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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
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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 Prometheus, Io (
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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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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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Ionian Mountains and Caldera
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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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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 |
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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
…
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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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
…
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
…
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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Reconstruction of Scrambled
…
PIA02517
Jupiter
Solid-State Imaging
| Title |
Reconstruction of Scrambled Io Images |
| Original Caption Released with Image |
This pair of images depicts the magic worked by JPL engineers to repair radiation damage to images taken by NASA's Galileo spacecraft camera during an October 10 close flyby of Jupiter's volcanic moon Io. The majority of the Io images acquired by Galileo that day were taken in a camera mode in which 2x2 blocks of picture elements are supposed to be added together during readout of the image from the detector. Because the environment around Io has very high radiation, this mode was implemented to provide additional protection against corruption of the images due to radiation-induced noise. However, apparently due to accumulated radiation damage to the camera electronics, this readout mode did not function properly during the flyby. The effect was that the right and left sides of the images were added together during readout, rather than adjacent pairs of picture elements. This produced something akin to a double-exposed image. Engineers figured out how the images had been garbled by carefully examining the images and the way the detector readout is commanded. Until recently, it was thought that repair of the images would be impossible. However, an innovative technique has just been developed at JPL for separating the two halves without introducing excessive errors. The scrambled raw data were unscrambled by a program developed using the LabVIEW software from National Instruments of Austin, TX. The image recovery results have been amazing. They allow for reliable analysis of the surface morphologies seen in the Io images. The image shown here (left: -- original scrambled image, right -reconstructed image) covers a portion of the lava flows emanating from avolcanic center on Io named Zamama [ http://photojournal.jpl.nasa.gov/catalog/PIA02504 ]. The intricate, convoluted margins of the flows are characteristic of "pahoehoe" (smooth, ropy) lava flows seen on Earth, and provide information on how the lava erupted and advanced over the ground. North is to the lower left of the picture and the Sun illuminates the surface from the lower left. The image, centered at 17.7 degrees latitude and 172.2 degrees longitude, covers an area approximately 16 by 16 kilometers (10 by 10 miles). The finest details that can be discerned in this picture are about 80 meters (260 feet) across. The image was taken on October 10, 1999 at a range of 1,800 kilometers (1,100 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 in Pasadena. This image and other images and data received from Galileo are posted 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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Earth-based images of the Fa
…
PIA02523
Jupiter
| Title |
Earth-based images of the Fall 1999 Loki Eruption |
| Original Caption Released with Image |
These false-color images of Io and Jupiter were taken with the NASA Infrared Telescope Facility at Mauna Kea, Hawaii, as part of a campaign to support closeup Io observations by NASA's Galileo spacecraft. These and other Earth-based observations show that Io's most powerful volcano, Loki, began one of its periodic major eruptions about a month before Galileo's October Io flyby, and that the eruption was continuing during the Galileo flyby. These infrared images (taken at a wavelength of 3.8 microns) show Sunlight reflected from the edge of Jupiter's disk on the left-hand side, and the heat from several glowing volcanoes on Io on the right. Io is in Jupiter's shadow, so no Sunlight falls on it -- the volcanoes are all we see. On August 9, 1999 (left), several volcanoes glowed faintly with roughly equal brightness. However, on October 10, 1999, roughly 20 hours before Galileo flew past, a single volcano, Loki, dominated the image. Loki brightened by a factor of ten in the period between these images. Other observations from the NASA Infrared Telescope and from Wyoming Infrared Telescope near Laramie operated by the University of Wyoming show that most of this brightening occurred during September. Earth-based observations since the 1980s have shown that these periodic bright eruptions are typical behavior for Loki. They occur about once per year and last several months. Galileo has given us our first chance to see one of these eruptions up close. 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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Highest Resolution Image Eve
…
PIA02507
Jupiter
Solid-State Imaging
| Title |
Highest Resolution Image Ever Obtained of Io |
| Original Caption Released with Image |
Click on this image for a full resolution context image (in tiff format) that corresponds to the caption below. Click here for a jpeg format image. The highest resolution image ever of Jupiter's volcanic moon Io, (the black and white image at top), was taken by NASA's Galileo spacecraft on October 10, 1999, from an altitude of 617 kilometers (417 miles). It shows an area about 7.2 kilometers (4.5 miles) long and 2.2 kilometers (1.4 miles)wide. Features as small as 9 meters (30 feet) can be discerned, providing a resolution which is 50 times better the previous best, taken by the Voyager spacecraft in 1979. The box drawn in the center image, a Galileo image of Io taken earlier in the mission, shows the area displayed in the new image at top. The three color images below show the volcanic region from a much higher altitude than the other images and follow a volcanic eruption observed by Galileo earlier in mission This new image targeted lava flows that erupted from the volcano Pillan. A complex mix of smooth and rough areas can be seen with clusters of pits and domes, many of which are the size of houses. The volcanic features are similar to those found on Earth and Mars. However, this combination of different types of lava flows has not been seen before in such a small area, demonstrating the variety of volcanic processes that continue to change the surface of Io. North is to the top of the pictures and the Sun illuminates the surface from the right. In the top and middle images the Sun is only a few degrees above the horizon, emphasizing topography. Galileo scientists estimate that the cliff on the left side of the image ranges from 3 to 10 meters (10 to 33 feet) high. In 1997 Galileo caught Pillan in the process of erupting. The explosion blanketed an area 400 kilometers (250 miles) in diameter with ash as seen in the series of three color images at the bottom. These images show the changes that have occurred at Pillan over the last three years (previous release) [ http://photojournal.jpl.nasa.gov/catalog/PIA02501 ]. Pillan is the new dark spot in middle color frame and the big, red ring seen in all three images is formed by the plume from the nearby volcano Pele. Galileo's camera and near-infrared mapping spectrometer measured the temperatures of the lavas during the eruption and found that they were hotter than any known eruption on Earth in the last two billion years. 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://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
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Highest Resolution Image Eve
…
PIA02507
Jupiter
Solid-State Imaging
| Title |
Highest Resolution Image Ever Obtained of Io |
| Original Caption Released with Image |
Click on this image for a full resolution context image (in tiff format) that corresponds to the caption below. Click here for a jpeg format image. The highest resolution image ever of Jupiter's volcanic moon Io, (the black and white image at top), was taken by NASA's Galileo spacecraft on October 10, 1999, from an altitude of 617 kilometers (417 miles). It shows an area about 7.2 kilometers (4.5 miles) long and 2.2 kilometers (1.4 miles)wide. Features as small as 9 meters (30 feet) can be discerned, providing a resolution which is 50 times better the previous best, taken by the Voyager spacecraft in 1979. The box drawn in the center image, a Galileo image of Io taken earlier in the mission, shows the area displayed in the new image at top. The three color images below show the volcanic region from a much higher altitude than the other images and follow a volcanic eruption observed by Galileo earlier in mission This new image targeted lava flows that erupted from the volcano Pillan. A complex mix of smooth and rough areas can be seen with clusters of pits and domes, many of which are the size of houses. The volcanic features are similar to those found on Earth and Mars. However, this combination of different types of lava flows has not been seen before in such a small area, demonstrating the variety of volcanic processes that continue to change the surface of Io. North is to the top of the pictures and the Sun illuminates the surface from the right. In the top and middle images the Sun is only a few degrees above the horizon, emphasizing topography. Galileo scientists estimate that the cliff on the left side of the image ranges from 3 to 10 meters (10 to 33 feet) high. In 1997 Galileo caught Pillan in the process of erupting. The explosion blanketed an area 400 kilometers (250 miles) in diameter with ash as seen in the series of three color images at the bottom. These images show the changes that have occurred at Pillan over the last three years (previous release) [ http://photojournal.jpl.nasa.gov/catalog/PIA02501 ]. Pillan is the new dark spot in middle color frame and the big, red ring seen in all three images is formed by the plume from the nearby volcano Pele. Galileo's camera and near-infrared mapping spectrometer measured the temperatures of the lavas during the eruption and found that they were hotter than any known eruption on Earth in the last two billion years. 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://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found at URLhttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ]. |
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Loki as viewed by Galileo NI
…
PIA02514
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Loki as viewed by Galileo NIMS |
| Original Caption Released with Image |
This image shows Loki, the most powerful volcano in the solar system, which has been constantly active on Jupiter's moon Io for at least 20 years. NASA's Galileo spacecraft took these images during its approach to Io on October 10, 1999. One of the spacecraft's instruments, the near infrared mapping spectrometer, was used to capture this observation. The instrument detects heat from objects in the infrared wavelengths not visible to the naked eye. Loki is a volcanic caldera about 200 kilometers (124 miles) across, nearly four times the width of the Yellowstone caldera on Earth. On the left side of the top image is a picture taken in visible light wavelengths by Galileo's camera showing the context of the NIMS image on the right. This thermal map taken by the spectrometer at 4.7 microns shows that heat is being emitted from the areas that are dark in the camera image. The bottom image shows additional spectrometer data obtained as the platform that holds the instrument on the spacecraft was moving toward the next target. This repositioned scan (shown as the zig-zag pattern) allowed the spectrometer to sample the warm, dark floor of the Loki caldera and the cold regions outside the caldera. The thermal map shows that the dark materials on the floor of Loki are cooling lava, near zero degrees Celsius(32 Fahrenheit). This substantially hotter than Io's surface temperature of about -180 degrees Celsius (-300 Fahrenheit). In previous observations, higher lava temperatures have been measured by the spectrometer at Loki, with temperatures similar to those of basaltic lava on Earth. The lighter, colored area in the camera image, which appears to be an island, is cold, which means it has not been active recently. The spectrometer detects both reflected sunlight and thermal emission from hot materials on the surface. This observation was taken on Io's nightside to avoid mixing sunlight with the thermal emission from hot lavas. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995 on a mission to study the giant planet, its largest moons and its magnetic environment. JPL 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 ]. |
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Loki as viewed by Galileo NI
…
PIA02514
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Loki as viewed by Galileo NIMS |
| Original Caption Released with Image |
This image shows Loki, the most powerful volcano in the solar system, which has been constantly active on Jupiter's moon Io for at least 20 years. NASA's Galileo spacecraft took these images during its approach to Io on October 10, 1999. One of the spacecraft's instruments, the near infrared mapping spectrometer, was used to capture this observation. The instrument detects heat from objects in the infrared wavelengths not visible to the naked eye. Loki is a volcanic caldera about 200 kilometers (124 miles) across, nearly four times the width of the Yellowstone caldera on Earth. On the left side of the top image is a picture taken in visible light wavelengths by Galileo's camera showing the context of the NIMS image on the right. This thermal map taken by the spectrometer at 4.7 microns shows that heat is being emitted from the areas that are dark in the camera image. The bottom image shows additional spectrometer data obtained as the platform that holds the instrument on the spacecraft was moving toward the next target. This repositioned scan (shown as the zig-zag pattern) allowed the spectrometer to sample the warm, dark floor of the Loki caldera and the cold regions outside the caldera. The thermal map shows that the dark materials on the floor of Loki are cooling lava, near zero degrees Celsius(32 Fahrenheit). This substantially hotter than Io's surface temperature of about -180 degrees Celsius (-300 Fahrenheit). In previous observations, higher lava temperatures have been measured by the spectrometer at Loki, with temperatures similar to those of basaltic lava on Earth. The lighter, colored area in the camera image, which appears to be an island, is cold, which means it has not been active recently. The spectrometer detects both reflected sunlight and thermal emission from hot materials on the surface. This observation was taken on Io's nightside to avoid mixing sunlight with the thermal emission from hot lavas. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995 on a mission to study the giant planet, its largest moons and its magnetic environment. JPL 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 ]. |
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Loki as viewed by Galileo NI
…
PIA02514
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Loki as viewed by Galileo NIMS |
| Original Caption Released with Image |
This image shows Loki, the most powerful volcano in the solar system, which has been constantly active on Jupiter's moon Io for at least 20 years. NASA's Galileo spacecraft took these images during its approach to Io on October 10, 1999. One of the spacecraft's instruments, the near infrared mapping spectrometer, was used to capture this observation. The instrument detects heat from objects in the infrared wavelengths not visible to the naked eye. Loki is a volcanic caldera about 200 kilometers (124 miles) across, nearly four times the width of the Yellowstone caldera on Earth. On the left side of the top image is a picture taken in visible light wavelengths by Galileo's camera showing the context of the NIMS image on the right. This thermal map taken by the spectrometer at 4.7 microns shows that heat is being emitted from the areas that are dark in the camera image. The bottom image shows additional spectrometer data obtained as the platform that holds the instrument on the spacecraft was moving toward the next target. This repositioned scan (shown as the zig-zag pattern) allowed the spectrometer to sample the warm, dark floor of the Loki caldera and the cold regions outside the caldera. The thermal map shows that the dark materials on the floor of Loki are cooling lava, near zero degrees Celsius(32 Fahrenheit). This substantially hotter than Io's surface temperature of about -180 degrees Celsius (-300 Fahrenheit). In previous observations, higher lava temperatures have been measured by the spectrometer at Loki, with temperatures similar to those of basaltic lava on Earth. The lighter, colored area in the camera image, which appears to be an island, is cold, which means it has not been active recently. The spectrometer detects both reflected sunlight and thermal emission from hot materials on the surface. This observation was taken on Io's nightside to avoid mixing sunlight with the thermal emission from hot lavas. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995 on a mission to study the giant planet, its largest moons and its magnetic environment. JPL 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 ]. |
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Galileo NIMS Observes Amiran
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PIA02516
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Galileo NIMS Observes Amirani |
| Original Caption Released with Image |
This image is the highest-resolution thermal, or heat image, ever made of Amirani, a large volcano on Jupiter's moon Io. It was taken on October 10, 1999, by the near-infrared mapping spectrometer onboard NASA's Galileo spacecraft. Amirani is on the side of Io that permanently faces away from Jupiter. This image of Amirani was taken at a distance of less than 25,000 kilometers (16,000 miles). The picture scale is approximately 6.5 kilometers (4 miles) per spectrometer pixel. The center and right images show views of Amirani as seen by the spectrometer at two wavelengths, 1.0 and 4.6 microns. These images can be compared with a visible wavelength image (on the left) of the same area obtained by Galileo's camera during a previous orbit. The visible light image shows extensive lava flows and a dark-floored caldera with associated bright red deposits of material fed from the volcano. The spectrometer observation was made in daylight. The center image, taken at a wavelength of 1 micron, shows light and dark areas on the surface that can be used to line up the spectrometer data with the camera image. The image on the right shows the same area at a wavelength of 4.6 microns, which reveals the thermal emission from three separate volcanic areas. The locations of these three "hot spots" correspond to the darkest features in the camera image, reinforcing a previously held belief by Galileo scientists that there is a correlation between the dark areas and the hot spots. The three spectrometer hot spots are located at the eastern edge of the caldera at the bottom of the camera image, and two locations along the massive Amirani flows. These are most likely active lava flows on the surface. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995 on a mission to study the giant planet, its largest moons and its magnetic environment. JPL 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 ]. |
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Prometheus silicates/sulfur
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PIA02543
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Prometheus silicates/sulfur dioxide/NIMS |
| Original Caption Released with Image |
The Prometheus region of Jupiter's moon Io was imaged by the camera onboard NASA's Galileo spacecraft in July 1999 (A), and by the spacecraft's near-infrared mapping spectrometer during its October 10, 1999 flyby (B). The maps made from spectrometer data show the interplay between hot silicates on the surface and sulfur dioxide frost. Hot spots (active volcanoes) appear red in the spectrometer image (B), while sulfur dioxide frost appears blue. Hot spots known from prior observations are labeled 1(Prometheus), 5 (Camaxtli), 7 (Tupan) and 8 (Culann). Hot spots labeled 2,3, 4, and 6 were first discovered in this observation. The color bar scale in (B) represents radiance in units of solar irradiance/pi. The sulfur dioxide deposition ring around Prometheus is clearly seen in the center of the image, formed as sulfur dioxide from the currently active plume condenses away from the vent. Image (C) is a map of the relative band-depth of the sulfur dioxide absorption band that is detected by the spectrometer. Image (D) is a qualitative map of the distribution of sulfur dioxide frost on the surface. The color bar in (D) represents the fractional area covered by sulfur dioxide frost. The area shown in each panel is about 1,300 km (800 miles) across. 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 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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Loki Patera/NIMS
PIA02541
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Loki Patera/NIMS |
| Original Caption Released with Image |
This image of Loki Patera on Jupiter's volcanic moon Io shows data taken by the near-infrared mapping spectrometer onboard NASA's Galileo spacecraft during its Io flyby on October 10, 1999, superimposed on a Galileo camera image 162 kilometers (100 miles) across. The spectrometer observation has been translated into two types of temperature maps. Image A represents brightness temperatures, which are calculated by assuming that each whole pixel is at a uniform temperature. This map shows that the dark caldera floor is warm, while the light-colored island in the middle of the caldera and the terrain outside the caldera are cool. The scale on the side gives the temperatures in degrees Kelvin (280Kelvins = 45 degrees Fahrenheit, warm compared to the temperature of Io's surface, which is about 122 Kelvin, or -240 Fahrenheit). Image B represents color temperatures, which are calculated assuming the areas emitting heat can be smaller than the area of a single pixel. This map shows that the hottest temperatures (up to 460 Kelvin or 370 F) are seen in a crack running through the center of the island. The maps indicate that the floor and crack on the caldera are filled with cooling lava flows, the youngest (and therefore hottest) lavas being those in the crack. These lavas are thought to be a few months old. 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 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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Prometheus/NIMS
PIA02542
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Prometheus/NIMS |
| Original Caption Released with Image |
Volcanic "hot spots" are seen in this color temperature map of the Prometheus volcano (A) on Jupiter's moon Io created with data obtained by the near-infrared mapping spectrometer onboard NASA's Galileo spacecraft during the flyby of Io on October 10, 1999. An image obtained by Galileo's onboard camera during an earlier orbit is also shown (B). The dark area in the camera image is a lava flow about 80 kilometers (50 miles) long. Two major hot areas are seen in the spectrometer data. The eastern hot spot(right) is located near the site of a plume observed by NASA's Voyager spacecraft in 1979. The cooler western hot spot (left) coincides with the location of the current plume. This temperature map supports the idea that the main vent of the volcano is on the eastern side, and that the plume is erupting from a "rootless vent," created as the hot lava flow interacted with sulfur dioxide snow. 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 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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