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| Description |
Here on the Gallery page you can find the very latest images, videos and products from the Cassini-Huygens mission to Saturn, including the spectacular launch, spacecraft assembly and the exciting trip to Saturn. |
| Full Description |
Earth's Moon is captured in this image taken by Cassini's narrow angle camera as the spacecraft passed by on its way to its close approach to Earth of August 17, 1999. The spatial resolution scale of the image is approximately 2.3 kilometers (1.4 miles) per pixel. For higher resolution, click here. |
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An Eruption on Io
| title |
An Eruption on Io |
| date |
02.26.2007 |
| description |
The first images returned to Earth by New Horizons during its close encounter with Jupiter feature the Galilean moon Io, snapped with the Long Range Reconnaissance Imager (LORRI) at 0840 UTC on February 26, while the moon was 2.5 million miles (4 million kilometers) from the spacecraft. Io is intensely heated by its tidal interaction with Jupiter and is thus extremely volcanically active. That activity is evident in these images, which reveal an enormous dust plume, more than 150 miles high, erupting from the volcano Tvashtar. The plume appears as an umbrella-shaped feature of the edge of Io's disk in the 11 o'clock position in the right image, which is a long-exposure (20-millisecond) frame designed specifically to look for plumes like this. The bright spots at 2 o'clock are high mountains catching the setting sun, beyond them the night side of Io can be seen, faintly illuminated by light reflected from Jupiter itself. The left image is a shorter exposure -- 3 milliseconds -- designed to look at surface features. In this frame, the Tvashtar volcano shows as a dark spot, also at 11 o'clock, surrounded by a large dark ring, where an area larger than Texas has been covered by fallout from the giant eruption. This is the clearest view yet of a plume from Tvashtar, one of Io's most active volcanoes. Ground-based telescopes and the Galileo Jupiter orbiter first spotted volcanic heat radiation from Tvashtar in November 1999, and the Cassini spacecraft saw a large plume when it flew past Jupiter in December 2000. The Keck telescope in Hawaii picked up renewed heat radiation from Tvashtar in spring 2006, and just two weeks ago the Hubble Space Telescope saw the Tvashtar plume in ultraviolet images designed to support the New Horizons flyby. Most of those images will be stored onboard the spacecraft for downlink to Earth in March and April. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute |
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Solar System Montage
| Title |
Solar System Montage |
| Full Description |
This is a montage of planetary images taken by spacecraft managed by the Jet Propulsion Laboratory in Pasadena, CA. Included are (from top to bottom) images of Mercury, Venus, Earth (and Moon), Mars, Jupiter, Saturn, Uranus and Neptune. The spacecraft responsible for these images are as follows: the Mercury image was taken by Mariner 10, the Venus image by Magellan, the Earth image by Galileo, the Mars image by Viking, and the Jupiter, Saturn, Uranus and Neptune images by Voyager. Pluto is not shown as no spacecraft has yet visited it. The inner planets (Mercury, Venus, Earth, Moon, and Mars) are roughly to scale to each other, the outer planets (Jupiter, Saturn, Uranus, and Neptune) are roughly to scale to each other. Actual diameters are given below: Sun 1,390,000 km Mercury 4,879 km Venus 12,104 km Earth 12,756 km Moon 3,475 km Mars 6,794 km Jupiter 142.984 km Saturn 120,536 km Uranus 51,118 km Neptune 49,528 km Pluto 2,390 km |
| Date |
04/09/1999 |
| NASA Center |
Jet Propulsion Laboratory |
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Hubble Clicks Images of Io S
…
| Title |
Hubble Clicks Images of Io Sweeping across Jupiter |
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Hubble Makes First Direct Me
…
| Title |
Hubble Makes First Direct Measurements of Atmosphere on World Around another Star |
| General Information |
What is a Space Science Update? Major Hubble discoveries on NASA television ... Astronomers explain their Hubble discoveries at a press conference, called a Space Science Update (SSU), broadcast on NASA television. The SSU includes a question and answer session with members of the media. Back to top [ #top ] |
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Potential Source of Sulfur F
…
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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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
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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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An Eruption on Io
PIA09244
Jupiter
LORRI
| Title |
An Eruption on Io |
| Original Caption Released with Image |
The first images returned to Earth by New Horizons during its close encounter with Jupiter feature the Galilean moon Io, snapped with the Long Range Reconnaissance Imager (LORRI) at 0840 UTC on February 26, while the moon was 2.5 million miles (4 million kilometers) from the spacecraft. Io is intensely heated by its tidal interaction with Jupiter and is thus extremely volcanically active. That activity is evident in these images, which reveal an enormous dust plume, more than 150 miles high, erupting from the volcano Tvashtar. The plume appears as an umbrella-shaped feature of the edge of Io's disk in the 11 o'clock position in the right image, which is a long-exposure (20-millisecond) frame designed specifically to look for plumes like this. The bright spots at 2 o'clock are high mountains catching the setting sun, beyond them the night side of Io can be seen, faintly illuminated by light reflected from Jupiter itself. The left image is a shorter exposure -- 3 milliseconds -- designed to look at surface features. In this frame, the Tvashtar volcano shows as a dark spot, also at 11 o'clock, surrounded by a large dark ring, where an area larger than Texas has been covered by fallout from the giant eruption. This is the clearest view yet of a plume from Tvashtar, one of Io's most active volcanoes. Ground-based telescopes and the Galileo Jupiter orbiter first spotted volcanic heat radiation from Tvashtar in November 1999, and the Cassini spacecraft saw a large plume when it flew past Jupiter in December 2000. The Keck telescope in Hawaii picked up renewed heat radiation from Tvashtar in spring 2006, and just two weeks ago the Hubble Space Telescope saw the Tvashtar plume in ultraviolet images designed to support the New Horizons flyby. Most of those images will be stored onboard the spacecraft for downlink to Earth in March and April. |
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Earth-Based Observations of
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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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Bright Channelized Lava Flow
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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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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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Amirani-Maui: Longest Known
…
PIA02506
Jupiter
Solid-State Imaging
| Title |
Amirani-Maui: Longest Known Active Lava Flow in the Solar System |
| Original Caption Released with Image |
This pair of volcanic features on Jupiter's moon Io represents the longest active lava flow known to exist in our solar system. This image, one of the highest resolution pictures ever taken of Io, was obtained by NASA s Galileo spacecraft on July 3, 1999. That was during Galileo's closest pass by Io since it entered orbit around Jupiter in December 1995. The volcanic features, Amirani (right side of image) and Maui (to the left, just below the center of the image), were originally thought to be two separate volcanoes. However, Galileo images have shown that Maui is actually the active front of a lava flow that has extended westward from a vent at Amirani for more than 250 kilometers (160 miles). Observations by Galileo's near-infrared mapping spectrometer show a hotspot at Maui, so the lava must still be flowing. Other flows extend northward from the Amirani vent. White plume deposits encircle the Amirani vent and are likely to be sulfur dioxide-rich vapors that have escaped at the vent, frozen and then snowed out onto the ground. The red deposits from the dark spot southwest of the Amirani vent appear to have been blown away from the stronger Amirani plume. The red material may be produced by a form of sulfur. Amirani-Maui is more than 250 kilometers (160 miles) long. Such gigantic lava flows are found on Venus, the Earth, the Moon, and Mars. Massive eruptions on the Earth coincide with the times of major extinction events. The image, in false color, uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera, processed to enhance subtle color variations. 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. The image is centered at 23 degrees north latitude and 118 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 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 Caltech. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page athttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found athttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
|
Amirani-Maui: Longest Known
…
PIA02506
Jupiter
Solid-State Imaging
| Title |
Amirani-Maui: Longest Known Active Lava Flow in the Solar System |
| Original Caption Released with Image |
This pair of volcanic features on Jupiter's moon Io represents the longest active lava flow known to exist in our solar system. This image, one of the highest resolution pictures ever taken of Io, was obtained by NASA s Galileo spacecraft on July 3, 1999. That was during Galileo's closest pass by Io since it entered orbit around Jupiter in December 1995. The volcanic features, Amirani (right side of image) and Maui (to the left, just below the center of the image), were originally thought to be two separate volcanoes. However, Galileo images have shown that Maui is actually the active front of a lava flow that has extended westward from a vent at Amirani for more than 250 kilometers (160 miles). Observations by Galileo's near-infrared mapping spectrometer show a hotspot at Maui, so the lava must still be flowing. Other flows extend northward from the Amirani vent. White plume deposits encircle the Amirani vent and are likely to be sulfur dioxide-rich vapors that have escaped at the vent, frozen and then snowed out onto the ground. The red deposits from the dark spot southwest of the Amirani vent appear to have been blown away from the stronger Amirani plume. The red material may be produced by a form of sulfur. Amirani-Maui is more than 250 kilometers (160 miles) long. Such gigantic lava flows are found on Venus, the Earth, the Moon, and Mars. Massive eruptions on the Earth coincide with the times of major extinction events. The image, in false color, uses the near-infrared, green and violet filters (slightly more than the visible range) of the spacecraft's camera, processed to enhance subtle color variations. 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. The image is centered at 23 degrees north latitude and 118 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 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 Caltech. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page athttp://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]. Background information and educational context for the images can be found athttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
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Interpreted Lava Fountains o
…
PIA02525
Jupiter
Solid-State Imaging
| Title |
Interpreted Lava Fountains on Io |
| Original Caption Released with Image |
, 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 showed up as a white blur in the original images. With the aid of computers, the whited-out area has been reconstructed to appear as it might without the "bleeding." 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. Initial estimates of the lava temperature 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, 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. In the original images [ http://photojournal.jpl.nasa.gov/catalog/PIA02519 ], 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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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 ]. |
|
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 ]. |
|
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 ]. |
|
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 ]. |
|
Terrain near Io's south pole
…
PIA02534
Jupiter
Solid-State Imaging
| Title |
Terrain near Io's south pole, in color |
| Original Caption Released with Image |
Volcanic calderas, lava flows and cliffs are seen in this false color image of a region near the south pole of Jupiter's volcanic moon Io. It was created by combining a black and white image taken by NASA's Galileo spacecraft on February 22, 2000 with lower resolution color images taken by Galileo on July 3, 1999. The three black spots (top center and middle left) are small volcanic calderas about 10-20 kilometers (6-12 miles) in size, which are dark because their floors are covered by recent lava flows. Two of these three calderas are surrounded by diffuse dark material, which may have been thrown out of the calderas by explosive eruptions. The bright, white material is thought to be sulfur-dioxide frost and is concentrated near the cliffs in this image. It may be formed when liquid sulfur dioxide seeps out at the base of mountain scarps, vaporizes into a plume of gas, liquid and solid, and then condenses again on the surface. Part of this process, called sapping, occurs in arid environments on Earth when ground water seeps out at the bases of cliffs. The vaporization and production of plumes is much more dramatic on Io due to the lower gravitational acceleration and especially the very low atmospheric pressure. It may be one of the dominant erosion processes on Io. The mountain at the center left, named Telegonus Mensae, exhibits a number of ridges parallel to its margins. These ridges have been observed on a number of other Ionian mountains and they suggest that as the mountain ages, it is collapsing outward under the influence of gravity. The yellow lava flow at the southern end of the image appears to be fed by a dark channel that connects to a dark caldera. This is a likely candidate for a lava flow composed of sulfur (rather than silicate material). The image is centered at 53.8 degrees south latitude and 117.1 degrees west longitude and north is to the top. The higher resolution image has a resolution of 350 meters (or yards) per picture element and is illuminated from the upper left. It was taken at a range of 34,000 kilometers (21,000 miles). The color images have resolutions of 1.3 kilometers (0.81 miles) per picture element and are illuminated from almost directly behind the spacecraft. They were taken at a distance of about 130,000 kilometers (81,000 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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Eruption at Tvashtar Catena,
…
PIA02545
Jupiter
Solid-State Imaging
| Title |
Eruption at Tvashtar Catena, Io, in color |
| Original Caption Released with Image |
NASA's Galileo spacecraft caught this volcanic eruption in action on Jupiter's moon Io on November 25, 1999. This mosaic shows Tvashtar Catena, a chain of calderas, in enhanced color. It combines low resolution (1.3 kilometers, or .8 miles, per picture element) color images of Io taken on July 3, 1999 with the much higher resolution (180 meters, or 197 yards, per picture element) black and white images taken in November. The molten lava was hot enough, and therefore bright enough, to saturate, or overexpose, Galileo's camera (original image is inset in lower right corner). The bright lava curtain (a chain of lava fountains) and surface flows shown in the color image were assembled as an interpretive drawing by Galileo scientists, based on their knowledge of how the camera behaves when saturated. The lava appears to be producing fountains to heights of up to 1.5 kilometers (5,000 feet) above the surface. Several other lava flows can be seen on the floors of the calderas. The darkest flows are probably the most recent. The elongated caldera in the center of the image is almost surrounded by a mesa that is about 1 kilometer (.6 miles) high. In places the mesas margins are scalloped, which is typical of an erosional process called sapping. This occurs when fluid escapes from the base of a cliff, causing the material above it to collapse. On Earth, sapping is caused by springs of groundwater. Similar features on Mars are one of the key pieces of evidence that water flowed on Mars surface in the past. On Io, the fluid is believed to be sulfur dioxide, which should vaporize almost instantaneously when it reaches the near vacuum at Io's surface, blasting away material at the base of the cliffs. North is to the top of the image and the Sun illuminates the surface from the lower left. The high resolution black and white image was taken at a distance of 17,000 kilometers (11,000 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 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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Stereo Image of Tvashtar Cat
…
PIA02552
Jupiter
Solid-State Imaging
| Title |
Stereo Image of Tvashtar Catena, Io |
| Original Caption Released with Image |
This stereo image illustrates the topography of the Tvashtar Catena region on Jupiter's moon Io. It was created by combining two different views of Tvashtar taken by NASA's Galileo spacecraft on November 25,1999 (shown in red) and February 22, 2000 (shown in blue). A raised plateau surrounds the volcanic depression, or caldera, in the center of the image. To the northeast of the main caldera, the plateau's inner and outer margins are scalloped, which may indicate that a process called sapping is eroding them. Sapping occurs when fluid escapes from the base of a cliff, causing the material above it to collapse. Smaller calderas have formed in the floor of the main caldera. This nesting of calderas is also observed on Earth, at Kilauea in Hawaii. (The two bright red regions toward the upper left of this image, which are roughly triangular in shape, are the areas where the earlier image was overexposed by the brightness of hot lava fountains). Galileo scientists are in the process of generating topographic maps from these images. Such maps will reveal the heights and slopes of different landforms in this region, which will help scientists determine the strength and other properties, of Io's surface materials. They will also be useful in understanding the processes of uplift and erosion on Io. The picture is centered at 59 degrees north latitude and 121 degrees west longitude. North is to the top of the picture and the Sun illuminates the surface from the lower left. The observations used to make the stereo image were made at ranges of 18,000 and 34,500 kilometers (11,400 and 21,600 miles) from Io. The resolution of the stereo image is about 320 meters (350 yards) 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 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 ]. |
|
Highest resolution of lava f
…
PIA02533
Jupiter
Solid-State Imaging
| Title |
Highest resolution of lava flows on Io |
| Original Caption Released with Image |
Lava flows similar to those found in Hawaii are seen in the black and white image at top, taken by NASA's Galileo spacecraft. It is one of the highest resolution images (7 meters or 23 feet per picture element)ever obtained of Jupiter's volcanic moon Io. The two horizontal black stripes are places where data were lost during transmission to Earth. The image shows the textures of lava flows on the floor of the caldera Chaac, which is shown in false color at lower resolution (185 meters or 607 feet per pixel element) in the bottom image. Calderas are depressions caused by collapse during volcanic eruptions. The one shown here is approximately 100 kilometers (63 miles) long and 30 kilometers(19 miles) across. Using shadow lengths from the new high-resolution observations, the northeastern (upper right) scarp, or line of cliffs, has been estimated to be 2.8 kilometers (9200 feet) high. The lava flows are similar in texture to lava flows within the caldera at Hawaii's Kilauea volcano. This suggests that the floor of Chaac has been covered by a combination of lava flows and lava lakes. The light-colored material surrounding the caldera may be composed of sulfur-dioxide frost or some other sulfur-rich material on the surface of Io. Galileo scientists believe that the greenish color on the caldera floor is a form of contaminated sulfur created when sulfur-rich material escaping from volcanic vents reacts chemically with warm lava flows. The high-resolution view shows numerous lava flows. The darkest flows are thought to be the most recent because they have not been covered by the sulfurous materials which coat most of Io's surface. The top image was acquired by Galileo on February 22, 2000. It was taken at a distance of 600 kilometers (370 miles) and is centered at 11.9 degrees north latitude and 157.6 degrees west longitude. North is to the top, and the Sun illuminates the surface from the right. The color image was created by combining a black and white image taken on February 22, 2000 at a distance of 18,800 kilometers (11,700 miles)from Io with lower-resolution (1.3 kilometers or 0.81 miles per picture element) color images taken on July 3, 1999 at a distance of 130,000 kilometers (81,000 miles). The image is centered at 11.6 degrees north latitude and 157.7 degrees west longitude. North is to the top and 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 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 ]. |
|
Europa Impact Crater
PIA02561
Jupiter
Near Infrared Mapping Spectr
…
| Title |
Europa Impact Crater |
| Original Caption Released with Image |
A newly discovered, city-sized impact crater viewed by NASA's Galileo spacecraft may shed new light on the nature of the enigmatic icy surface of Jupiter's moon Europa. This false-color image reveals the scar of a past major impact of a comet or small asteroid on Europa's surface. The bright, circular feature at center right has a diameter of about 80 kilometers (50 miles), making it comparable in size to the largest cities on Earth. The area within the outer boundary of the continuous bright ring is about 5,000 square kilometers (nearly 2,000 square miles). The diameter of the darker area within the bright ring is about 29 kilometers (18 miles), which is large enough to contain both the city of San Francisco and New York's Manhattan Island, side by side. The brightest reds in this image correspond to surfaces with high proportions of relatively pure water ice, while the blue colors indicate that non-ice materials are also present. The composition of the darker materials is controversial, they may consist of minerals formed by evaporation of salty brines, or they may be rich in sulfuric acid. The bright ring is a blanket of ejecta that consists of icy subsurface material that was blasted out of the crater by the impact, while the darker area in the center may retain some of the materials from the impacting body. Further study may yield new insights about both the nature of the impactor and the surface chemistry of Europa. Europa's surface is a question of great interest at present, since an ocean of liquid water may exist beneath the icy crust, possibly providing an environment suitable for life. Geologic investigations of Europa's surface are underway, and a new spacecraft mission, the Europa Orbiter, is planned. Impact craters with diameters of 20 kilometers (12 miles) and larger are extremely rare on Europa, as of 1999 only 7 such features were known. The rarity of larger impact craters on Europa lends greater significance to the discovery of this one. Impact crater counts are often employed to estimate the ages of the exposed surfaces of planets and satellites, and the small number of craters found on Europa implies that the surface may be quite young in geological terms. Thus the discovery of this feature may provide additional insights into questions about the age and level of geological activity of Europa's surface. Impact craters are expected to form with greater frequency on the "leading" sides of satellites that always turn the same face to their primary planet, in this case, Jupiter. The process is much like the effect of running through a rainstorm. The "apex" of Europa's leading side is located on the equator at 90 degrees West longitude, only about 10 degrees removed from the feature shown. Europa's leading side does not receive a continuous bombardment by ionized particles carried along by Jupiter's rapidly rotating magnetosphere (as is the case for the trailing side), which may allow greater preservation of the chemical, signatures of the impacting object. To the east of the bright ring-like feature are two, or perhaps three, similar but less well-defined quasi-circular features, raising the possibility that this crater is one member of a catena, or chain of craters. This would lend still greater interest to this area as a potential target for focused investigations by later missions such as the Europa Orbiter. The near-infrared mapping spectrometer on board Galileo obtained this image on May 31,1998, during that spacecraft's 15th orbital encounter with Europa. The image data was returned to Earth in several segments during both the 15th and the 16th orbital periods. Merging and processing of the full data set was accomplished in 1999. Analysis and interpretation are ongoing. Galileo has been orbiting Jupiter and its moons since December 1995. Its primary mission ended in December 1997, and after that Galileo successfully completed a two-year extended mission. The spacecraft is in the midst of yet another extended journey called the Galileo Millennium Mission. More information about the Galileo mission is available at:http://galileo.jpl.nasa.gov [ http://galileo.jpl.nasa.gov ]JPL manages Galileo for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology in Pasadena. |
|
Eruption at Tvashtar Catena
…
PIA02584
Jupiter
Solid-State Imaging
| Title |
Eruption at Tvashtar Catena on Io |
| Original Caption Released with Image |
. 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., This pair of images taken by NASA's Galileo spacecraft captures a dynamic eruption at Tvashtar Catena, a chain of volcanic bowls on Jupiter's moon Io. They show a change in the location of hot lava over a period of a few months in 1999 and early 2000. The image on the left uses data obtained on Nov. 26 and July 3, 1999, at resolutions of 183 meters (600 feet) and 1.3 kilometers (0.8 miles) per pixel, respectively. The red and yellow lava flow itself is an illustration based upon imaging data. The image on the right is a composite using a five-color observation made on Feb. 22, 2000, at 315 meters (1030 feet) per pixel. These are among the most fortuitous observations made by Galileo because this style of volcanism is too unpredictable and short-lived to plan to photograph. Short-lived bursts of volcanic activity on Io had been previously detected from Earth-based observations, but interpreting the style of volcanic activity from those lower-resolution views was highly speculative. These Galileo observations confirm hypotheses that the initial, intense thermal output comes from active lava fountains. Galileo's high-resolution observations of volcanic activity on Io have also confirmed other hypotheses based on earlier, low-resolution data. These include interpretations of slowly spreading lava flows at Prometheus and Amirani and an active lava lake at Pele. These tests of earlier hypotheses increase scientists' confidence in interpreting volcanic activity seen in low-resolution remote sensing data of Earth as well as Io. However, these data are still of insufficient resolution to adequately test the more quantitative models that have been applied to volcanic eruptions on Earth and Io. These images also show other geologic features on Io, such as the scalloped margins of the plateau to the northeast of the active lavas. These margins appear to have formed by sapping, a process usually associated with springs of water. Liquid sulfur dioxide might be the fluid responsible for sapping on Io. A better understanding of sapping on Io will influence how scientists interpret similar features on Mars(where the viability of carbon dioxide or water as the sapping fluid remains controversial). The individual images in this composite can be viewed separately in the PIA02545 [ http://photojournal.jpl.nasa.gov/catalog/PIA02545 ] (left hand image) and PIA02550 [ http://photojournal.jpl.nasa.gov/catalog/PIA02550 ] (right hand image) photojournal entries. Images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found athttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
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Amirani's Big Lava Flow on I
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PIA02585
Jupiter
Solid-State Imaging
| Title |
Amirani's Big Lava Flow on Io |
| Original Caption Released with Image |
. 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., These images from NASA's Galileo spacecraft show changes in the largest active field lava flows in the solar system, the Amirani lava flow on Jupiter's moon Io. Scientists have identified 23 distinct new flows by comparing the two images taken 134 days apart, on Oct. 11, 1999, and Feb. 22, 2000. The Amirani lava-flow field spans more than 300 kilometers (190 miles). Individual flows within it are each several kilometers or miles long, which is about the size of the entire active eruption on Kilauea, Hawaii. In total, the new lava flows at Amirani covered about 620square kilometers (240 square miles) of Io in less than five months. By comparison, Kilauea covered only about 10 square kilometers (4 square miles) in the same time. Amirani is huge even when compared to other Ionian lava flows: The Prometheus lava flow field covered only about 60square kilometers (24 square miles) during this time. Galileo scientists are studying Amirani to understand how such large lava flows are created. The last eruption this size on Earth happened about 15 million years ago along the Columbia River in what is now the state of Washington. Many scientists thought that such long lava flows were formed in violent volcanic outbursts. However, the eruption observed at Amirani is relatively calm, despite the fact that over 100tons of lava are disgorged every second. Galileo's observations of Io indicate that huge, ancient lava flows on the Earth, such as the Columbia River flood basalts, could also have formed in relatively tranquil eruptions. The color image on the left is a composite of black-and-white images collected on Feb. 22, 2000, at a resolution of 210 meters (690 feet) per picture element, and color images collected on June 30, 1999, at 1.3 kilometers (0.8 mile) per picture element. The white boxes and arrows show the locations of the areas analyzed in detail on the right. The left-hand pair of black-and-white images, labeled I24, are parts of a mosaic collected on Oct. 11, 1999, at 500 meters (550 yards) per picture element. The center pair of images, labeled I27, shows what the same areas looked like on Feb. 22, 2000. These later images are about twice as sharp as the earlier images, making some features that did not change appear crisper. In order to demonstrate the real changes, the I27 images were divided by the I24 images, producing the pair of ratio images on the right. The new dark lava that erupted between October 1999 and February 2000 has been highlighted in red. Images and data received from Galileo are posted on the Galileo mission home page at http://www.jpl.nasa.gov/galileo [ http://www.jpl.nasa.gov/galileo ]. Background information and educational context for the images can be found athttp://www.jpl.nasa.gov/galileo/sepo [ http://www.jpl.nasa.gov/galileo/sepo ] |
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