Numerous blue-green fractures can be seen in this false-color mosaic taken
during Cassini's second close flyby of Enceladus, on March 9, 2005.
The mosaic shows the anti-Saturnian hemisphere of Enceladus -- the side
that always faces away from Saturn. This region contains a number of
tectonic and impact features and shows how these two geologic forces
interact on Enceladus. The center left portion of this mosaic is dominated
by Diyar Planitia. Like Sarandib Planitia observed in the previous
Enceladus flyby, the region is characterized by low ridges and troughs.
Throughout this hemisphere, fractures of all sizes disrupt the previously
existing cratered terrain and even the comparatively youthful Diyar
Planitia.
Many of the younger fractures have blue-green walls, revealing
coarse-grained water ice in the top layers of Enceladus' lithosphere,
compared to the fine-grained ice that coats much of Enceladus' surface.
The blue-green color is very similar to the coatings surrounding the south
polar "tiger stripes" (these appear greener than the features in the south
polar mosaic released in 2005 (see PIA07800) due to the use of clear-filter
images, instead of green, in that mosaic).
A higher resolution cropped section of this mosaic is available in PIA08355.
This mosaic consists of 25 false-color footprints (75 images total) taken
by the Cassini spacecraft's narrow-angle camera. The mosaic uses an
ultraviolet filter centered at 338 nanometers for blue, a green filter
centered at 568 nanometers for green and a near-infrared filter centered
at 930 nanometers for red -- thus covering a wider spectrum region than
the human eye. To create a single, full-disk mosaic, the images were
reprojected into an orthographic projection centered at 1.5 degrees south
latitude, 204 degrees west longitude with a pixel scale of 90 meters (295
feet) per pixel. The black strip seen at the top of the mosaic is an
unfilled seam between two images.
The original images were taken from distances ranging from 4,300 to 31,800
kilometers (2,670 to 19,760 miles). The images have a phase, or
sun-Enceladus-spacecraft, angle of 45 degrees.
The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory,
a division of the California Institute of Technology in Pasadena, manages
the mission for NASA's Science Mission Directorate, Washington, D.C. The
Cassini orbiter and its two onboard cameras were designed, developed and
assembled at JPL. The imaging operations center is based at the Space
Science Institute in Boulder, Colo.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov/home/index.cfm. The Cassini imaging team
homepage is at http://ciclops.org.