|
Collection:
|
|
NASA Planetary Photo Journal Collection
Collection
NASA Planetary Photo Journal Collection
Collection
|
|
Title:
|
|
Close-up of Zamama, Io (color)
Title
Close-up of Zamama, Io (color)
Title
|
|
Original Caption Released with Image:
|
A volcano named Zamama on Jupiter's moon Io has recently changed in appearance as seen in this pair of images of Io acquired by NASA's Galileo spacecraft as it approached Io in preparation for a close flyby. The false color images use the near-infrared, green and violet filters (a range greater than the range the human eye can see) of the spacecraft's camera, processed to slightly enhance Io's naturally vibrant colors. The image on the left was acquired in March 1998 during Galileo's 14th orbit and the image on the right was collected in July 1999 during the 21st orbit. The July 1999 images are the highest resolution images of Io taken by Galileo since it entered orbit around Jupiter in December 1995. Zamama formed
Original_Caption_Rel eased_with_Image
A volcano named Zamama on Jupiter's moon Io has recently changed in appearance as seen in this pair of images of Io acquired by NASA's Galileo spacecraft as it approached Io in preparation for a close flyby. The false color images use the near-infrared, green and violet filters (a range greater than the range the human eye can see) of the spacecraft's camera, processed to slightly enhance Io's naturally vibrant colors. The image on the left was acquired in March 1998 during Galileo's 14th orbit and the image on the right was collected in July 1999 during the 21st orbit. The July 1999 images are the highest resolution images of Io taken by Galileo since it entered orbit around Jupiter in December 1995. Zamama formed Original Caption Released with Image
|
|
Original Caption Released with Image:
|
|
during the time period between the flybys of NASA's Voyager spacecraft in 1979 and Galileo's first images of Io taken in 1996. Based on these images, Galileo scientists suspect that the dark lava is erupting from a crack in the ground. Analysis of combined data from Galileo's camera and its near-infrared mapping spectrometer instrument showed that the lava erupting at Zamama must be hotter than 830 C (1,500 F). Because this too hot to be sulfur, scientists believe the lava may contain silicates.
The most dramatic difference between these two images is that the volcanic plume that was active in March 1998 and earlier had stopped erupting by July 1999. The rising core of the umbrella-shaped plume can be seen in the 1998 image as a bluish spot in the center of the dark lava. Dark and bright spokes of material falling away from the core are also visible. When it falls back to the ground, this material makes circular white and yellow deposits around the vent. The white deposits are thought to be composed mostly of sulfur dioxide that left the volcanic vent as a vapor and condensed into a frost as the gases expanded into the near-vacuum of Io's atmosphere. Interestingly, red plume material has only been deposited to the northwest. This might be the result of small pockets of boiling sulfur that produce droplets of red sulfur blown outward by the main plume. Most of the other, more subtle color variations around Zamama are likely to be the result of different lighting conditions that existed when the two images were taken.
A high-resolution (20 to 40 meters or 66 to 130 feet per picture element) strip of images across Zamama is planned during Galileo's flyby of Io on October 10, 1999. These images will be useful in determining how lava moves on Io's surface, specifically whether the lava travels in open rivers of lava or in well-insulated lava tubes. The size and shape of features on the lava flows can be used to estimate properties of the lava that will provide vital clues to the still unanswered question about what kind of lava is erupting from Io's volcanoes.
North is to the top of the pictures. The images are centered at 17.4 degrees north latitude and 173 degrees west longitude. The image on the left was taken on March 1998 at a range of 294,000 kilometers (183,000 miles) and has a resolution of 3 kilometers (2 miles) per picture element. The Sun illuminates the surface from the right. The image on the right was taken in July 1999 at a distance of about 130,000 kilometers (81,000 miles) and has a resolution of 1.3 kilometers or 0.8 miles per picture element. The Sun illuminates the surface from almost directly behind the spacecraft.
The Jet Propulsion Laboratory, Pasadena, CA, manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission
Original_Caption_Rel eased_with_Image
during the time period between the flybys of NASA's Voyager spacecraft in 1979 and Galileo's first images of Io taken in 1996. Based on these images, Galileo scientists suspect that the dark lava is erupting from a crack in the ground. Analysis of combined data from Galileo's camera and its near-infrared mapping spectrometer instrument showed that the lava erupting at Zamama must be hotter than 830 C (1,500 F). Because this too hot to be sulfur, scientists believe the lava may contain silicates.
The most dramatic difference between these two images is that the volcanic plume that was active in March 1998 and earlier had stopped erupting by July 1999. The rising core of the umbrella-shaped plume can be seen in the 1998 image as a bluish spot in the center of the dark lava. Dark and bright spokes of material falling away from the core are also visible. When it falls back to the ground, this material makes circular white and yellow deposits around the vent. The white deposits are thought to be composed mostly of sulfur dioxide that left the volcanic vent as a vapor and condensed into a frost as the gases expanded into the near-vacuum of Io's atmosphere. Interestingly, red plume material has only been deposited to the northwest. This might be the result of small pockets of boiling sulfur that produce droplets of red sulfur blown outward by the main plume. Most of the other, more subtle color variations around Zamama are likely to be the result of different lighting conditions that existed when the two images were taken.
A high-resolution (20 to 40 meters or 66 to 130 feet per picture element) strip of images across Zamama is planned during Galileo's flyby of Io on October 10, 1999. These images will be useful in determining how lava moves on Io's surface, specifically whether the lava travels in open rivers of lava or in well-insulated lava tubes. The size and shape of features on the lava flows can be used to estimate properties of the lava that will provide vital clues to the still unanswered question about what kind of lava is erupting from Io's volcanoes.
North is to the top of the pictures. The images are centered at 17.4 degrees north latitude and 173 degrees west longitude. The image on the left was taken on March 1998 at a range of 294,000 kilometers (183,000 miles) and has a resolution of 3 kilometers (2 miles) per picture element. The Sun illuminates the surface from the right. The image on the right was taken in July 1999 at a distance of about 130,000 kilometers (81,000 miles) and has a resolution of 1.3 kilometers or 0.8 miles per picture element. The Sun illuminates the surface from almost directly behind the spacecraft.
The Jet Propulsion Laboratory, Pasadena, CA, manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology, Pasadena, CA.
This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission
Original Caption Released with Image
|
|
Original Caption Released with Image:
|
Original_Caption_Rel eased_with_Image
Original Caption Released with Image
|
|
Addition Date:
|
|
1999-10-08
Addition_Date
1999-10-08
Addition Date
|
|
Produced By:
|
|
University of Arizona
Produced_By
University of Arizona
Produced By
|
|
Mission:
|
|
Galileo
|
|
Spacecraft:
|
|
Galileo Orbiter
Spacecraft
Galileo Orbiter
Spacecraft
|
|
Target Name:
|
|
Io
Target_Name
Io
Target Name
|
|
Is a satellite of:
|
|
Jupiter
Is_a_satellite_of
Jupiter
Is a satellite of
|
|
Instrument:
|
|
Solid-State Imaging
Instrument
Solid-State Imaging
Instrument
|
|
Product Size:
|
|
967 samples x 395 lines
Product_Size
967 samples x 395 lines
Product Size
|
|
Primary Data Set:
|
|
Galileo EDRs
Primary_Data_Set
Galileo EDRs
Primary Data Set
|
|
Producer ID:
|
|
P50597 MRPS95301
Producer_ID
P50597 MRPS95301
Producer ID
|
|
facet_what:
|
|
Sun
facet_what
Sun
facet_what
|
|
facet_what:
|
|
Moon
facet_what
Moon
facet_what
|
|
facet_what:
|
|
Jupiter
facet_what
Jupiter
facet_what
|
|
facet_what:
|
|
Voyager
facet_what
Voyager
facet_what
|
|
facet_what:
|
|
Galileo
facet_what
Galileo
facet_what
|
|
facet_what:
|
|
Galileo Orbiter
facet_what
Galileo Orbiter
facet_what
|
|
facet_what:
|
|
Solid-State Imaging
facet_what
Solid-State Imaging
facet_what
|
|
facet_what:
|
|
Spectrometer
facet_what
Spectrometer
facet_what
|
|
facet_what:
|
|
Io
|
|
facet_where:
|
|
Jet Propulsion Laboratory
facet_where
Jet Propulsion Laboratory
facet_where
|
|
facet_where:
|
|
Jupiter
facet_where
Jupiter
facet_where
|
|
facet_where:
|
|
Arizona
facet_where
Arizona
facet_where
|
|
facet_where:
|
|
California
facet_where
California
facet_where
|
|
facet_where:
|
|
Washington
facet_where
Washington
facet_where
|
|
facet_where:
|
|
Jet Propulsion Laboratory (JPL)
facet_where
Jet Propulsion Laboratory (JPL)
facet_where
|
|
facet_when:
|
|
1979
facet_when
1979
facet_when
|
|
facet_when:
|
|
1996
facet_when
1996
facet_when
|
|
facet_when:
|
|
December 1995
facet_when
December 1995
facet_when
|
|
facet_when:
|
|
March 1998
facet_when
March 1998
facet_when
|
|
facet_when:
|
|
July 1999
facet_when
July 1999
facet_when
|
|
facet_when:
|
|
October 10, 1999
facet_when
October 10, 1999
facet_when
|
|
facet_when_year:
|
|
1979
facet_when_year
1979
facet_when_year
|
|
facet_when_year:
|
|
1999
facet_when_year
1999
facet_when_year
|
|
facet_when_year:
|
|
1995
facet_when_year
1995
facet_when_year
|
|
facet_when_year:
|
|
1996
facet_when_year
1996
facet_when_year
|
|
facet_when_year:
|
|
1998
facet_when_year
1998
facet_when_year
|
|
Image #:
|
|
PIA02504
|
|
UID:
|
|
SPD-PHOTJ-PIA02504
UID
SPD-PHOTJ-PIA02504
UID
|
|
orignial url:
|
orignial_url
orignial url
|
