The bright arc of material in Saturn's G ring is seen here as it rounds
the ring's edge, or ansa. The ring arc orbits Saturn along the inner edge
of the G ring.
Cassini spacecraft scientists think the arc contains a population of
relatively large, icy particles held in place by a gravitational an
orbital resonance with the moon Mimas. Micrometeoroids collide with the
large particles, releasing smaller, dust-sized particles that brighten the
arc. The plasma in the giant planet's magnetic field sweeps through this
arc continually, dragging out the fine particles and creating the G ring.
The ring arc orbits Saturn along the inner edge of the G ring.
The diffuse glow at left shows the extended nature of this faint ring.
The ring moved against the background stars during this exposure, creating
the star trails seen here.
The view looks toward the sunlit side of the rings from less than a degree
below the ringplane.
The upper, brighter ring section is the one closer to Cassini. Here, the
ring arc is coming toward Cassini and moving toward right as it rounds the
ansa.
The image was taken in visible light with the Cassini spacecraft
narrow-angle camera on Aug. 22, 2008. The view was acquired at a distance
of approximately 1.2 million kilometers (740,000 miles) from Saturn and at
a Sun-Saturn-spacecraft, or phase, angle of 13 degrees. Image scale is 7
kilometers (4 miles) per pixel in the radial, or outward-from-Saturn,
direction.
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.
