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Collection:
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NASA Planetary Photo Journal Collection
Collection
NASA Planetary Photo Journal Collection
Collection
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Title:
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Io's Loki in Infrared: Hot Edge
Title
Io's Loki in Infrared: Hot Edge
Title
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Original Caption Released with Image:
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High temperatures observed by NASA's Galileo spacecraft along the western edge of the Loki volcano on Jupiter's moon Io may indicate freshly exposed material at the shore of a lava lake. Two temperature maps of the southern portion of Loki show hot (lower right) and hotter (upper right) features based on infrared-wavelength observations during an Oct. 16, 2001, flyby of Io. For context, they are shown beside a visible-wavelength picture (left) of the area taken during an earlier flyby. Loki is the most powerful volcano on Io. It has been active since at least 1979, when it was discovered by NASA's Voyager mission. Loki's dark volcanic crater, called a caldera, surrounds a light-colored island, as seen in the camera image (left). Previous observations by Galileo's instruments have shown that active lavas and still-cooling lava flows cover the floor of the caldera. In contrast, the island is cold and has no volcanic activity except in a narrow dark region that may be a crack or valley. Current volcanic activity appears in the two temperature maps from Galileo's near-infrared mapping spectrometer instrument. The lower right image shows where the surface is glowing at an infrared wavelength of 4.4 microns, with the yellow-orange coding correlated to temperatures of about 360 degrees Kelvin (188 Fahrenheit) and the reddish coding correlated to temperatures of about 430 Kelvin (314 Fahrenheit). The upper right image is at a wavelength of 2.5 microns, with the white streak correlated to temperatures of roughly 840 Kelvin (1,052 Fahrenheit). Each picture element averages the characteristics of an area about 2 kilometers (1.2 miles) across; smaller patches may be hundreds of degrees higher. Loki has puzzled scientists trying to determine what type of volcano it is. One idea holds it is an active lava lake with molten material under the crust. A competing view is it is a caldera whose floor is continuously flooded by lavas in successive flows. The concentration of higher temperatures along the western edge in the 2.5 micron map favors the lava lake idea. The cooler crust of molten lava lakes on Earth, such as on Hawaii's Kilauea volcano, tends to drift outward and hit against the caldera wall. This causes the crust next to the wall to break up, exposing hotter material from underneath. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the spacecraft and its discoveries is available on the Galileo home page at http://galileo.jpl.nasa.gov.
Original_Caption_Rel eased_with_Image
High temperatures observed by NASA's Galileo spacecraft along the western edge of the Loki volcano on Jupiter's moon Io may indicate freshly exposed material at the shore of a lava lake. Two temperature maps of the southern portion of Loki show hot (lower right) and hotter (upper right) features based on infrared-wavelength observations during an Oct. 16, 2001, flyby of Io. For context, they are shown beside a visible-wavelength picture (left) of the area taken during an earlier flyby. Loki is the most powerful volcano on Io. It has been active since at least 1979, when it was discovered by NASA's Voyager mission. Loki's dark volcanic crater, called a caldera, surrounds a light-colored island, as seen in the camera image (left). Previous observations by Galileo's instruments have shown that active lavas and still-cooling lava flows cover the floor of the caldera. In contrast, the island is cold and has no volcanic activity except in a narrow dark region that may be a crack or valley. Current volcanic activity appears in the two temperature maps from Galileo's near-infrared mapping spectrometer instrument. The lower right image shows where the surface is glowing at an infrared wavelength of 4.4 microns, with the yellow-orange coding correlated to temperatures of about 360 degrees Kelvin (188 Fahrenheit) and the reddish coding correlated to temperatures of about 430 Kelvin (314 Fahrenheit). The upper right image is at a wavelength of 2.5 microns, with the white streak correlated to temperatures of roughly 840 Kelvin (1,052 Fahrenheit). Each picture element averages the characteristics of an area about 2 kilometers (1.2 miles) across; smaller patches may be hundreds of degrees higher. Loki has puzzled scientists trying to determine what type of volcano it is. One idea holds it is an active lava lake with molten material under the crust. A competing view is it is a caldera whose floor is continuously flooded by lavas in successive flows. The concentration of higher temperatures along the western edge in the 2.5 micron map favors the lava lake idea. The cooler crust of molten lava lakes on Earth, such as on Hawaii's Kilauea volcano, tends to drift outward and hit against the caldera wall. This causes the crust next to the wall to break up, exposing hotter material from underneath. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo mission for NASA's Office of Space Science, Washington, D.C. Additional information about the spacecraft and its discoveries is available on the Galileo home page at http://galileo.jpl.nasa.gov. Original Caption Released with Image
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Addition Date:
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2001-11-27
Addition_Date
2001-11-27
Addition Date
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Image Credit:
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NASA/JPL
Image_Credit
NASA/JPL
Image Credit
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Produced By:
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JPL
Produced_By
JPL
Produced By
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Mission:
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Galileo
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Spacecraft:
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Galileo Orbiter
Spacecraft
Galileo Orbiter
Spacecraft
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Target Name:
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Io
Target_Name
Io
Target Name
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Is a satellite of:
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Jupiter
Is_a_satellite_of
Jupiter
Is a satellite of
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Instrument:
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Near Infrared Mapping Spectrometer
Instrument
Near Infrared Mapping Spectrometer
Instrument
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Product Size:
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595 samples x 415 lines
Product_Size
595 samples x 415 lines
Product Size
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Primary Data Set:
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Galileo EDRs
Primary_Data_Set
Galileo EDRs
Primary Data Set
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facet_what:
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Crater
facet_what
Crater
facet_what
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facet_what:
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Moon
facet_what
Moon
facet_what
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facet_what:
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Jupiter
facet_what
Jupiter
facet_what
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facet_what:
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Voyager
facet_what
Voyager
facet_what
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facet_what:
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Earth
facet_what
Earth
facet_what
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facet_what:
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Galileo
facet_what
Galileo
facet_what
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facet_what:
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Galileo Orbiter
facet_what
Galileo Orbiter
facet_what
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facet_what:
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Spectrometer
facet_what
Spectrometer
facet_what
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facet_what:
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Io
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facet_what:
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Near Infrared Mapping Spectrometer (NIMS)
facet_what
Near Infrared Mapping Spectrometer (NIMS)
facet_what
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facet_where:
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Jet Propulsion Laboratory
facet_where
Jet Propulsion Laboratory
facet_where
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facet_where:
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Jupiter
facet_where
Jupiter
facet_where
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facet_where:
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California
facet_where
California
facet_where
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facet_where:
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Washington
facet_where
Washington
facet_where
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facet_where:
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Hawaii
facet_where
Hawaii
facet_where
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facet_where:
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Jet Propulsion Laboratory (JPL)
facet_where
Jet Propulsion Laboratory (JPL)
facet_where
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facet_where:
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Washington, D.C.
facet_where
Washington, D.C.
facet_where
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Image #:
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PIA02595
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UID:
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SPD-PHOTJ-PIA02595
UID
SPD-PHOTJ-PIA02595
UID
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orignial url:
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orignial_url
orignial url
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