Having now passed closer to Tethys than the Voyager 2 spacecraft, Cassini
has returned the best-ever natural color view of this icy Saturnian moon.
As seen here, the battered surface of Tethys (1,060 kilometers, or 659
miles across) has a neutral hue. The image here is a mosaic of two
footprints. Three images taken in the red, green and blue filters were
taken to form a natural color composite. The result reveals a world
nearly saturated with craters - many small craters lie on top of older,
larger ones, suggesting an ancient surface. At the top and along the
boundary between day and night, the moon's terrain has a grooved
appearance.
This moon is known to have a density very close to that of water,
indicating it is likely composed mainly of water ice. Its frozen
mysteries await Cassini's planned close flyby in September 2005.
The view shows primarily the trailing hemisphere of Tethys, which is the
side opposite the moon's direction of motion in its orbit. The image has
been rotated so that north on Tethys is up.
The images comprising this color view were taken with the Cassini
spacecraft narrow angle camera on Oct. 28, 2004, at a distance of about
256,000 kilometers (159,000 miles) from Tethys and at a
Sun-Tethys-spacecraft, or phase, angle of 50 degrees. The image scale is
1.5 kilometers (0.9 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 Cassini-Huygens mission for NASA's Office of Space
Science, 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.
