Seen from a viewpoint nearly coincident with the ringplane, the bright arc
within the G ring appears even brighter with its ring material
concentrated in the center of this image.
This partial arc is much narrower than the ring and extends only one-sixth
of the way around the G ring. The arc is 250 kilometers (150-miles) wide
and extends 150,000 kilometers (93,000 miles) in orbital longitude. The
collection of particles that make up the arc is held in place by a
resonance, or gravitational disturbance, from the moon Mimas.
The motion of the spacecraft smeared background stars into streaks because
the camera needed a very long exposure time of 26 seconds to capture light
reflected from the faint ring. The image was taken in visible light with
the Cassini spacecraft narrow-angle camera on Jan. 28, 2009. This view
looks toward the sunlit side of the rings from just barely below the
ringplane.
The view was acquired at a distance of approximately 1.2 million
kilometers (750,000 miles) from Saturn and at a Sun-Saturn-spacecraft, or
phase, angle of 27 degrees. Image scale is 7 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 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.
