The visual and infrared mapping spectrometer on the Cassini spacecraft
has found evidence for a material dubbed "dirt" in Saturn's rings. The
observations indicate that some type of sorting mechanism is concentrating
this unidentified material in the gaps between the rings.
The images here show the rings just after Cassini successfully entered
Saturn's orbit. The infrared reflectance image shows the brightness of
scattered light transmitted through the rings. The thicker parts of the
rings block more light, while the thinner parts, like the Cassini
Division, let more light through. Assuming the rings are made of boulders,
they might appear as a multitude of tiny moons.
The water ice strength image shows the amount of water in the rings,
which appears to peak in the region of the A ring.
The "dirt" image shows that the so-called dirty material is most abundant
in the thinnest parts of the rings: the Cassini Division, in the Encke
and in other small gaps. This material appears remarkably similar to what
Cassini measured on Saturn's moon, Phoebe.
This color composite is a slightly smeared image in which multiple
measurements of the same radial distance are repeatedly measured as
indicated by the shallow diagonal banding. For example, the five red
dots in the Encke Gap are repeated measurements of the inner edge of the
gap.
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 was designed, developed and
assembled at JPL. The visual and infrared mapping spectrometer team is
based at the University of Arizona, Tucson, Ariz.
For more information, about the Cassini-Huygens mission visit,
http://saturn.jpl.nasa.gov. For more information
about the visual and infrared mapping spectrometer visit
http://wwwvims.lpl.arizona.edu/.
