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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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Europa's Frozen Surface
Title
Europa's Frozen Surface
Title
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Original Caption Released with Image:
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Europa, a moon of Jupiter, appears as a thick crescent in this enhanced-color image from NASA's Galileo spacecraft, which has been orbiting Jupiter since 1995. The view combines images taken in violet, green and near-infrared filters in 1998 and 1995. The colors have been stretched to show the subtle differences in materials that cover the icy surface of Europa. Reddish linear features are some of the cracks and ridges, thousands of kilometers long, which are caused by the tides raised by the gravitational pull of Jupiter. Mottled, reddish "chaotic terrain" exists where the surface has been disrupted and ice blocks have moved around. The red material at the ridges and chaotic terrain is a non-ice contaminant and could be salts brought up from a possible ocean beneath Europa's frozen surface. Also visible are a few circular features, which are small impact craters. Europa's surface has very few craters, indicating that recent or current geologic activity has removed the traces of older impacts. The paucity of craters, coupled with other evidence, has led scientists to surmise that there could be an ocean of liquid water beneath Europa's surface. Where there is water, there could be life. This is why Europa is a target of current interest for study of the possibility of non-Earth life. A follow-up spacecraft to Galileo will be Europa Orbiter, which should determine whether or not Europa has an ocean. While at the University of Arizona, Tucson, Dr. Cynthia Phillips used this image in a detailed search for current geologic activity on Europa. Phillips is currently with the SETI Institute, Mountain View, Calif. For a study published in the Journal of Geophysical Research -- Planets last year, she compared the frames that make up this image with similar images taken in 1979 by the Voyager spacecraft and found no sign of changes due to geologic activity. That suggests a minimum surface age for Europa of about 30 million years, though the result does not rule out current geologic activity altogether, as the study was limited by the resolution of 2 kilometers (1.6 miles) or more per pixel in this image and the Voyager images. Future images by Europa Orbiter may allow a search for smaller-scale changes on Europa's surface. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Voyager missions 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.
Original_Caption_Rel eased_with_Image
Europa, a moon of Jupiter, appears as a thick crescent in this enhanced-color image from NASA's Galileo spacecraft, which has been orbiting Jupiter since 1995. The view combines images taken in violet, green and near-infrared filters in 1998 and 1995. The colors have been stretched to show the subtle differences in materials that cover the icy surface of Europa. Reddish linear features are some of the cracks and ridges, thousands of kilometers long, which are caused by the tides raised by the gravitational pull of Jupiter. Mottled, reddish "chaotic terrain" exists where the surface has been disrupted and ice blocks have moved around. The red material at the ridges and chaotic terrain is a non-ice contaminant and could be salts brought up from a possible ocean beneath Europa's frozen surface. Also visible are a few circular features, which are small impact craters. Europa's surface has very few craters, indicating that recent or current geologic activity has removed the traces of older impacts. The paucity of craters, coupled with other evidence, has led scientists to surmise that there could be an ocean of liquid water beneath Europa's surface. Where there is water, there could be life. This is why Europa is a target of current interest for study of the possibility of non-Earth life. A follow-up spacecraft to Galileo will be Europa Orbiter, which should determine whether or not Europa has an ocean. While at the University of Arizona, Tucson, Dr. Cynthia Phillips used this image in a detailed search for current geologic activity on Europa. Phillips is currently with the SETI Institute, Mountain View, Calif. For a study published in the Journal of Geophysical Research -- Planets last year, she compared the frames that make up this image with similar images taken in 1979 by the Voyager spacecraft and found no sign of changes due to geologic activity. That suggests a minimum surface age for Europa of about 30 million years, though the result does not rule out current geologic activity altogether, as the study was limited by the resolution of 2 kilometers (1.6 miles) or more per pixel in this image and the Voyager images. Future images by Europa Orbiter may allow a search for smaller-scale changes on Europa's surface. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Galileo and Voyager missions 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. Original Caption Released with Image
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Addition Date:
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2001-06-22
Addition_Date
2001-06-22
Addition Date
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Image Credit:
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NASA/JPL/University of Arizona
Image_Credit
NASA/JPL/University of Arizona
Image Credit
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Produced By:
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University of Arizona
Produced_By
University of Arizona
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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Europa
Target_Name
Europa
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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Solid-State Imaging
Instrument
Solid-State Imaging
Instrument
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Product Size:
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536 samples x 900 lines
Product_Size
536 samples x 900 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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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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Solid-State Imaging
facet_what
Solid-State Imaging
facet_what
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facet_what:
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Europa
facet_what
Europa
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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Arizona
facet_where
Arizona
facet_where
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facet_where:
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Europa
facet_where
Europa
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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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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facet_when:
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1979
facet_when
1979
facet_when
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facet_when:
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1998
facet_when
1998
facet_when
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facet_when_year:
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1979
facet_when_year
1979
facet_when_year
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facet_when_year:
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1998
facet_when_year
1998
facet_when_year
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Image #:
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PIA02590
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UID:
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SPD-PHOTJ-PIA02590
UID
SPD-PHOTJ-PIA02590
UID
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orignial url:
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orignial_url
orignial url
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