A bright spoke extends across the unilluminated side of Saturn's B ring
about the same distance as that from London to Cairo. The background ring
material displays some azimuthal (i.e., left to right) asymmetry.
The radial (outward from Saturn) direction is up in this view. A
noticeable kink in the spoke occurs very close to the radius where ring
particles orbit the planet at the speed of Saturn's magnetic field. Such a
connection is most intriguing to scientists studying these ghostly ring
phenomena.
If gravity alone were affecting the spoke material, there would be no kink
and the entire spoke would be angled toward right, like the bottom
portion. That it bends to the left above the kink indicates that some
other force, possibly related to the magnetic field, is acting on the
spoke material. The shape might also indicate that the spoke did not form
in a radial orientation, thus challenging scientists' assumptions about
these features.
This view looks toward the unlit side of the rings from about 58 degrees
above the ringplane.
The image was taken in visible light with the Cassini spacecraft
narrow-angle camera on Jan. 23, 2007 at a distance of approximately 1.6
million kilometers (1 million miles) from Saturn. Image scale is 10
kilometers (6 miles) per pixel.
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.
