of the picture is approximately 4.2 kilometers (14,000 feet) high. North is to the top of the image, which is centered at 33.7 degrees north latitude and 81.9 degrees west longitude. The higher resolution images have a sharpness of about 260 meters (or yards) per picture element, and they are illuminated from the left. These images were taken on November 25, 1999 at a range of 26,000 kilometers (16,000 miles). The color images are illuminated from almost directly behind the Galileo spacecraft. The resolution of the color images is 1.3 kilometers (0.8 miles) per picture element. They were taken on July 3, 1999 at a distance of about 130,000 kilometers (81,000 miles). The Jet Propulsion Laboratory, Pasadena, CA manages Galileo for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted 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 ]. |
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Collapsing Mountains on Io
PIA02513
Jupiter
Solid-State Imaging
| Title |
Collapsing Mountains on Io |
| Original Caption Released with Image |
) shows a lumpy landscape. Curiously, the variation in brightness between the dark and light areas within this image is the greatest seen to date on Io. Galileo scientists are continuing to investigate the processes that produce this puzzling surface. The Sun illuminates the surface from the left in all five images. North is to the top in the top four images. In order to keep the Sun angle consistent in all of the images, north is to the bottom in the bottom image. The upper left image is centered at 18.7 degrees north latitude, 81.4 degrees west longitude, and covers a region 175 kilometers (108 miles)by 170 kilometers (106 miles). The lower left image is centered at about one degree north latitude and 81.7 degrees west longitude and covers a region 135 kilometers (84 miles) by 200 kilometers (124 miles). The middle image is centered at 25.6 degrees north latitude, 96.7 degrees west longitude and covers a region 130 kilometers (81 miles) by 275 kilometers(170 miles). The right image is centered at 14.4 degrees north latitude, 104.7 degrees west longitude and covers a region 125 kilometers (78 miles)by 205 kilometers (130 miles). The bottom image is centered at 4 degrees north latitude and 214.6 degrees west longitude and was taken at a range of 882 kilometers (548 miles). The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted on the World Wide Web, 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 ]., Unusual mountains on Jupiter's moon Io are shown in these images that were captured by NASA's Galileo spacecraft during its close Io flyby on October 10, 1999. The top four pictures show four different mountains at resolutions of about 500 meters (1,600 feet) per picture element. The bottom picture is a closeup of another mountain. It is also one of the highest resolution images ever obtained of Io, with a resolution of 9 meters (30 feet) per picture element. The lower resolution images show a range of mountain structures from angular peaks on the left to gentler plateaus, surrounded by very gently sloping debris aprons on the right. Galileo scientists believe that these images illustrate the deterioration of Ionian mountains. If this is the case, it means that the more angular mountains on the left are younger than the rounded mountains on the right. Almost all of the mountains exhibit ridges parallel to their margins. These ridges indicate material is moving down the sides of the mountains due to gravity. The ridges are similar to structures observed at the base of Olympus Mons on Mars, so comparative studies may help us understand surface processes on both planets. The very high-resolution image shows a closeup of a degraded mountain. This image (which is strikingly different from the other image of comparable resolution which targeted recent lava flows [ http://photojournal.jpl.nasa.gov/catalog/PIA02507 ] |
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Galileo discovers caldera at
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PIA02508
Jupiter
Solid-State Imaging
| Title |
Galileo discovers caldera at Prometheus Volcano, Io |
| Original Caption Released with Image |
http://galileo.jpl.nasa.gov/images/images.html [ http://galileo.jpl.nasa.gov/images/images.html ]., This is a high-resolution image of part of Prometheus, an active volcano on Jupiter's volcanic moon Io. The image was taken by NASA's Galileo spacecraft on October 10, 1999, during its close flyby of Io. It shows a volcanic caldera, a large depression formed by the collapse of the ground after a volcanic eruption. Some terrestrial examples of calderas can be found in Hawaii. This image also shows dark lava flows and a strange, lumpy surface covered with sulfur-rich snow. The new image is shown over an earlier, color view. In earlier, lower resolution images [ http://photojournal.jpl.nasa.gov/catalog/PIA02505 ], it appeared that all the dark material at Prometheus comprised a single, long lava flow. The new image shows for the first time that the northeastern end of this dark feature is actually a lava-filled caldera 28 kilometers (17 miles) long and 14 kilometers (9 miles) wide. The underground source of the Prometheus lava is probably beneath this newly discovered caldera. The lava flows that spill over the west rim of the newly discovered caldera clearly indicate that, at some point in time, the entire caldera was filled with lava. It is not clear whether the lava to the south of the caldera originally erupted within the caldera and flowed out, or if it erupted from a vent in the south and then flowed north into the caldera. Galileo scientists are intrigued also by the snowfield containing hummocks, seen to the east of the Prometheus caldera. They are currently examining a number of alternative models for their formation. One idea is that the hummocks, or routed knolls, are the results of the supersonic blasts from Io's volcanoes plastering material onto one side of pre-existing lumps on the ground. The black and white, high-resolution image was taken with a filter that let in only a part of the infrared spectrum close to the visible wavelengths. The "color" of materials in the infrared is an important tool in determining the chemical composition of planetary surfaces [ http://photojournal.jpl.nasa.gov/catalog/PIA02509 ]. North is to the top of the picture and the sun illuminates the surface from almost behind the spacecraft. The resolution is 120 meters (400 feet) per pixel element. This resolution is more than 10 times better than the previous best view of this region. The image covers an area about 96 kilometers (60 miles) wide and 29 kilometers (18 miles) high. It was taken at a distance of 12,000 kilometers (7,500 miles) from Io by the camera onboard Galileo. 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 http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ]. Background information and educational context for the images can be found at |
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Galileo's Near-Infrared Mapp
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PIA02509
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Galileo's Near-Infrared Mapping Spectrometer Detects Active Lava Flows at Prometheus Volcano, Io |
| Original Caption Released with Image |
The active volcano Prometheus on Jupiter's moon Io was imaged by the near-infrared mapping spectrometer instrument onboard NASA's Galileo spacecraft during the close flyby of Io on October 10, 1999. The images were taken at a distance of about 15,000 kilometers (9,400 miles). The spectrometer can detect active volcanoes on Io by measuring their heat in the near-infrared wavelengths (just beyond the red end of human vision). It can also obtain information on the composition of materials on Io¹s surface using the same wavelengths. The image on the left, taken at an infrared wavelength, shows the different compositions of materials on the volcano. The dark material is thought to be silicate lava, and the white material is sulfur dioxide frost. Sulfur dioxide erupts out of this volcano as a plume and condenses into snow by the time it reaches the ground, forming a distinctive white ring around the volcano. The image on the right was taken at a longer infrared wavelength that shows heat coming out of the volcano. The hottest areas appear white and the coolest appear black. From this image, it is clear that there are two major "hot spots" (high-temperature areas) on this volcano. The hottest area (white spot on the left) corresponds to a location where images taken by Galileo's camera show a complex lava flow field. The cooler "hot spot" (green spot on the right) is located near where camera images show a newly-discovered volcanic caldera [ http://photojournal.jpl.nasa.gov/catalog/PIA02508 ]. The high temperatures at both hot spots are probably due to active lava flowing on the surface. Previous observations of the Prometheus region by the spectrometer, taken when the spacecraft was at much greater distances from Io, showed Prometheus to be a persistently active volcano. Temperatures calculated from spectrometer data areas high as about 800 degrees Celsius or 1,500 Fahrenheit), similar to those of cooling lava flows in Hawaii. 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 http://galileo.jpl.nasa.gov/ [ http://galileo.jpl.nasa.gov/ ] Background information and educational context for the images can be found athttp://galileo.jpl.nasa.gov/images/images.html [ http://galileo.jpl.nasa.gov/images/images.html ] |
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Galileo PPR temperature maps
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PIA02524
Jupiter
| Title |
Galileo PPR temperature maps of Loki in October 1999 |
| Original Caption Released with Image |
Like a terrestrial weather map, this map made by the photopolarimeter-radiometer onboard NASA's Galileo spacecraft shows how temperatures vary across the surface of Jupiter's moon Io. However, in this case the temperatures are due to volcanic activity, not weather. The maps show Io's most powerful volcano, Loki, which was in the throes of one of its periodic bright eruptions when the map was made during Galileo's close flyby of Io on October. The background to the temperature map is a Galileo image of Loki taken earlier in the Galileo mission. Loki's most prominent feature is the huge horseshoe-shaped dark caldera, 200 kilometers (120 miles) across. These observations reveal that most of the lava lake is at a remarkably uniform temperature, about -23 degrees C (-9 degrees F). This is chilly by Earth standards, but on Io, where most of the surface is colder than -145 degrees C (-230 degrees F), enormous amounts of volcanic heat are required to keep such a large area at this temperature. The uniform temperature, which was also seen by Galileo's Near Infrared Mapping Spectrometer, could be due to a uniformly thick frozen crust over a lake of molten lava, or to a series of old lava flows that have been cooling down for a year or two since they erupted. The southwestern corner of the caldera is much hotter the highest resolution photopolarimeter-radiometer observation shows peak temperatures of at least 126 degrees C (260 F). It is likely that this is the site of the new eruption that began in September, and that fresh lava erupting there will eventually spill out from this region to warm up the parts of the caldera to the east and north. The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA. This image and other images and data received from Galileo are posted 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 ]. |
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