The first artificial satellite in the Saturn system, the Cassini
spacecraft, returned images of the natural moons following a successful
insertion into orbit. This is an unmagnified view of the moon Rhea.
With a diameter of 1,528 kilometers (950 miles) across, Rhea is Saturn's
second largest moon. The Voyager spacecraft found that like Dione, Rhea
has one of its hemispheres covered with bright, wispy streaks which may
be water frost.
This view shows a heavily cratered surface, and thus it is most likely
ancient. Many of the craters visible here have central peaks. Cassini
soon will look for clues to help unlock the moon's geologic history. The
spacecraft is slated to fly by Rhea at a distance of only 500 kilometers
(311 miles) on Nov. 26, 2005.
The image was taken in visible light with the Cassini spacecraft narrow
angle camera on July 2, 2004, from a distance of about 990,000 kilometers
(615,000 miles) from Rhea and at a Sun-Rhea-spacecraft, or phase angle of
about 109 degrees. The image scale is 6 kilometers (4 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.
