PIA08825: Science at the Shadow Boundary

Science at the Shadow Boundary


Saturn's shadow cloaks the faint D ring at the bottom of this image.

Observations of the shadow boundary, like this one, enable scientists to clearly detect and measure the brightness of diffuse and faint ring features like the inner part of the D-ring. Such brightness measurements are often difficult to make, but the shadow region provides a very dark standard against which to compare the D ring, as the only brightness in the shadow is provided by the background of space.

The bright specks across the scene, both in the bright rings and in the shadow, are either stars or cosmic ray hits on the camera's detector.

This view looks toward the unlit side of the rings from about 42 degrees above the ringplane.

The image was taken in visible light with the Cassini spacecraft wide-angle camera on Nov. 12, 2006. Cassini was then at a distance of approximately 1.4 million kilometers (900,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 152 degrees. Image scale is 8 kilometers (5 miles) per pixel.

Background Info:

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 operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov/home/index.cfm . The Cassini imaging team homepage is at http://ciclops.org .

Cataloging Keywords:

Name Value Additional Values
Target Saturn Rings D Ring, Saturn
System Saturn
Target Type Ring Planet
Mission Cassini-Huygens
Instrument Host Cassini Orbiter
Host Type Orbiter
Instrument Imaging Science Subsystem (ISS)
Detector Wide Angle Camera
Extra Keywords Grayscale, Shadow, Visual
Acquisition Date
Release Date 2006-12-21
Date in Caption 2006-11-12
Image Credit NASA/JPL/Space Science Institute
Source photojournal.jpl.nasa.gov/catalog/PIA08825
Identifier PIA08825