During a close flyby of Titan on March 31, 2005, Cassini's cameras got
their best view to date of the region east of the bright Xanadu Regio.
This mosaic consists of several frames taken by the narrow-angle camera
(smaller frames) put together with an image taken by the wide-angle
camera filling in the background. It reveals new detail of dark expanses
and the surrounding brighter terrain.
Some of the features seen here are reminiscent of those seen elsewhere on
Titan, but the images also reveal new features, which Cassini scientists
are working to understand.
In the center of the image (and figure A at bottom) lies a bright area
completely surrounded by darker material. The northern boundary of the
bright "island" is relatively sharp and has a jagged profile, resembling
the now-familiar boundary on the western side of Xanadu (see PIA06159).
The profile of the southern boundary is similar. However, streamers of
bright material extend southeastward into the dark terrain. At the eastern
end of the bright "island" lies a region with complex interconnected dark
and bright regions (see figure B).
To the south, the bright terrain is cut by fairly straight dark lines.
Their linearity and apparently angular intersections suggest a tectonic
influence, similar to features in seen in the bright terrain west of
Xanadu (see PIA06158).
The camera's near-infrared observations cover ground that was also seen
by Cassini's synthetic aperture radar in October 2004 and February 2005.
Toward the northeastern edge of the dark material a dark, circular spot in
the middle of a bright feature (see figure C) is an approximately
80-kilometer-wide (50-mile) crater identified in the February 2005 radar
data (see PIA07368 for the radar image).
The resolution of this new image is lower but sufficient to reveal
important similarities and differences between the two observations. Part
of the crater floor is quite dark compared to the surrounding material at
near-infrared wavelengths. This observation is consistent with the
hypothesis that the dark material consists of complex hydrocarbons that
have precipitated from the atmosphere and collected in areas of low
elevation. At radar wavelengths the crater floor is much more uniform and
there also are brightness differences seen by these two instruments
outside of the crater. Such comparisons give Cassini scientists important
clues about the roughness and composition of the surface material on
Titan.
Another interesting comparison is the "dark terrain" with small bright
features as seen by the radar (see PIA07367) and the essentially inverted
pattern (bright with small dark features) seen by the imaging science
subsystem cameras. In the mosaic, this area is in the top left
narrow-angle camera image.
Within the bright terrain at the top of the mosaic, just left of center,
lies a very intriguing feature: a strikingly dark spot from which diffuse
dark material appears to extend to the northeast. The origin of this
feature is not yet known, but it, too, lies within the radar image;
Cassini scientists will thus be able to study it using these complementary
observations.
The mosaic is centered on a region at 1 degree north latitude, 21 degree
west longitude on Titan.
The Cassini spacecraft narrow-angle camera images were taken using a
filter sensitive to wavelengths of polarized infrared light and were
acquired at distances ranging from approximately 148,300 to 112,800
kilometers (92,100 to 70,100 miles) from Titan. Resolution in the images
is about 1 to 2 kilometers (0.6 to 1.2 miles) per pixel.
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 team is based at
the Space Science Institute, Boulder, Colo.
For more information about the Cassini-Huygens mission, visit
http://saturn.jpl.nasa.gov and the Cassini imaging team home page,
http://ciclops.org.