CICLOPS: Cassini Imaging Central Laboratory for OPerationS
Petite Moon

A bright arc within Saturn's faint G ring holds a tiny gift.

A small moonlet is visible as a short streak near the ansa of the G ring arc in the upper-most of two versions of the same image. The second (bottom) version of the image has been brightened to enhance the visibility of the G ring. The other streaks in this version of the image are stars smeared by the camera's long exposure time of 26 seconds. This version of the image shows a gap in the G ring which was faintly visible in an earlier Cassini movie (see PIA08327).

The moonlet, dubbed S/2008 S 1, is likely a major source of the material of the G ring (see PIA 11148).

This view looks toward the sunlit side of the rings from about 1 degrees below the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 28, 2009. The view was acquired at a distance of approximately 1.2 million kilometers (746,000 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 Equinox Mission is a joint United States and European endeavor. 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 was designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini Equinox Mission visit, and

Credit: NASA/JPL/Space Science Institute
Released: May 29, 2009 (PIA 11503)
Image/Caption Information
  Petite Moon
PIA 11503

Avg Rating: 8.46/10

Full Size 1018x1450:
PNG 220 KB

Alliance Member Comments
mipsandbips (May 30, 2009 at 8:30 PM):
The path of the moonlet shows a closed path in the G ring,
however, the path in the G ring is not completely closed.
So, the question becomes at what rate (if ascertainable) is the
path of Aegaeon gaining closure in its orbit in the G ring or
by what measure is it losing it? The length of the streak
compared to the distance of a single orbit would be the
beginning of a very interesting hypothesis towards answering
that question.