Spoke Siblings

This group of spokes in Saturn's B ring extends over more than 5,000 kilometers (3,100 miles) radially across the ringplane.

The bright wedge to the left of center has a trailing edge (its top right edge) which is nearly radial and a leading edge which is sheared by about 30 degrees (forming a "Y" shape). The rest of the spokes also seem to be sheared by the same amount on both edges.

Scientists believe that spokes are essentially radial when they form. From this amount of shear, ring scientists deduce that the spokes in this group probably were all created at about the same time. Combining the amount of the spokes' shear with their radial distance from Saturn provides an approximate time when the features were created -- about 100 minutes before this image was taken.

This view looks toward the unlit side of the rings from about 47 degrees above the ringplane.

The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 7, 2007 at a distance of approximately 1.8 million kilometers (1.1 million miles) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 145 degrees. Image scale is 11 kilometers (7 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 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 . The Cassini imaging team homepage is at http://ciclops.org .

Credit: NASA/JPL/Space Science Institute