This pair of images, taken by the Cassini spacecraft radar mapper on two
different Titan passes on Dec. 11, 2006 (T21 left), and Oct. 29, 2005 (T8
right), represent two different views of a field of dunes located near 9.4
degrees south latitude by 290 degrees west longitude.
The images were taken in synthetic aperture mode and have a resolution of
approximately 500 meters (1,640 feet). North is toward the top of both
images, and each image is approximately 400 kilometers (250 miles) long by
275 kilometers (170 miles) wide. The images are different only because the
radar instrument illuminated the dunes from different directions. Acting
somewhat like a flash camera, the radar sends out microwave pulses and
makes an image from the pulses after they are reflected back. Imagine that
both the "camera" and the "flash" come from the left in the left image and
from the top in the right image.
Most obvious differences are seen in the large bright feature at the
center of both images. At left, its left edge is brighter, emphasizing the
more steep slopes there. Farther left, the dunes are more clearly defined
in the right image as their faces are caught by the illumination. However,
since the dunes are visible in both images, it is likely that the
materials making up the dark and light stripes are also somehow different.
More detailed studies of how materials on Titan reflect and scatter at
different angles are giving us clues about what different materials might
be present in this cold and distant world.
For more information about dunes on Titan, see PIA03567.
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 was designed, developed and assembled at JPL. The radar
instrument was built by JPL and the Italian Space Agency, working with
team members from the United States and several European countries.
For more information about the Cassini-Huygens mission visit
http://saturn.jpl.nasa.gov/home/index.cfm.
