PIA00839: Callisto Asgard Region as Viewed by NIMS
Target Name: Callisto
Is a satellite of: Jupiter
Mission: Galileo
Spacecraft: Galileo Orbiter
Instrument: Near Infrared Mapping Spectrometer
Product Size: 1065 x 863 pixels (width x height)
Produced By: JPL
Producer ID: MRPS77787
Addition Date: 1998-03-26
Primary Data Set: Galileo EDRs
Full-Res TIFF: PIA00839.tif (61.68 kB)
Full-Res JPEG: PIA00839.jpg (36.83 kB)

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Original Caption Released with Image:

This view of Callisto's Asgard multi-ring structure was taken by the Near Infrared Mapping Spectrometer (NIMS) 90 minutes before closest approach. The false color image shows surface compositional differences, white=more ice, blue=less ice. The large bright/white area is the palimpsest or center of Asgard. The smaller bright area is Tornasuk, a crater with a diameter of about 70 km.

The infrared spectrum shows that Tornasuk exhibits a greater abundance of water ice compared with the surrounding region. This may be due to impact excavation revealing a more ice-rich subsurface and suggesting that the darker material is a relatively thin surface covering. This covering could be either impact debris material or a lag deposit of existing material from which the ice has evaporated away.

The Jet Propulsion Laboratory, Pasadena, CA manages the 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/sepo.

Image Credit:
NASA/JPL

Image Addition Date:
1998-03-26